14CFR vol1 part25 - 276 pages

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(e) Information needed to apply protective
(f) All data relative to structural fasteners
(g) A list of special tools needed.
(h) In addition, for level 4 airplanes, the
PART 25 - AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY
Subpart A - General
25.1 Applicability.
25.2 Special retroactive requirements.
25.3 Special provisions for ETOPS type design approvals.
25.5 Incorporations by reference.
25.33
25.101
25.103
25.105
25.107
25.109
25.111
25.113
25.115
...

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14 CFR Ch. I (1-1-19 Edition)
25.331
25.333
25.335
25.337
25.341
25.343
25.345
25.349
25.351
25.525 Application of loads.
25.527 Hull and main float load factors.
25.529 Hull and main float landing conditions.
25.531 Hull and main float takeoff condition.
25.533 Hull and main float bottom pressures.
25.535 Auxiliary float loads.
25.537 Seawing loads.
25.361 Engine and auxiliary power unit
25.362 Engine failure loads.
25.363 Side load on engine and auxiliary
25.365 Pressurized compartment loads.
...

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25.723 Shock absorption tests.
25.725-25.727 [Reserved]
25.729 Retracting mechanism.
25.731 Wheels.
25.733 Tires.
25.735 Brakes and braking systems.
25.737 Skis.
25.857 Cargo compartment classification.
25.858 Cargo
25.859 Combustion heater fire protection.
25.863 Flammable fluid fire protection.
25.865 Fire protection of flight controls, engine mounts, an...
25.867 Fire protection: other components.
25.869 Fire protection: systems.
25.751
25.753
25.755
25.771 Pilot compartment.
25.772 Pilot compartment doors.
25.773 Pilot compartment view.
25.775 Windshields and windows.
...

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14 CFR Ch. I (1-1-19 Edition)
25.997 Fuel strainer or filter.
25.999 Fuel system drains.
25.1001 Fuel jettisoning system.
25.1192
25.1193
25.1195
25.1197
25.1199
25.1201
25.1203
25.1207
25.1011
25.1013
25.1015
25.1017
25.1019
25.1021
25.1023
25.1025
25.1027
...

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25.1395 Maximum intensities in overlapping
25.1397 Color specifications.
25.1399 Riding light.
25.1401 Anticollision light system.
25.1403 Wing icing detection lights.
25.1411 General.
25.1415 Ditching equipment.
25.1419 Ice protection.
25.1420 Supercooled large drop icing conditions.
25.1421 Megaphones.
25.1423 Public address system.
25.1431 Electronic equipment.
25.1433 Vacuum systems.
25.1435 Hydraulic systems.
25.1438 Pressurization and pneumatic systems.
25.1439 Protective breathing equipment.
25.1441 Oxygen equipment and supply.
25.1443 Minimum mass flow of supplemental
25.1445 Equipment standards for the oxygen
25.1447 Equipment standards for oxygen dispensing units.
25.1449 Means for determining use of oxygen.
...

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14 CFR Ch. I (1-1-19 Edition)
44701, 44702 and 44704.
24, 1964, unless otherwise noted.
1. Applicability. Contrary provisions of the
2. General modifications. Except as modified
3. Specific conditions for approval. An applicant for any ap...
(a) Increase in take-off power limitation - 
1,200 to 1,350 horsepower. The engine take-off
(b) Increase in take-off power limitation to
(c) Installation of engines of not more than
1,830 cubic inches displacement and not having
1,350 horsepower which necessitate a major
(d) Installation of engines of more than 1,830
4b is extremely difficult to accomplish and
4. Establishment of new maximum certificated
(a) Weights-25,200 to 26,900 for the DC-3 and
18,500 to 19,500 for the L-18. New maximum
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(b) Weights of more than 26,900 for the DC-3
18 airplanes justifies it, he is authorized to
(c) Airplane flight manual-performance operating information...
(d) Performance operating limitations. Each
5. Reference. Unless otherwise provided, all
1. Applicability. Contrary provisions of 14
2. General.
(a) The passenger capacity may not exceed
60. If more than 60 passenger seats are installed, then:
(b) For airplanes outfitted with interior
(c) The AFM must include appropriate limitation(s) to requir...
(d) The airplane may not be offered for
(e) A placard stating that  - Operations involving the carri...
(f) For passenger capacities of 45 to 60 passengers, analysi...
(g) In order for any airplane certified under
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14 CFR Ch. I (1-1-19 Edition)
3. General. Unless otherwise noted, compliance is required w...
4. Occupant Protection.
(a) Firm Handhold. In lieu of the requirements of Section 25...
(b) Injury criteria for multiple occupancy
49 CFR part 572, subpart F. Torso contact
571.214, section S6.13.5 (49 CFR 571.214).
(i) All seat positions need to be occupied by
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(c) For the vertical test, conducted in accordance with the ...
Section 25.562(b)(1), Hybrid II ATDs or equivalent
5. Direct View. In lieu of the requirements
6. Passenger Information Signs. Compliance
Section 25.791(a), when smoking is to be prohibited,
7. Distance Between Exits. For an airplane
(a) Each passenger seat must be located
(b) The number of passenger seats located
(c) The total number of passenger seats in
Section 25.807(g) for the original certified exits or
(d) A distance of more than 60 feet between
8. Emergency Exit Signs. In lieu of the requirements of Sect...
(a) The sign can be read from the aisle
(b) The sign can be read from the aisle adjacent to the pass...
9. Emergency Lighting.
(a) Exit Signs. In lieu of the requirements of
Section 25.812(b)(1), for airplanes that have a passenger se...
(b) Floor Proximity Escape Path Marking. In
(c) Transverse Separation of the Fuselage. In
Section 25.812(l) except as follows:
10. Interior doors. In lieu of the requirements of Section 2...
...

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14 CFR Ch. I (1-1-19 Edition)
(c) Each door between any passenger seat
Section 25.561.
(d) Doors installed across a longitudinal
(e) Each door between any passenger seat
(f) Each door between any passenger seat
11. Width of Aisle. Compliance is required
12. Materials for Compartment Interiors.
25.
13. Fire Detection. For airplanes with a type
Section 25.854.
14. Cooktops. Each cooktop must be designed and installed to...
(a) Means, such as conspicuous burner-on
(b) Sufficient design means must be included to restrain coo...
(c) Placarding must be installed which prohibits the use of ...
(d) Means must be provided to address the
(e) The surfaces of the galley surrounding
(f) The cooktop must be ventilated with a
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Section 25.3
(g) Means must be provided to contain
(h) Cooktop installations must provide
(i) A means to shut off power to the
(j) If the cooktop is required to have a lid
15. Hand-Held Fire Extinguishers.
(a) For airplanes that were originally type
(b) Extinguishers must be evenly distributed throughout the ...
16. Security. The requirements of Section 25.795 are
2009]
Subpart A - General
Section 25.1
(a) This part prescribes airworthiness
(b) Each person who applies under
Section 25.2 Special
(a) Irrespective of the date of application, each applicant ...
25.721(d),
25.783(g),
25.785(c), 25.803(c)(2) through (9), 25.803
(d) and (e), 25.807 (a), (c), and (d), 25.809
(f) and (h), 25.811, 25.812, 25.813 (a), (b),
...

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Section 25.5
14 CFR Ch. I (1-1-19 Edition)
(i) K25.1.4(a), fuel system pressure
(c) Airplanes with more than two engines. An applicant for E...
Section 25.1535 for an airplane manufactured
Subpart B - Flight
2007]
Section 25.5 Incorporations by reference.
(a) The materials listed in this section are incorporated by...
552(a) and 1 CFR part 51. These materials are incorporated a...
6030, or go to: http://www.archives.gov/
(b) The following materials are available for purchase from ...
9169, Mar. 5, 2018]
Section 25.21
(a) Each requirement of this subpart
(b) [Reserved]
(c) The controllability, stability,
(d) Parameters critical for the test
(e) If compliance with the flight
(f) In meeting the requirements of
(g) The requirements of this subpart
...

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Section 25.25
25.251(b) through (e), must be met in
(d) must be met in the landing configuration in the icing co...
25.113, 25.115, 25.121, 25.123, 25.143(b)(1),
(b)(2), and (c)(1), 25.149, 25.201(c)(2),
25.207(c), (d), and (e)(1), 25.239, and
25.251(b) through (e), must be met in
25.251(b) through (e), must be met in
25.207(c) and (d) must be met in the
(d) of Appendix O, assuming normal operation of the airplane...
1970; Amdt. 25-42, 43 FR 2320, Jan. 16, 1978;
25-121, 72 FR 44665, Aug. 8, 2007 Amdt. 25-135,
76 FR 74654, Dec. 1, 2011; Amdt. 25-140, 79 FR
65524, Nov. 4, 2014]
Section 25.23 Load distribution limits.
(a) Ranges of weights and centers of
(b) The load distribution limits may
Section 25.25 Weight limits.
(a) Maximum weights. Maximum
(b) Minimum weight. The minimum
12:50 Apr 30, 2019
...

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Section 25.27
14 CFR Ch. I (1-1-19 Edition)
1970; Amdt. 25-63, 53 FR 16365, May 6, 1988]
Section 25.27
(a) The extremes selected by the applicant;
(b) The extremes within which the
(c) The extremes within which compliance with each applicabl...
Section 25.29 Empty
(a) The empty weight and corresponding center of gravity mus...
Section 25.959; and
(i) Oil;
(b) The condition of the airplane at
1978; Amdt. 25-72, 55 FR 29774, July 20, 1990]
Section 25.31 Removable ballast.
Section 25.33 Propeller speed and pitch limits.
(a) The propeller speed and pitch
(b) There must be a propeller speed
(c) The means used to limit the low
1984; Amdt. 25-72, 55 FR 29774, July 20, 1990]
Section 25.101 General.
(a) Unless otherwise prescribed, airplanes must meet the app...
...

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Section 25.103
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
10,000
15,000
20,000
25,000
0.403
0.0023769
0.00849
0.99508
(c) The performance must correspond
(d) Unless otherwise prescribed, the
...

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Section 25.105
14 CFR Ch. I (1-1-19 Edition)
(c) Starting from the stabilized trim
(d) In addition to the requirements of
2007]
Section 25.105 Takeoff.
(a) The takeoff speeds prescribed by
Section 25.107, the accelerate-stop distance
Section 25.113, and the net takeoff flight path
Section 25.21(g):
(i) The stall speed at maximum takeoff weight exceeds that i...
3 knots CAS or 3 percent of VSR; or
Section 25.121(b) is greater than one-half of
(b) No takeoff made to determine the
(c) The takeoff data must be based
(i) Smooth, dry and wet, hard-surfaced runways; and
(d) The takeoff data must include,
1998; Amdt. 25-121, 72 FR 44665, Aug. 8, 2007;
Section 25.107 Takeoff speeds.
(a) V1 must be established in relation
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...

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Section 25.107
(b) V2MIN, in terms of calibrated airspeed, may not be less ...
(i) Two-engine and three-engine turbopropeller and reciproca...
(i) Turbopropeller and reciprocating
Section 25.149.
(c) V2, in terms of calibrated airspeed, must be selected by...
(d) VMU is the calibrated airspeed at
(e) VR, in terms of calibrated airspeed, must be selected in...
(i) V1;
35 feet above the takeoff surface; or
(f) VLOF is the calibrated airspeed at
(g) VFTO, in terms of calibrated airspeed, must be selected ...
(h) In determining the takeoff speeds
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Section 25.109
14 CFR Ch. I (1-1-19 Edition)
1976; Amdt. 25-42, 43 FR 2320, Jan. 16, 1978;
25-94, 63 FR 8848, Feb. 23, 1998; Amdt. 25-108,
67 FR 70826, Nov. 26, 2002; Amdt. 25-121, 72 FR
44665, Aug. 8, 2007; Amdt. 25-135, 76 FR 74654,
Section 25.109 Accelerate-stop distance.
(a) The accelerate-stop distance on a
(i) Accelerate the airplane from a
(i) Accelerate the airplane from a
(b) The accelerate-stop distance on a
(a) of this section, except that the runway is wet and the c...
(i) The wheel brakes stopping force
(c) The wet runway braking coefficient of friction for a smo...
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Section 25.109
0.30
0.50
0.80
(d) At the option of the applicant, a
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Section 25.111
14 CFR Ch. I (1-1-19 Edition)
(e) Except as provided in paragraph
(f)(1) of this section, means other than
(f) The effects of available reverse
(g) The landing gear must remain extended throughout the acc...
(h) If the accelerate-stop distance includes a stopway with ...
(i) A flight test demonstration of the
1978; Amdt. 25-92, 63 FR 8318, Feb. 18, 1998]
Section 25.111
(a) The takeoff path extends from a
(b) During the acceleration to speed
(c) During the takeoff path determination in accordance with...
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Section 25.113
(i) 1.2 percent for two-engine airplanes;
(i) With the most critical of the takeoff ice accretion(s) d...
(d) The takeoff path must be determined by a continuous demo...
(e) For airplanes equipped with
1965; Amdt. 25-42, 43 FR 2321, Jan. 16, 1978;
25-72, 55 FR 29774, July 20, 1990; Amdt. 25-94,
63 FR 8848, Feb. 23, 1998; Amdt. 25-108, 67 FR
70826, Nov. 26, 2002; Amdt. 25-115, 69 FR 40527,
8, 2007; Amdt. 25-140, 79 FR 65525, Nov. 4, 2014]
Section 25.113 Takeoff distance and takeoff
(a) Takeoff distance on a dry runway
35 feet above the takeoff surface, determined under Section ...
(b) Takeoff distance on a wet runway
15 feet above the takeoff surface,
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Section 25.115
14 CFR Ch. I (1-1-19 Edition)
35 feet above the takeoff surface, determined under Section ...
(c) If the takeoff distance does not include a clearway, the...
(i) The horizontal distance along the
Section 25.111.
(i) The horizontal distance along the
15 feet above the takeoff surface,
35 feet above the takeoff surface, as determined under Secti...
Section 25.111.
1970; Amdt. 25-92, 63 FR 8320, Feb. 18, 1998]
Section 25.115 Takeoff flight path.
(a) The takeoff flight path shall be
(b) The net takeoff flight path data
(c) The prescribed reduction in climb
1998]
Section 25.117 Climb: general.
Section 25.119 Landing climb: All-engines-operating.
8 seconds after initiation of movement
(a) In non-icing conditions, with a
(b) In icing conditions with the most
...

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Section 25.121
Section 25.111.
(b) Takeoff; landing gear retracted. In
(i) The critical engine inoperative,
(b)(1) of this section must be met:
(i) In non-icing conditions; and
Section 25.21(g), if in the configuration used to
Section 25.121(b) is greater than one-half of
(c) Final takeoff. In the en route configuration at the end ...
Section 25.111:
(i) The critical engine inoperative
(c)(1) of this section must be met:
(i) In non-icing conditions; and
Section 25.121(b) is greater than one-half of
(d) Approach. In a configuration corresponding to the normal...
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Section 25.123
14 CFR Ch. I (1-1-19 Edition)
(i) The critical engine inoperative,
(d)(1) of this section must be met:
(i) In non-icing conditions; and
Section 25.21(g). The climb speed selected for
(d)(1)(iii) of this section, does not exceed that for non-ic...
1995; Amdt. 25-108, 67 FR 70826, Nov. 26, 2002;
25-140, 79 FR 65525, Nov. 4, 2014]
Section 25.123
(a) For the en route configuration,
(b) The one-engine-inoperative net
Section 25.21(g), if:
(i) A speed of 1.18  - VSR0 with the en
(c) For three- or four-engine airplanes, the two-engine-inop...
2007; Amdt. 25-140, 79 FR 65525, Nov. 4, 2014]
Section 25.125 Landing.
(a) The horizontal distance necessary
Section 25.21(g), if VREF for icing conditions exceeds VREF ...
(b) In determining the distance in
(i) In non-icing conditions, VREF may
...

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Section 25.143
(c) For landplanes and amphibians,
(i) Is safe and reliable;
(d) For seaplanes and amphibians,
(e) For skiplanes, the landing distance on snow must be dete...
(f) The landing distance data must
(g) If any device is used that depends
50467, Aug. 31, 2007; Amdt. 25-140, 79 FR 65525,
Section 25.143 General.
(a) The airplane must be safely controllable and maneuverabl...
(b) It must be possible to make a
(c) The airplane must be shown to be
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Section 25.143
14 CFR Ch. I (1-1-19 Edition)
(d) The following table prescribes, for
(e) Approved operating procedures or
2V
2 + XX
(f) When demonstrating compliance
(g) When maneuvering at a constant
(h) The maneuvering capabilities in a
30Section
40Section
40Section
40Section
...

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Section 25.145
1978; Amdt. 25-84, 60 FR 30749, June 9, 1995;
25-129, 74 FR 38339, Aug. 3, 2009; Amdt. 25-140,
79 FR 65525, Nov. 4, 2014]
Section 25.145
(a) It must be possible, at any point
Section 25.103(b)(6) and stall identification (as
(b) With the landing gear extended,
(c) It must be possible, without exceptional piloting skill,...
(d) If gated high-lift device control
1970; Amdt. 25-72, 55 FR 29774, July 20, 1990;
25-98, 64 FR 6164, Feb. 8, 1999; 64 FR 10740,
26, 2002]
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Section 25.147
14 CFR Ch. I (1-1-19 Edition)
Section 25.147 Directional and lateral control.
(a) Directional control; general. It must
(b) Directional control; airplanes with
(c) Lateral control; general. It must be
1.3 VSR1, with - 
(d) Lateral control; roll capability. With
(e) Lateral control; airplanes with four
(f) Lateral control; all engines operating. With the engines...
1978; Amdt. 25-72, 55 FR 29774, July 20, 1990;
Section 25.149 Minimum control speed.
(a) In establishing the minimum control speeds required by t...
(b) VMC is the calibrated airspeed at
(c) VMC may not exceed 1.13 VSR
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Section 25.149
(i) Windmilling;
(d) The rudder forces required to
20 degrees.
(e) VMCG, the minimum control speed
(f) VMCL, the minimum control speed
5 degrees. VMCL must be established
(g) For airplanes with three or more
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Section 25.161
14 CFR Ch. I (1-1-19 Edition)
(i) Minimum power or thrust; and
(h) In demonstrations of VMCL and
150 pounds;
5 seconds; and
1978; Amdt. 25-72, 55 FR 29774, July 20, 1990; 55
30749, June 9, 1995; Amdt. 25-108, 67 FR 70827,
Section 25.161 Trim.
(a) General. Each airplane must meet
(b) Lateral and directional trim. The
(c) Longitudinal trim. The airplane
1.3 VSR1, with the landing gear retracted, and the flaps (i)...
(d) Longitudinal, directional, and lateral trim. The airplan...
(e) Airplanes with four or more engines. Each airplane with ...
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Section 25.175
1970; Amdt. 25-38, 41 FR 55466, Dec. 20, 1976;
Section 25.175 Demonstration of static longitudinal stabilit...
Section 25.171 General.
(a) Climb. The stick force curve must
85 and 115 percent of the speed at which
(i) Wing flaps retracted;
(b) Cruise. Static longitudinal stability must be shown in t...
50 pounds), with - 
(i) The wing flaps retracted;
Section 25.1521), except that the power need
1965]
Section 25.173 Static longitudinal stability.
Section 25.175, the characteristics of the elevator control ...
(a) A pull must be required to obtain
(b) The airspeed must return to within 10 percent of the ori...
Section 25.175(b), when the control force is
(c) The average gradient of the stable
(d) Within the free return speed range
12:50 Apr 30, 2019
...

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Section 25.177
14 CFR Ch. I (1-1-19 Edition)
(v) The airplane trimmed for level
50 pounds), with - 
(i) Wing flaps, center of gravity position, and weight as sp...
(i) Wing flap, center of gravity position, and weight as spe...
(c) Approach. The stick force curve
(d) Landing. The stick force curve
(i) Power or thrust off, and
1965; Amdt. 25-108, 67 FR 70827, Nov. 26, 2002;
Section 25.177 Static lateral-directional stability.
(a) The static directional stability
(b) The static lateral stability (as
(i) Gradual;
(c) The following requirement must
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Section 25.201
(d) For sideslip angles greater than
Section 25.181
(a) Any short period oscillation, not
(b) Any combined lateral-directional
1990; 55 FR 37607, Sept. 12, 1990; Amdt. 25-108,
67 FR 70827, Nov. 26, 2002]
Section 25.201
(a) Stalls must be shown in straight
(b) In each condition required by
Section 25.103(b)(6).
(c) The following procedures must be
(d) The airplane is considered stalled
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Section 25.203
14 CFR Ch. I (1-1-19 Edition)
1995; Amdt. 25-108, 67 FR 70827, Nov. 26, 2002]
Section 25.203 Stall characteristics.
(a) It must be possible to produce and
(b) For level wing stalls, the roll occurring between the st...
(c) For turning flight stalls, the action of the airplane af...
1995]
Section 25.207 Stall warning.
(a) Stall warning with sufficient margin to prevent inadvert...
(b) The warning must be furnished either through the inheren...
(c) When the speed is reduced at rates
(d) In addition to the requirement of
Section 25.103(b)(5), VSW, in each normal configuration, mus...
(e) In icing conditions, the stall
Section 25.21(g), for each configuration used in
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Section 25.231
(f) The stall warning margin must be
(g) Stall warning must also be provided in each abnormal con...
(h) The following stall warning margin is required for fligh...
(i) One second after the onset of stall
(i) In showing compliance with paragraph (h) of this section...
1965; Amdt. 25-42, 43 FR 2322, Jan. 16, 1978;
25-129, 74 FR 38339, Aug. 3, 2009; Amdt. 25-140,
79 FR 65526, Nov. 4, 2014]
Section 25.231 Longitudinal
(a) Landplanes may have no uncontrollable tendency to nose o...
(b) For seaplanes and amphibians,
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Section 25.233
14 CFR Ch. I (1-1-19 Edition)
26, 2002]
Section 25.233 Directional stability and control.
(a) There may be no uncontrollable
25 knots at any speed at which the airplane may be expected ...
Section 25.237.
(b) Landplanes must be satisfactorily
(c) The airplane must have adequate
1970; Amdt. 25-42, 43 FR 2322, Jan. 16, 1978;
25-108, 67 FR 70828, Nov. 26, 2002]
Section 25.235
Section 25.237
(a) For land planes and amphibians,
25 knots.
(i) Non-icing conditions, and
Section 25.21(g).
(b) For seaplanes and amphibians,
0.2 VSR0, whichever is greater, except
26, 2002; Amdt. 25-121, 72 FR 44668, Aug. 8,
2007; Amdt. 25-140, 79 FR 65525, Nov. 4, 2014]
...

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Section 25.253
(c) In the water conditions of paragraph (b) of this section...
Section 25.251
(a) The airplane must be demonstrated in flight to be free f...
(b) Each part of the airplane must be
(c) Except as provided in paragraph
(d) of this section, there may be no buffeting condition, in...
(d) There may be no perceptible buffeting condition in the c...
(e) For an airplane with MD greater
1970; Amdt. 25-72, 55 FR 29775, July 20, 1990;
Section 25.253 High-speed characteristics.
(a) Speed increase and recovery characteristics. The followi...
(i) Exceptional piloting strength or
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Section 25.255
14 CFR Ch. I (1-1-19 Edition)
(i) An excessive positive load factor
(b) Maximum speed for stability characteristics, VFC/MFC. VF...
25.177(a) through (c), and 25.181 must be
(c) Maximum speed for stability characteristics in icing con...
25.175(b)(1), 25.177(a) through (c), and
25.181 must be met, is the lower of:
1970; Amdt. 25-54, 45 FR 60172, Sept. 11, 1980;
25-84, 60 FR 30750, June 9, 1995; Amdt. 25-121,
72 FR 44668, Aug. 8, 2007; Amdt. 25-135, 76 FR
74654, Dec. 1, 2011; Amdt. 25-140,79 FR 65525,
Section 25.255 Out-of-trim characteristics.
(a) From an initial condition with
(b) In the out-of-trim condition specified in paragraph (a) ...
(c) Except as provided in paragraphs
(d) and (e) of this section, compliance
g.
(d) If the procedure set forth in paragraph (c)(2) of this s...
(e) During flight tests required by
12:50 Apr 30, 2019
...

Page 39 -   PAGE

Section 25.305
(f) In the out-of-trim condition specified in paragraph (a) ...
Subpart C - Structure
Section 25.301 Loads.
(a) Strength requirements are specified in terms of limit lo...
(b) Unless otherwise provided, the
(c) If deflections under load would
1970]
Section 25.303
Section 25.305
(a) The structure must be able to
(b) The structure must be able to
(c) Where structural flexibility is
(d) [Reserved]
(e) The airplane must be designed to
12:50 Apr 30, 2019

Page 40 -   PAGE

Section 25.307
14 CFR Ch. I (1-1-19 Edition)
(f) Unless shown to be extremely improbable, the airplane mu...
1970; Amdt. 25-54, 45 FR 60172, Sept. 11, 1980;
25-86, 61 FR 5220, Feb. 9, 1996]
Section 25.307 Proof of structure.
(a) Compliance with the strength and
(b)-(c) [Reserved]
(d) When static or dynamic tests are
1970; Amdt. 25-54, 45 FR 60172, Sept. 11, 1980;
59429, Oct. 2, 2014]
Section 25.321 General.
(a) Flight load factors represent the
(b) Considering compressibility effects at each speed, compl...
(c) Enough points on and within the
(d) The significant forces acting on
1970; Amdt. 25-86, 61 FR 5220, Feb. 9, 1996]
Section 25.331 Symmetric maneuvering conditions.
(a) Procedure. For the analysis of the
12:50 Apr 30, 2019
...

Page 41 -   PAGE

Section 25.331
(b) and (c) of this section, the effect of
(b) Maneuvering balanced conditions.
(c) Maneuvering pitching conditions.
Section 25.333(b)) and the cockpit pitch control is suddenly...
12:50 Apr 30, 2019
Section 25.337 is achieved. As a separate condition, nose-do...
(i) The airplane is assumed to be flying in steady level fli...

Page 42 -   PAGE

Section 25.333
14 CFR Ch. I (1-1-19 Edition)
1970; Amdt. 25-46, 43 FR 50594, Oct. 30, 1978; 43
1978; Amdt. 25-72, 55 FR 29775, July 20, 1990; 55
5220, Feb. 9, 1996; Amdt. 25-91, 62 FR 40704,
11, 2014]
Section 25.333 Flight maneuvering envelope.
(a) General. The strength requirements must be met at each c...
Section 25.1501.
(b) Maneuvering envelope.
12:50 Apr 30, 2019
(v) Airplane loads that occur beyond

Page 43 -   PAGE

Section 25.335
(a) Design cruising speed, VC. For VC,
Section 25.341(a)(5)(i)). However VC need not
(b) Design dive speed, VD. VD must be
1.5g (0.5g acceleration increment). The
12:50 Apr 30, 2019
Section 25.335

Page 44 -   PAGE

Section 25.337
14 CFR Ch. I (1-1-19 Edition)
(c) Design maneuvering speed VA. For
(i) n is the limit positive maneuvering load factor at VC; a...
(d) Design speed for maximum gust intensity, VB.
498w -
Section 25.341(a)(5)(i);
5.3 + Section
Section 25.337 Limit maneuvering load factors.
2w
(i) VB may be chosen to provide an
(e) Design flap speeds, VF. For VF, the
(a) Except where limited by maximum (static) lift coefficien...
(b) The positive limit maneuvering
10,000) except that n may not be less
3.8 - where W is the design maximum
(c) The negative limit maneuvering
12:50 Apr 30, 2019
1970; Amdt. 25-86, 61 FR 5220, Feb. 9, 1996;
...

Page 45 -   PAGE

Section 25.341
350 feet must be investigated to find
2 -
4-;
12:50 Apr 30, 2019
Section 25.1527 (feet).
(b) Continuous turbulence design criteria. The dynamic respo...
Section 25.341 Gust and turbulence loads.
(a) Discrete Gust Design Criteria. The
1970]
(i) At airplane speeds between VB and
Section 25.341(a)(5)(i).
(d) Maneuvering load factors lower

Page 46 -   PAGE

Section 25.341
14 CFR Ch. I (1-1-19 Edition)
(i) At airplane speeds between VB and
24,000 feet and is then constant at 79 fps
(b)(3)(i) of this section.
(b)(3) of this section. The value of limit
(c) Supplementary gust conditions for
12:50 Apr 30, 2019
(b)(4) and (5) of this section, the following equation must ...

Page 47 -   PAGE

Section 25.345
Section 25.343 Design fuel and oil loads.
(a) The disposable load combinations
(f), as applicable, may be selected.
(b) If a structural reserve fuel condition is selected, it m...
(i) A maneuvering load factor of +
2.25; and
85% of the gust velocities prescribed in
Section 25.341(a)(4) and 85% of the turbulence
Section 25.345 High lift devices.
(a) If wing flaps are to be used during
(b) The airplane must be designed for
(a) of this section, except that the airplane load factor ne...
12:50 Apr 30, 2019
9533, Mar. 8, 1996; Doc. No. FAA-2013-0142; 79
4762, Jan. 29, 2015; 80 FR 6435, Feb. 5, 2015]
1968; Amdt. 25-72, 55 FR 37607, Sept. 12, 1990;
25-141, 79 FR 73468, Dec. 11, 2014]

Page 48 -   PAGE

Section 25.349
14 CFR Ch. I (1-1-19 Edition)
(c) If flaps or other high lift devices
(b).
(d) The airplane must be designed for
1978; Amdt. 25-72, 55 FR 37607, Sept. 17, 1990;
25-91, 62 FR 40704, July 29, 1997; Amdt. 25-141,
79 FR 73468, Dec. 11, 2014]
Section 25.349
(a) Maneuvering. The following conditions, speeds, and ailer...
(b) Unsymmetrical gusts. The airplane
Section 25.341(a), or the wing maximum airload derived indir...
Section 25.341(a). It must be assumed that 100
1970; Amdt. 25-86, 61 FR 5222, Feb. 9, 1996;
Section 25.351
(a) With the airplane in unaccelerated flight at zero yaw, i...
12:50 Apr 30, 2019

Page 49 -   PAGE

Section 25.362
(b) With the cockpit rudder control
(c) With the airplane yawed to the
(d) With the airplane yawed to the
Section 25.361 Engine and auxiliary power
(a) For engine installations - 
(i) A limit engine torque corresponding to takeoff power/thr...
1g level flight loads. In the absence of
(i) For turbopropeller installations,
(i) Sudden maximum engine deceleration due to malfunction or...
(b) For auxiliary power unit installations, the power unit m...
Section 25.362
(a) For engine mounts, pylons, and
(b) The ultimate loads developed
12:50 Apr 30, 2019

Page 50 -   PAGE

Section 25.363
14 CFR Ch. I (1-1-19 Edition)
Section 25.363 Side load on engine and auxiliary power unit ...
(a) Each engine and auxiliary power
Section 25.333(b).
(b) The side load prescribed in paragraph (a) of this sectio...
(a) The airplane structure must be
(b) The external pressure distribution
(c) If landings may be made with the
(d) The airplane structure must be
1.33 for airplanes to be approved for operation to 45,000 fe...
1.67 for airplanes to be approved for operation above 45,000...
(f) In complying with paragraph (e) of
(g) Bulkheads, floors, and partitions
1970; Amdt. 25-91, 62 FR 40704, July 29, 1997]
Section 25.365 Pressurized
(e) Any structure, component or part,
12:50 Apr 30, 2019

Page 51 -   PAGE

Section 25.391
(e) of this section. In addition, reasonable design precauti...
11, 1980; Amdt. 25-71, 55 FR 13477, Apr. 10,
1990; Amdt. 25-72, 55 FR 29776, July 20, 1990;
Section 25.367 Unsymmetrical loads due to
(a) The airplane must be designed for
(b) Pilot corrective action may be assumed to be initiated a...
Section 25.371
25.351, 25.473, 25.479, and 25.481, with the
Section 25.333(b)) is reached.
Section 25.373
(a) The airplane must be designed for
(b) If the device has automatic operating or load limiting f...
1990; Amdt. 25-86, 61 FR 5222, Feb. 9, 1996;
Section 25.391 Control surface loads: General.
25.341(a) and (b), 25.349, and 25.351, considering the requi...
(a) Loads parallel to hinge line, in
Section 25.393;
(b) Pilot effort effects, in Section 25.397;
(c) Trim tab effects, in Section 25.407;
(d) Unsymmetrical loads, in Section 25.427;
...

Page 52 -   PAGE

Section 25.393
14 CFR Ch. I (1-1-19 Edition)
(e) Auxiliary aerodynamic surfaces,
1996; Amdt. 25-141, 79 FR 73468, Dec. 11, 2014]
Section 25.393 Loads parallel to hinge line.
(a) Control surfaces and supporting
(b) In the absence of more rational
Section 25.395 Control system.
(a) Longitudinal, lateral, directional,
(b) The system limit loads of paragraph (a) of this section ...
(c) The loads must not be less than
Section 25.397(c).
1970; Amdt. 25-72, 55 FR 29776, July 20, 1990;
Section 25.397 Control system loads.
(a) General. The maximum and minimum pilot forces, specified...
(b) Pilot effort effects. In the control
(c) Limit pilot forces and torques. The
100 lbs ............
80 D in.-lbs 2 ...
40 lbs.
40 D in.-lbs.
...

Page 53 -   PAGE

Section 25.415
(b) The control system and surface
133 in.-lbs.
Section 25.407
(a) For elevator trim tabs, those required to trim the airpl...
(b) For aileron and rudder trim tabs,
Section 25.409
(a) Trim tabs. Trim tabs must be designed to withstand loads...
Section 25.397(b).
(b) Balancing tabs. Balancing tabs
(c) Servo tabs. Servo tabs must be designed for deflections ...
Section 25.415
(a) The flight control systems and
(c) The hinge moment factor K for
0.75
0.75
0.75
(d) The computed hinge moment of
(e) Where control system flexibility
12:50 Apr 30, 2019
...

Page 54 -   PAGE

Section 25.427
14 CFR Ch. I (1-1-19 Edition)
(f) For the condition of the control
(g) For the condition of taxiing with
(i) The loads corresponding to the
Section 25.427
(a) In designing the airplane for lateral gust, yaw maneuver...
(b) The horizontal tail must be assumed to be subjected to u...
(c) For empennage arrangements
Section 25.341(a) acting in any orientation at
(d) Unsymmetrical loading on the
Section 25.445 Auxiliary
(a) When significant, the aerodynamic influence between auxi...
Section 25.341(a) acting at any orientation at
(b) To provide for unsymmetrical
Section 25.391 must also be applied as follows:
1996]
Section 25.457
Section 25.345, accounting for the loads occurring during tr...
12:50 Apr 30, 2019
...

Page 55 -   PAGE

Section 25.459
Section 25.479
1990]
Section 25.471
(a) Loads and equilibrium. For limit
(b) Critical centers of gravity. The critical centers of gra...
c.g. results from random passenger or
Section 25.1583(c)(1) to ensure that the lateral
(c) Landing gear dimension data. Figure 1 of appendix A cont...
Section 25.473 Landing load conditions and
(a) For the landing conditions specified in Section 25.479 t...
(b) Airplane lift, not exceeding airplane weight, may be ass...
(c) The method of analysis of airplane and landing gear load...
(d) The landing gear dynamic characteristics must be validat...
(e) The coefficient of friction between
25-91, 62 FR 45481, Aug. 27, 1997; Amdt. 25-103,
66 FR 27394, May 16, 2001]
Section 25.477 Landing gear arrangement.
Section 25.479 Level landing conditions.
(a) In the level attitude, the airplane
12:50 Apr 30, 2019
...

Page 56 -   PAGE

Section 25.481
14 CFR Ch. I (1-1-19 Edition)
(b) For the level landing attitude for
(c) For the level landing attitude for
(d) In addition to the loading conditions prescribed in para...
25% of this maximum vertical ground
(i) A vertical load equal to 75% of the
25% respectively of that vertical load.
Section 25.473(a)(2). This load case need not be
25-91, 62 FR 45481, Aug. 27, 1997]
Section 25.481
(a) In the tail-down attitude, the airplane is assumed to co...
(b) For the tail-down landing condition for airplanes with t...
(c) For the tail-down landing condition for airplanes with n...
3 of appendix A, whichever is less.
1997; Amdt. 25-94, 63 FR 8848, Feb. 23, 1998]
Section 25.483
12:50 Apr 30, 2019

Page 57 -   PAGE

Section 25.493
(a) The ground reactions must be the
(b) Each unbalanced external load
1997]
Section 25.485
(a) For the side load condition, the
(b) Side loads of 0.8 of the vertical reaction (on one side)...
0.6 of the vertical reaction (on the
1997]
Section 25.487
(a) The landing gear and its supporting structure must be in...
(b) With the landing gear fully extended and not in contact ...
Section 25.489
1970]
Section 25.491
Section 25.493
(a) An airplane with a tail wheel is
0.8, must be combined with the vertical
(b) For an airplane with a nose wheel
(c) A drag reaction lower than that
12:50 Apr 30, 2019
...

Page 58 -   PAGE

Section 25.495
14 CFR Ch. I (1-1-19 Edition)
Section = Coefficient of friction of 0.80.
1970; Amdt. 25-97, 63 FR 29072, May 27, 1998]
Section 25.497 Tail-wheel yawing.
(a) A vertical ground reaction equal
(b) If there is a swivel, the tail wheel
(c) If there is a lock, steering device,
Section 25.499 Nose-wheel yaw and steering.
(a) A vertical load factor of 1.0 at the
(b) With the airplane assumed to be
(c) If the loads prescribed in paragraph (b) of this section...
12:50 Apr 30, 2019
Section 25.495 Turning.
(d) An airplane equipped with a nose
(e) In the absence of a more rational

Page 59 -   PAGE

Section 25.509
(d) For other than the nose gear, its
(b) of this section, except that - 
Section 25.493(b).
(e) With the airplane at design ramp
1970; Amdt. 25-46, 43 FR 50595, Oct. 30, 1978;
Section 25.503 Pivoting.
(a) The airplane is assumed to pivot
(b) The airplane is assumed to be in
Section 25.507 Reversed braking.
(a) The airplane must be in a three
(b) For airplanes with nose wheels,
(c) For airplanes with tail wheels, the
Section 25.509
(a) The towing loads specified in
(i) 0.3 WT for WT less than 30,000
30,000 and 100,000 pounds; and
(b) For towing points not on the
(c) The towing loads specified in
(i) A reaction with a maximum value
(d) The prescribed towing loads are as
...

Page 60 -   PAGE

Section 25.511
14 CFR Ch. I (1-1-19 Edition)
0.75 FTOW per main
1.0 FTOW ...................
0.5 FTOW ...................
Section 25.511 Ground load: unsymmetrical
(a) General. Multiple-wheel landing
(b) Distribution of limit loads to wheels;
(c) Deflated tires. The effect of deflated tires on the stru...
...

Page 61 -   PAGE

Section 25.523
(e) Taxiing and ground handling conditions. For one and for ...
Section 25.493 (a) and (b)(2), the drag loads on
(f) Towing conditions. For one and for
Section 25.519 Jacking and tie-down provisions.
(a) General. The airplane must be designed to withstand the ...
(b) Jacking. The airplane must have
0.33 times the vertical static reaction
(i) The airplane structure must be designed for a vertical l...
(c) Tie-down. If tie-down points are
Section 25.521
(a) Seaplanes must be designed for
(b) Unless a more rational analysis of
(c) The requirements of this section
Section 25.523 Design weights and center of
(a) Design weights. The water load requirements must be met ...
(b) Center of gravity positions. The
12:50 Apr 30, 2019

Page 62 -   PAGE

Section 25.525
14 CFR Ch. I (1-1-19 Edition)
Section 25.525
(a) Unless otherwise prescribed, the
(b) In applying the loads resulting
Section 25.527, the loads may be distributed
(c) For twin float seaplanes, each
(d) Except in the takeoff condition of
Section 25.531, the aerodynamic lift on the
Section 25.527 Hull and main float load factors.
(a) Water reaction load factors nW
1 + rx 2
(b) The following values are used:
1970]
Section 25.529 Hull and main float landing
(a) Symmetrical step, bow, and stern
12:50 Apr 30, 2019
...

Page 63 -   PAGE

Section 25.533
Section 25.533 Hull and main float bottom
(a) General. The hull and main float
(b) Local pressures. For the design of
12:50 Apr 30, 2019
(a) The aerodynamic wing lift is assumed to be zero; and
(b) A downward inertia load, corresponding to a load factor ...
1970]
Section 25.531 Hull and main float takeoff
(b) Unsymmetrical landing for hull and
0.75 and 0.25 tan b times the resultant
(c) Unsymmetrical landing; twin float
0.25 tan b at one float times the step

Page 64 -   PAGE

Section 25.535
14 CFR Ch. I (1-1-19 Edition)
(c) Distributed pressures. For the design of the frames, kee...
1970]
Section 25.535 Auxiliary float loads.
(a) General. Auxiliary floats and their
2 3
(c) Bow loading. The resultant limit
(d) Unsymmetrical step loading. The resultant water load con...
(b) of this section. The side load must
12:50 Apr 30, 2019
Section 25.527);
(b) Step loading. The resultant water

Page 65 -   PAGE

Section 25.561
(e) Unsymmetrical bow loading. The resultant water load cons...
(c) of this section. The side load must
(f) Immersed float condition. The resultant load must be app...
0 
(g) Float bottom pressures. The float
1970]
12:50 Apr 30, 2019
Section 25.537
Section 25.561 General.
(a) The airplane, although it may be
(b) The structure must be designed to
(i) Upward, 3.0g
...

Page 66 -   PAGE

Section 25.562
14 CFR Ch. I (1-1-19 Edition)
1970; Amdt. 25-64, 53 FR 17646, May 17, 1988;
Section 25.562 Emergency landing dynamic
(a) The seat and restraint system in
(b) Each seat type design approved
170-pound
0.08 seconds after impact and must
(c) The following performance measures must not be exceeded ...
2,000 pounds.
12:50 Apr 30, 2019
2 .5

Page 67 -   PAGE

Section 25.571
(t) is in seconds, and (a) is in units of gravity
(g).
(b)(2) of this section to the extent they
Section 25.563 Structural
Section 25.571 Damage - tolerance and
(a) General. An evaluation of the
(b) and (e) of this section, except as
(i) The typical loading spectra, temperatures, and humiditie...
(i) Single load path structure, and
(b) Damage-tolerance evaluation. The
12:50 Apr 30, 2019

Page 68 -   PAGE

Section 25.571
14 CFR Ch. I (1-1-19 Edition)
(i) The normal operating differential
(b)(1) through (4) of this section, if they
(c) Fatigue (safe-life) evaluation. Compliance with the dama...
(d) Sonic fatigue strength. It must be
(b) of this section are applied to all
(e) Damage-tolerance (discrete source)
12:50 Apr 30, 2019

Page 69 -   PAGE

Section 25.607
11, 1980; Amdt. 25-72, 55 FR 29776, July 20,
1990; Amdt. 25-86, 61 FR 5222, Feb. 9, 1996;
23338, Apr. 28, 1998; Amdt. 25-132, 75 FR 69781,
Section 25.581 Lightning protection.
(a) The airplane must be protected
(b) For metallic components, compliance with paragraph (a) o...
(c) For nonmetallic components,
Subpart D - Design and
Section 25.601 General.
Section 25.603 Materials.
(a) Be established on the basis of experience or tests;
(b) Conform to approved specifications (such as industry or ...
(c) Take into account the effects of
1976; Amdt. 25-46, 43 FR 50595, Oct. 30, 1978]
Section 25.605
(a) The methods of fabrication used
(b) Each new aircraft fabrication
1978]
Section 25.607
(a) Each removable bolt, screw, nut,
...

Page 70 -   PAGE

Section 25.609
Section 25.609
14 CFR Ch. I (1-1-19 Edition)
(a) Be suitably protected against deterioration or loss of s...
(b) Have provisions for ventilation
Section 25.611
(a)Means must be provided to allow
(b) EWIS must meet the accessibility
2007]
Section 25.613 Material strength properties
(a) Material strength properties must
(b) Material design values must be
(c) The effects of environmental conditions, such as tempera...
(d) [Reserved]
(e) Greater material design values
(f) Other material design values may
1978; Amdt. 25-72, 55 FR 29776, July 20, 1990;
Section 25.619
Section 25.303 must be multiplied by the highest pertinent s...
(a) Uncertain;
(b) Likely to deteriorate in service
...

Page 71 -   PAGE

Section 25.621
(b) Bearing stresses and surfaces. The
(c) and (d) of this section - 
(c) Critical castings. Each casting
(i) It is demonstrated, in the form of
Section 25.305(a) and (b).
(i) Each casting receives:
Section 25.305(b) at an ultimate load corresponding to a cas...
Section 25.305(a) at a load of 1.15 times the
(i) Each casting receives:
Section 25.305(b) at an ultimate load corresponding to a cas...
Section 25.305(a) at a load of 1.15 times the
(d) Non-critical castings. For each
(i) Castings are manufactured to approved specifications tha...
12:50 Apr 30, 2019

Page 72 -   PAGE

Section 25.623
14 CFR Ch. I (1-1-19 Edition)
(i) Inspection of 100 percent of its surface, using visual i...
2014]
Section 25.623
(a) Except as provided in paragraph
(b) of this section, each part that has
(b) No bearing factor need be used for
Section 25.625
(a) For each fitting whose strength is
(b) No fitting factor need be used - 
(c) For each integral fitting, the part
(d) For each seat, berth, safety belt,
1970; Amdt. 25-72, 55 FR 29776, July 20, 1990]
Section 25.629 Aeroelastic stability requirements.
(a) General. The aeroelastic stability
(b) Aeroelastic stability envelopes. The
12:50 Apr 30, 2019

Page 73 -   PAGE

Section 25.629
Section 25.629(d) below, for all approved altitudes, any air...
(i) The VD/MD envelope determined by
Section 25.335(b); or,
(c) Balance weights. If concentrated
(d) Failures, malfunctions, and adverse
(d)(5) of this section need not be considered in showing com...
(i) The structural element could not
25.672, and 25.1309.
(e) Flight flutter testing. Full scale
12:50 Apr 30, 2019

Page 74 -   PAGE

Section 25.631
14 CFR Ch. I (1-1-19 Edition)
Section 25.631
Section 25.651
(a) Limit load tests of control surfaces are required. These...
(b) Compliance with the special factors requirements of Sect...
25.625 and 25.657 for control surface
Section 25.655
(a) Movable tail surfaces must be installed so that there is...
(b) If an adjustable stabilizer is used,
Section 25.657 Hinges.
(a) For control surface hinges, including ball, roller, and ...
6.67 must be used with respect to the
(b)
Section 25.671 General.
(a) Each control and control system
(b) Each element of each flight control system must be desig...
(c) The airplane must be shown by
12:50 Apr 30, 2019

Page 75 -   PAGE

Section 25.677
(d) The airplane must be designed so
1970]
Section 25.672 Stability augmentation and
(a) A warning which is clearly distinguishable to the pilot ...
(b) The design of the stability augmentation system or of an...
(c) It must be shown that after any
Section 25.675
(a) Each control system must have
(b) Each stop must be located so that
(c) Each stop must be able to withstand any loads correspond...
1976]
Section 25.677
(a) Trim controls must be designed to
(b) There must be means adjacent to
12:50 Apr 30, 2019

Page 76 -   PAGE

Section 25.679
14 CFR Ch. I (1-1-19 Edition)
(c) Trim control systems must be designed to prevent creepin...
(d) If an irreversible tab control system is used, the part ...
1970; Amdt. 25-115, 69 FR 40527, July 2, 2004]
Section 25.679
(a) There must be a device to prevent
(b) The device must have means to
Section 25.681
(a) Compliance with the limit load
(b) Compliance must be shown (by
Section 25.683
(a) It must be shown by operation
(b) It must be shown by analysis and,
(c) It must be shown that under vibration loads in the norma...
Section 25.685 Control system details.
(a) Each detail of each control system must be designed and ...
(b) There must be means in the cockpit to prevent the entry ...
(c) There must be means to prevent
(d) Sections 25.689 and 25.693 apply to
1976]
...

Page 77 -   PAGE

Section 25.701
(b) Each kind and size of pulley must
(c) Fairleads must be installed so
(d) Clevis pins subject to load or motion and retained only ...
(e) Turnbuckles must be attached to
(f) There must be provisions for visual inspection of fairle...
Section 25.693
Section 25.697 Lift and drag devices, controls.
(a) Each lift device control must be
(b) Each lift and drag device control
(c) The rate of motion of the surfaces
(d) The lift device control must be
9.0 (knots).
1978; Amdt. 25-57, 49 FR 6848, Feb. 23, 1984]
Section 25.699
(a) There must be means to indicate
(b) There must be means to indicate
(c) If any extension of the lift and
Section 25.701
(a) Unless the airplane has safe flight
(b) If a wing flap or slat interconnection or equivalent mea...
...

Page 78 -   PAGE

Section 25.703
14 CFR Ch. I (1-1-19 Edition)
(c) For airplanes with flaps or slats
(d) The interconnection must be designed for the loads resul...
Section 25.703
(a) The system must provide to the
(b) The warning required by paragraph (a) of this section mu...
(c) The means used to activate the
Section 25.721
(a) The landing gear system must be
20 percent of the vertical load or 20 percent of the drag lo...
(b) The airplane must be designed to
(i) With the landing gear fully retracted; and
(i) The landing gear fully retracted
(c) For configurations where the engine nacelle is likely to...
Section 25.723 Shock absorption tests.
(a) The analytical representation of
12:50 Apr 30, 2019

Page 79 -   PAGE

Section 25.729
Section 25.473.
(b) The landing gear may not fail in
(c) In lieu of the tests prescribed in
Section 25.729
(a) General. For airplanes with retractable landing gear, th...
(i) The loads occurring in the flight
0.67 VC.
(b) Landing gear lock. There must be
(c) Emergency operation. There must
(d) Operation test. The proper functioning of the retracting...
(e) Position indicator and warning device. If a retractable ...
12:50 Apr 30, 2019

Page 80 -   PAGE

Section 25.731
14 CFR Ch. I (1-1-19 Edition)
(f) Protection of equipment on landing
1970; Amdt. 25-42, 43 FR 2323, Jan. 16, 1978;
25-75, 56 FR 63762, Dec. 5, 1991; Amdt. 25-136,
77 FR 1617, Jan. 11, 2012]
Section 25.731 Wheels.
(a) Each main and nose wheel must
(b) The maximum static load rating
(c) The maximum limit load rating of
(d) Overpressure burst prevention.
(e) Braked wheels. Each braked wheel
1990; Amdt. 25-107, 67 FR 20420, Apr. 24, 2002]
Section 25.733
(a) When a landing gear axle is fitted
(b) The applicable ground reactions
12:50 Apr 30, 2019

Page 81 -   PAGE

Section 25.735
(c) When a landing gear axle is fitted
(a)(2), (b)(1), (b)(2), and (b)(3) of this
(d) Each tire installed on a retractable landing gear system...
(e) For an airplane with a maximum
25-72, 55 FR 29777, July 20, 1990, as amended
Section 25.735
(a) Approval. Each assembly consisting of a wheel(s) and bra...
(b) Brake system capability. The brake
(c) Brake controls. The brake controls
(i) Arm and disarm the system, and
(d) Parking brake. The airplane must
(e) Antiskid system. If an antiskid system is installed:
12:50 Apr 30, 2019

Page 82 -   PAGE

Section 25.737
14 CFR Ch. I (1-1-19 Edition)
(f) Kinetic energy capacity - (1) Design
(g) Brake condition after high kinetic
3 minutes, it must be demonstrated
(h) Stored energy systems. An indication to the flightcrew o...
(i) Brake wear indicators. Means must
(j) Overtemperature burst prevention.
(k) Compatibility. Compatibility of
2002, as amended by Amdt. 25-108, 67 FR
70827, Nov. 26, 2002; 68 FR 1955, Jan. 15, 2003]
Section 25.737
12:50 Apr 30, 2019

Page 83 -   PAGE

Section 25.773
Section 25.751 Main float buoyancy.
(a) A buoyancy of 80 percent in excess
(b) Not less than five watertight compartments approximately...
Section 25.753 Main float design.
Section 25.521.
Section 25.755 Hulls.
(a) Each hull must have enough watertight compartments so th...
(b) Bulkheads with watertight doors
Section 25.771 Pilot compartment.
(a) Each pilot compartment and its
(b) The primary controls listed in
Section 25.779(a), excluding cables and control
(c) If provision is made for a second
(d) The pilot compartment must be
(e) Vibration and noise characteristics of cockpit equipment...
1965]
Section 25.772
(a) For airplanes with a maximum
(b) Means must be provided to enable
(c) There must be an emergency
...

Page 84 -   PAGE

Section 25.773
14 CFR Ch. I (1-1-19 Edition)
(b) Precipitation conditions. For precipitation conditions, ...
(i) Heavy rain at speeds up to 1.5 VSR1
(i) Is openable under the conditions
(i) Any system failure or combination of failures which is n...
Section 25.1309, under the precipitation conditions specifie...
(c) Internal windshield and window
(d) Fixed markers or other guides
(e) Vision systems with transparent displays. A vision syste...
12:50 Apr 30, 2019

Page 85 -   PAGE

Section 25.777
1970; Amdt. 25-46, 43 FR 50595, Oct. 30, 1978;
25-108, 67 FR 70827, Nov. 26, 2002; Amdt. 25-
121, 72 FR 44669, Aug. 8, 2007; Amdt. 25-136, 77
65525, Nov. 4, 2014; Docket FAA-2013-0485,
Section 25.775 Windshields and windows.
(a) Internal panes must be made of
(b) Windshield panes directly in front
(c) Unless it can be shown by analysis
(d) The design of windshields and
(e) The windshield panels in front of
1970; Amdt. 25-38, 41 FR 55466, Dec. 20, 1976]
Section 25.777 Cockpit controls.
(a) Each cockpit control must be located to provide convenie...
(b) The direction of movement of
(c) The controls must be located and
Section 25.1523) when any member of this
(d) Identical powerplant controls for
12:50 Apr 30, 2019

Page 86 -   PAGE

Section 25.779
14 CFR Ch. I (1-1-19 Edition)
(e) Wing flap controls and other auxiliary lift device contr...
(f) The landing gear control must be
(g) Control knobs must be shaped in
(h) If a flight engineer is required as
(b) Powerplant and auxiliary controls:
1978]
Section 25.779 Motion and effect of cockpit
(a) Aerodynamic controls:
Section 25.781
1990]
12:50 Apr 30, 2019

Page 87 -   PAGE

Section 25.783
(a) General. This section applies to fuselage doors, which i...
12:50 Apr 30, 2019
Section 25.783

Page 88 -   PAGE

Section 25.783
14 CFR Ch. I (1-1-19 Edition)
Section 25.607.
Section 25.807(h), must also meet the applicable requirement...
25.812 for emergency exits.
(b) Opening by persons. There must be
(c) Pressurization prevention means.
(i) With failures or malfunctions in
(d) Latching and locking. The latching
(i) Have an individual lock for each
12:50 Apr 30, 2019

Page 89 -   PAGE

Section 25.783
(i) The maximum operator effort
(e) Warning, caution, and advisory indications. Doors must b...
(i) Each door that is subject to pressurization and for whic...
(f) Visual inspection provision. Each
(g) Certain maintenance doors, removable emergency exits, an...
(c) and (f) of this section.
(h) Doors that are not a hazard. For
12:50 Apr 30, 2019

Page 90 -   PAGE

Section 25.785
14 CFR Ch. I (1-1-19 Edition)
Section 25.785 Seats, berths, safety belts, and
(a) A seat (or berth for a nonambulant person) must be provi...
(b) Each seat, berth, safety belt, harness, and adjacent par...
(c) Each seat or berth must be approved.
(d) Each occupant of a seat that
(e) Each berth must be designed so
(f) Each seat or berth, and its supporting structure, and ea...
Section 25.561 must be multiplied by a factor
(g) Each seat at a flight deck station
12:50 Apr 30, 2019

Page 91 -   PAGE

Section 25.787
(h) Each seat located in the passenger compartment and desig...
(i) Each safety belt must be equipped
(j) If the seat backs do not provide a
(k) Each projecting object that would
(l) Each forward observer-s seat required by the operating r...
1996]
Section 25.787
(a) Each compartment for the stowage of cargo, baggage, carr...
Section 25.561(b)(3) for which the breaking
10 seats or more, each stowage compartment in the passenger ...
(b) There must be a means to prevent
(c) If cargo compartment lamps are
1972; Amdt. 25-38, 41 FR 55466, Dec. 20, 1976;
25-139, 79 FR 59430, Oct. 2, 2014]
12:50 Apr 30, 2019

Page 92 -   PAGE

Section 25.789
14 CFR Ch. I (1-1-19 Edition)
Section 25.789 Retention of items of mass in
(e) Symbols that clearly express the
(a) Means must be provided to prevent each item of mass (tha...
Section 25.561(b).
(b) Each interphone restraint system
Section 25.561(b)(3), the interphone will remain in its stow...
1978]
Section 25.791 Passenger information signs
(a) If smoking is to be prohibited,
(b) Signs that notify when seat belts
(c) A placard must be located on or
(d) Lavatories must have  - No Smoking -  or  - No Smoking i...
Section 25.793
Section 25.795
(a) Protection of flightcrew compartment. If a flightdeck do...
(b) Airplanes with a maximum certificated passenger seating ...
0.59% carbon monoxide and 1.23% carbon dioxide.
12:50 Apr 30, 2019
...

Page 93 -   PAGE

Section 25.795
(i) Impact or damage from a 0.5-inch
430 feet per second (131.1 meters per
(c) An airplane with a maximum certificated passenger seatin...
12:50 Apr 30, 2019
(c)(2)(i) of this section is impracticable,
(i) Areas above the overhead bins
(d) Each chemical oxygen generator
(d)(3) of this section that the Administrator finds provides...
(e) Exceptions. Airplanes used solely
(b)(3), and (c)(2) of this section.
(f) Material Incorporated by Reference.

Page 94 -   PAGE

Section 25.801
14 CFR Ch. I (1-1-19 Edition)
552(a) and 1 CFR part 51.
(i) National Institute of Justice
2008, as amended at 74 FR 22819, May 15, 2009;
Section 25.801
(a) If certification with ditching provisions is requested, ...
(b) Each practicable design measure,
(c) The probable behavior of the airplane in a water landing...
(d) It must be shown that, under reasonably probable water c...
(e) Unless the effects of the collapse
1990]
Section 25.803
(a) Each crew and passenger area
(b) [Reserved]
(c) For airplanes having a seating capacity of more than 44 ...
(d)-(e) [Reserved]
Section 25.807
(a) Type. For the purpose of this part,
12:50 Apr 30, 2019
...

Page 95 -   PAGE

Section 25.807
(b) Step down distance. Step down distance, as used in this ...
(c) Over-sized exits. Openings larger
(d) Asymmetry. Exits of an exit pair
(e) Uniformity. Exits must be distributed as uniformly as pr...
(f) Location. (1) Each required passenger emergency exit mus...
12:50 Apr 30, 2019

Page 96 -   PAGE

Section 25.807
14 CFR Ch. I (1-1-19 Edition)
(g) Type and number required. The
(g)(9) of this section, the maximum
(i) For a ventral exit, 12 additional
(h) Other exits. The following exits
(i) Ditching emergency exits for passengers. Whether or not ...
12:50 Apr 30, 2019

Page 97 -   PAGE

Section 25.809
(j) Flightcrew emergency exits. For airplanes in which the p...
1996; 62 FR 1817, Jan. 13, 1997; Amdt. 25-94, 63
1998; Amdt. 25-114, 69 FR 24502, May 3, 2004]
Section 25.809 Emergency exit arrangement.
(a) Each emergency exit, including
(b) Each emergency exit must be
(c) The means of opening emergency
(d) If a single power-boost or single
12:50 Apr 30, 2019

Page 98 -   PAGE

Section 25.810
14 CFR Ch. I (1-1-19 Edition)
(e) Each emergency exit must be
(f) Each door must be located where
(g) There must be provisions to minimize the probability of ...
(h) When required by the operating
(i) Each emergency exit must have a
20, 1967; Amdt. 25-32, 37 FR 3970, Feb. 24, 1972;
25-46, 43 FR 50597, Oct. 30, 1978; Amdt. 25-47,
44 FR 61325, Oct. 25, 1979; Amdt. 25-72, 55 FR
29782, July 20, 1990; Amdt. 25-114, 69 FR 24502,
2004]
Section 25.810 Emergency
(a) Each non over-wing Type A, Type
(i) It must be automatically deployed
25-knot winds directed from the most
(v) For each system installation
12:50 Apr 30, 2019

Page 99 -   PAGE

Section 25.811
(i) Attached to the fuselage structure
(b) Assist means from the cabin to
(c) An escape route must be established from each overwing e...
(d) Means must be provided to assist
(e) If an integral stair is installed in
Section 25.561(b)(3), acting separately relative
1996; 62 FR 1817, Jan. 13, 1997; Amdt. 25-114, 69
Section 25.811 Emergency exit marking.
(a) Each passenger emergency exit,
12:50 Apr 30, 2019

Page 100 -   PAGE

Section 25.811
14 CFR Ch. I (1-1-19 Edition)
(b) The identity and location of each
(c) Means must be provided to assist
(d) The location of each passenger
(e) The location of the operating handle and instructions fo...
30 inches.
(i) Be self-illuminated with an initial
(i) With a red arrow, with a shaft at
(f) Each emergency exit that is required to be openable from...
(g) Each sign required by paragraph
(d) of this section may use the word
1972; Amdt. 25-46, 43 FR 50597, Oct. 30, 1978; 43
45229, Aug. 26, 1993; Amdt. 25-88, 61 FR 57958,
12:50 Apr 30, 2019

Page 101 -   PAGE

Section 25.812
Section 25.812 Emergency lighting.
(a) An emergency lighting system,
(b) Emergency exit signs - 
(i) Each passenger emergency exit locator sign required by S...
(c) General illumination in the passenger cabin must be prov...
(d) The floor of the passageway leading to each floor-level ...
(e) Floor proximity emergency escape path marking must provi...
(f) Except for subsystems provided in
12:50 Apr 30, 2019

Page 102 -   PAGE

Section 25.812
14 CFR Ch. I (1-1-19 Edition)
(g) Exterior emergency lighting must
(i) Not less than 0.03 foot-candle
(h)
(i) May not be adversely affected by
(i) The energy supply to each emergency lighting unit must p...
(j) If storage batteries are used as the
(k) Components of the emergency
12:50 Apr 30, 2019

Page 103 -   PAGE

Section 25.813
(l) The emergency lighting system
1971; Amdt. 25-32, 37 FR 3971, Feb. 24, 1972;
25-58, 49 FR 43186, Oct. 26, 1984; Amdt. 25-88,
61 FR 57958, Nov. 8, 1996; Amdt. 25-116, 69 FR
62788, Oct. 27, 2004; Amdt. 25-128, 74 FR 25645,
Section 25.813
(a) There must be a passageway leading from the nearest main...
(b) Adequate space to allow crewmember(s) to assist in the e...
Section 25.810(a).
12:50 Apr 30, 2019

Page 104 -   PAGE

Section 25.813
14 CFR Ch. I (1-1-19 Edition)
(i) While manually activating the assist means (where applic...
(c) The following must be provided
(i) Except as provided in paragraph
(c)(1)(ii), the access must be provided
(i) For airplanes that have a passenger seating configuratio...
(i) Are readable by all persons seated
(d) If it is necessary to pass through
(e) No door may be installed between
(f) If it is necessary to pass through a
12:50 Apr 30, 2019

Page 105 -   PAGE

Section 25.819
20, 1967; Amdt. 25-32, 37 FR 3971, Feb. 24, 1972;
25-72, 55 FR 29783, July 20, 1990; Amdt. 25-76,
57 FR 19244, May 4, 1992; Amdt. 25-76, 57 FR
29120, June 30, 1992; Amdt. 25-88, 61 FR 57958,
27, 2004; Amdt. 25-128, 74 FR 25645, May 29,
2009]
Section 25.815 Width of aisle.
10 or less .......................................
11 through 19 ................................
20 or more .....................................
25 in. from
25 in. and
1 12
1 A narrower width not less than 9 inches may be approved
1976]
...

Page 106 -   PAGE

Section 25.820
14 CFR Ch. I (1-1-19 Edition)
43154, June 26, 1980; Amdt. 25-110; 68 FR 36883,
Section 25.820 Lavatory doors.
Section 25.831 Ventilation.
(a) Under normal operating conditions and in the event of an...
(b) Crew and passenger compartment
0.5 percent by volume (sea level equivalent) in compartments...
(c) There must be provisions made to
(d) If accumulation of hazardous
(e) Except as provided in paragraph
(f) of this section, means must be provided to enable the oc...
(f) Means to enable the flight crew to
800 cubic feet or less.
(g) The exposure time at any given
12:50 Apr 30, 2019

Page 107 -   PAGE

Section 25.841
Section 25.833
(a) The airplane cabin ozone concentration during flight mus...
(b) For the purpose of this section,
(c) Compliance with this section
1982; Amdt. 25-94, 63 FR 8848, Feb. 23, 1998]
Section 25.841
(a) Pressurized cabins and compartments to be occupied must ...
(i) Twenty-five thousand (25,000) feet
12:50 Apr 30, 2019
Section 25.832

Page 108 -   PAGE

Section 25.843
14 CFR Ch. I (1-1-19 Edition)
(b) Pressurized cabins must have at
(b)(5) and (b)(6) of this section and
Section 25.1447(c), must be located and the
1976; Amdt. 25-87, 61 FR 28696, June 5, 1996]
Section 25.843
(a) Strength test. The complete pressurized cabin, including...
(b) Functional tests. The following
Section 25.851
(a) Hand fire extinguishers. (1) The following minimum numbe...
12:50 Apr 30, 2019

Page 109 -   PAGE

Section 25.853
7 through 30 ...............................
31 through 60 .............................
61 through 200 ...........................
201 through 300 ............................
301 through 400 ............................
401 through 500 ............................
501 through 600 ............................
601 through 700 ............................
(b) Built-in fire extinguishers. If a
(i) No extinguishing agent likely to
Section 25.853 Compartment interiors.
...

Page 110 -   PAGE

Section 25.854
14 CFR Ch. I (1-1-19 Edition)
(e) The interiors of compartments,
(f) Smoking is not allowed in lavatories. If smoking is allo...
(g) Regardless of whether smoking is
(h) Each receptacle used for the disposal of flammable waste...
27, 2004]
Section 25.854 Lavatory fire protection.
(a) Each lavatory must be equipped
(b) Each lavatory must be equipped
Section 25.855 Cargo or baggage compartments.
(a) The compartment must meet one
(b) Each of the following cargo or
Section 25.857, must have a liner that is separate from, but...
(c) Ceiling and sidewall liner panels
(d) All other materials used in the
(e) No compartment may contain any
(f) There must be means to prevent
12:50 Apr 30, 2019

Page 111 -   PAGE

Section 25.857
(g) Sources of heat within the compartment must be shielded ...
(h) Flight tests must be conducted to
Section 25.857 concerning - 
(i) During the above tests, it must be
(j) Cargo or baggage compartment
1998; Amdt. 25-116, 69 FR 62788, Oct. 27, 2004;
Section 25.856 Thermal/Acoustic
(a) Thermal/acoustic insulation material installed in the fu...
(b) For airplanes with a passenger capacity of 20 or greater...
Section 25.857 Cargo compartment classification.
(a) Class A; A Class A cargo or baggage compartment is one i...
(b) Class B. A Class B cargo or baggage compartment is one i...
(c) Class C. A Class C cargo or baggage compartment is one n...
(d) [Reserved]
(e) Class E. A Class E cargo compartment is one on airplanes...
12:50 Apr 30, 2019

Page 112 -   PAGE

Section 25.858
14 CFR Ch. I (1-1-19 Edition)
(f) Class F. A Class F cargo or baggage compartment must be ...
1972; Amdt. 25-60, 51 FR 18243, May 16, 1986;
Section 25.858 Cargo or baggage compartment smoke or fire de...
(a) The detection system must provide a visual indication to...
(b) The system must be capable of detecting a fire at a temp...
(c) There must be means to allow the
(d) The effectiveness of the detection
1998]
Section 25.859 Combustion heater fire protection.
(a) Combustion heater fire zones. The
(i) Be damaged by heater malfunctioning; or
(b) Ventilating air ducts. Each ventilating air duct passing...
(c) Combustion air ducts. Each combustion air duct must be f...
12:50 Apr 30, 2019

Page 113 -   PAGE

Section 25.863
(d) Heater controls; general. Provision
(e) Heater safety controls. For each
(i) The heat exchanger temperature
(i) Be independent of components
(f) Air intakes. Each combustion and
(g) Heater exhaust. Heater exhaust
(h) Heater fuel systems. Each heater
(i) Drains. There must be means to
1967; Amdt. 25-23, 35 FR 5676, Apr. 8, 1970]
Section 25.863 Flammable fluid fire protection.
(a) In each area where flammable
(b) Compliance with paragraph (a) of
12:50 Apr 30, 2019

Page 114 -   PAGE

Section 25.865
14 CFR Ch. I (1-1-19 Edition)
(c) If action by the flight crew is required to prevent or c...
(d) Each area where flammable fluids
1978]
Section 25.865 Fire protection of flight controls, engine mo...
(a) Surfaces to the rear of the nacelles, within one nacelle...
(b) Paragraph (a) of this section does
16, 2004; Amdt. 25-123, 72 FR 63405, Nov. 8,
2007]
Section 25.871
Section 25.867 Fire protection: other components.
Section 25.869
(b) Each vacuum air system line and
(c) Oxygen equipment and lines
(a) Electrical system components:
Section 25.875 Reinforcement
(a) Each part of the airplane near the
(b) No window may be near the propeller tips unless it can w...
12:50 Apr 30, 2019
...

Page 115 -   PAGE

Section 25.903
Section 25.899 Electrical bonding and protection against sta...
(a) Electrical bonding and protection
(b) Compliance with paragraph (a) of
Subpart E - Powerplant
Section 25.901 Installation.
(a) For the purpose of this part, the
(b) For each powerplant - 
(i) The installation instructions provided under SectionSect...
(c) For each powerplant and auxiliary
(d) Each auxiliary power unit installation must meet the app...
1970; Amdt. 25-40, 42 FR 15042, Mar. 17, 1977;
25-126, 73 FR 63345, Oct. 24, 2008]
Section 25.903
(a) Engine type certificate. (1) Each engine must have a typ...
(i) Sections 33.76, 33.77 and 33.78 of
2000, or as subsequently amended; or
30, 1998, unless that engine-s foreign object ingestion serv...
1 to 59, Revised as of January 1, 1975. See 39
(i) Section 33.68 of this chapter in effect on January 5, 20...
2015, unless that engine-s ice accumulation service history ...
...

Page 116 -   PAGE

Section 25.904
14 CFR Ch. I (1-1-19 Edition)
1984, unless that engine-s ice accumulation service history ...
(b) Engine isolation. The powerplants
(c) Control of engine rotation. There
(d) Turbine engine installations. For
(e) Restart capability. (1) Means to restart any engine in f...
(f) Auxiliary Power Unit. Each auxiliary power unit must be ...
1970; Amdt. 25-40, 42 FR 15042, Mar. 17, 1977;
25-72, 55 FR 29784, July 20, 1990; Amdt. 25-73,
55 FR 32861, Aug. 10, 1990; Amdt. 25-94, 63 FR
8848, Feb. 23, 1998; Amdt. 25-95, 63 FR 14798,
14, 2000; Amdt. 25-140, 79 FR 65525, Nov. 4,
2014]
Section 25.904 Automatic takeoff thrust control system (ATTC...
Section 25.905
(a) Each propeller must have a type
(b) Engine power and propeller shaft
(c) The propeller blade pitch control
(d) Design precautions must be taken
12:50 Apr 30, 2019
...

Page 117 -   PAGE

Section 25.929
11, 1980; Amdt. 25-57, 49 FR 6848, Feb. 23, 1984;
25-126, 73 FR 63345, Oct. 24, 2008]
Section 25.907 Propeller
(a) The applicant must determine the
(b) The applicant must demonstrate
(c) The applicant must perform an
Section 25.925
(a) Ground clearance. There must be a
(b) Water clearance. There must be a
(c) Structural clearance. There must
1990]
Section 25.929 Propeller deicing.
(a) If certification for flight in icing
12:50 Apr 30, 2019

Page 118 -   PAGE

Section 25.933
14 CFR Ch. I (1-1-19 Edition)
(b) If combustible fluid is used for
25.1185 and 25.1189 apply.
2014]
Section 25.933 Reversing systems.
(a) For turbojet reversing systems - 
(i) Each operable reverser can be restored to the forward th...
(b) For propeller reversing systems - 
Section 25.934 Turbojet engine thrust reverser system tests.
Section 25.937 Turbopropeller-drag limiting
Section 25.939 Turbine
(a) Turbine engine operating characteristics must be investi...
(b) [Reserved]
(c) The turbine engine air inlet system may not, as a result...
1977]
12:50 Apr 30, 2019

Page 119 -   PAGE

Section 25.941 Inlet, engine,
Section 25.951
(a) The system comprised of the
(b) The dynamic effects of the operation of these (including...
(c) In showing compliance with paragraph (b) of this section...
(e) and (f) of Section 25.143.
2007]
Section 25.943
Section 25.945 Thrust or power augmentation
(a) General. Each fluid injection system must provide a flow...
(b) Fluid tanks. Each augmentation
(c) Augmentation system drains
(d) The augmentation liquid tank capacity available for the ...
(e) This section does not apply to fuel
1990; Amdt. 25-115, 69 FR 40527, July 2, 2004]
Section 25.951 General.
(a) Each fuel system must be constructed and arranged to ens...
12:50 Apr 30, 2019

Page 120 -   PAGE

Section 25.952
14 CFR Ch. I (1-1-19 Edition)
(b) Each fuel system must be arranged so that any air which ...
20 seconds for reciprocating engines; or
(c) Each fuel system for a turbine engine must be capable of...
(d) Each fuel system for a turbine engine powered airplane m...
1970; Amdt. 25-36, 39 FR 35460, Oct. 1, 1974;
25-73, 55 FR 32861, Aug. 10, 1990]
Section 25.952 Fuel system analysis and test.
(a) Proper fuel system functioning
(b) The likely failure of any heat exchanger using fuel as o...
Section 25.953 Fuel system independence.
(a) Allowing the supply of fuel to
(b) Any other acceptable method.
Section 25.954 Fuel system lightning protection.
(a) For purposes of this section - 
(b) The design and installation of a
(c) To comply with paragraph (b) of
(d) To protect design features that
Section 25.1529.
47556, Sept. 20, 2018]
...

Page 121 -   PAGE

Section 25.961
(b) If an engine can be supplied with
1967]
Section 25.957 Flow between interconnected
Section 25.959 Unusable fuel supply.
1977]
Section 25.961 Fuel system hot weather operation.
(a) The fuel system must perform
(i) For reciprocating engine powered
12:50 Apr 30, 2019

Page 122 -   PAGE

Section 25.963
14 CFR Ch. I (1-1-19 Edition)
(b) The test prescribed in paragraph
(a) of this section may be performed in
1984]
Section 25.963
(a) Each fuel tank must be able to
(b) Flexible fuel tank liners must be
(c) Integral fuel tanks must have facilities for interior in...
(d) Fuel tanks must, so far as it is
(i) The fuel pressures resulting from
1.5g may be used in lieu of 3.0g as specified in Section 25....
Section 25.561(b)(3) considering a fuel volume
3.0g as specified in Section 25.561(b)(3).
12:50 Apr 30, 2019

Page 123 -   PAGE

Section 25.965
(e) Fuel tank access covers must
(f) For pressurized fuel tanks, a
1977; Amdt. 25-69, 54 FR 40354, Sept. 29, 1989;
Section 25.965 Fuel tank tests.
(a) It must be shown by tests that the
(b) Each metallic tank with large unsupported or unstiffened...
(b)(4) of this section, the tank assembly
(i) If no frequency of vibration resulting from any r.p.m. w...
(b)(3)(i) of this section.
20 complete cycles per minute, through
(c) Except where satisfactory operating experience with a si...
12:50 Apr 30, 2019

Page 124 -   PAGE

Section 25.967
14 CFR Ch. I (1-1-19 Edition)
(d) For pressurized fuel tanks, it
1967; Amdt. 25-40, 42 FR 15043, Mar. 17, 1977]
(a) Each fuel tank must have a sump
(b) Each fuel tank must allow drainage of any hazardous quan...
(c) Each fuel tank sump must have
Section 25.967
(a) Each fuel tank must be supported
(i) Provisions are made for protection
(b) Spaces adjacent to tank surfaces
(c) The location of each tank must
(d) No engine nacelle skin immediately behind a major air ou...
(e) Each fuel tank must be isolated
Section 25.969
Section 25.971
Section 25.973
(a) [Reserved]
(b) Each recessed filler connection
(c) Each filler cap must provide a
(d) Each fuel filling point must have
...

Page 125 -   PAGE

Section 25.979
(i) Normal flight operation;
(i) Where the discharge of fuel from
(b) Carburetor vapor vents. Each carburetor with vapor elimi...
Section 25.977
(a) There must be a fuel strainer for
(b) [Reserved]
(c) The clear area of each fuel tank
(d) The diameter of each strainer
(e) Each finger strainer must be accessible for inspection a...
1974]
Section 25.979
(a) Each pressure fueling system fuel
(b) An automatic shutoff means must
(c) A means must be provided to prevent damage to the fuel s...
(d) The airplane pressure fueling system (not including fuel...
12:50 Apr 30, 2019

Page 126 -   PAGE

Section 25.981
14 CFR Ch. I (1-1-19 Edition)
(e) The airplane defueling system
1976; Amdt. 25-72, 55 FR 29785, July 20, 1990]
Section 25.981 Fuel tank explosion prevention.
(a) No ignition source may be present
(b) Except as provided in paragraphs
(b)(2) and (c) of this section, no fuel
(i) Equivalent Conventional Unheated
(c) Paragraph (b) of this section does
(d) To protect design features that
12:50 Apr 30, 2019

Page 127 -   PAGE

Section 25.997
1027, Amdt. No. 25-146, 83 FR 47556, Sept. 20,
2018]
Section 25.991
(a) Main pumps. Each fuel pump required for proper engine op...
(b) Emergency pumps. There must be
Section 25.993
(a) Each fuel line must be installed
(b) Each fuel line connected to components of the airplane b...
(c) Each flexible connection in fuel
(d) Flexible hose must be approved or
(e) No flexible hose that might be adversely affected by exp...
(f) Each fuel line within the fuselage
20, 1967]
Section 25.994 Fuel system components.
Section 25.721(b).
Section 25.995 Fuel valves.
Section 25.1189 for shutoff means, each fuel
(a) [Reserved]
(b) Be supported so that no loads resulting from their opera...
1977]
...

Page 128 -   PAGE

Section 25.999
14 CFR Ch. I (1-1-19 Edition)
(b) Have a sediment trap and drain
(c) Be mounted so that its weight is
(d) Have the capacity (with respect to
1984]
Section 25.999 Fuel system drains.
(a) Drainage of the fuel system must
(b) Each drain required by paragraph
(a) of this section must - 
(i) That is readily accessible and
1976]
Section 25.1001 Fuel jettisoning system.
(a) A fuel jettisoning system must be
25.121(d) at maximum takeoff weight,
(b) If a fuel jettisoning system is required it must be capa...
(c) Fuel jettisoning must be demonstrated beginning at maxim...
(d) During the flight tests prescribed
(e) For reciprocating engine powered
(f) For turbine engine powered airplanes, means must be prov...
10,000 feet and thereafter allowing 45
...

Page 129 -   PAGE

Section 25.1013
(g) The fuel jettisoning valve must be
(h) Unless it is shown that using any
(i) The fuel jettisoning system must
1968; Amdt. 25-57, 49 FR 6848, Feb. 23, 1984;
Section 25.1011 General.
(a) Each engine must have an independent oil system that can...
(b) The usable oil capacity may not
(c) Fuel/oil ratios higher than those
Section 25.1013 Oil tanks.
(a) Installation. Each oil tank installation must meet the r...
Section 25.967.
(b) Expansion space. Oil tank expansion space must be provid...
(c) Filler connection. Each recessed oil
(d) Vent. Oil tanks must be vented as
(e) Outlet. There must be means to
(f) Flexible oil tank liners. Each flexible oil tank liner m...
12:50 Apr 30, 2019

Page 130 -   PAGE

Section 25.1015
14 CFR Ch. I (1-1-19 Edition)
1968; Amdt. 25-23, 35 FR 5677, Apr. 8, 1970;
25-57, 49 FR 6848, Feb. 23, 1984; Amdt. 25-72, 55
Section 25.1015
(a) It can withstand, without failure,
(b) It meets the provisions of Section 25.965,
(i) For pressurized tanks used with a
p.s.i. plus the maximum operating
Section 25.965(c).
1974]
Section 25.1017
(a) Each oil line must meet the requirements of Section 25.9...
Section 25.1183.
(b) Breather lines must be arranged
Section 25.1019
(a) Each turbine engine installation
(b) Each oil strainer or filter in a
1984]
Section 25.1021
(a) Be accessible; and
...

Page 131 -   PAGE

Section 25.1023
Section 25.1043
(a) Each oil radiator must be able to
(b) Each oil radiator air duct must be
Section 25.1025
(a) Each oil shutoff must meet the requirements of Section 2...
(b) The closing of oil shutoff means
(c) Each oil valve must have positive
Section 25.1027
(a) If the propeller feathering system
(b) The amount of trapped oil must
(c) The ability of the system to accomplish feathering with ...
(d) Provision must be made to prevent sludge or other foreig...
1976]
Section 25.1041
Section 25.1043 Cooling tests.
(a) General. Compliance with Section 25.1041
(b) Maximum ambient atmospheric temperature. A maximum ambie...
(c) Correction factor (except cylinder
12:50 Apr 30, 2019
...

Page 132 -   PAGE

Section 25.1045
14 CFR Ch. I (1-1-19 Edition)
(d) Correction factor for cylinder barrel
1978]
Section 25.1045 Cooling test procedures.
(a) Compliance with Section 25.1041 must be
(b) Temperatures must be stabilized
(c) Cooling tests for each stage of
(d) For reciprocating engine powered
(e) For hull seaplanes and amphibians, cooling must be shown...
1984]
Section 25.1091
(a) The air induction system for each
(b) Each reciprocating engine must
(c) Air intakes may not open within
(d) For turbine engine powered airplanes and airplanes incor...
12:50 Apr 30, 2019

Page 133 -   PAGE

Section 25.1093
(e) If the engine induction system
33.78(a)(1) of this chapter without failure of parts or comp...
1976; Amdt. 25-40, 42 FR 15043, Mar. 17, 1977;
25-100, 65 FR 55854, Sept. 14, 2000]
Section 25.1093 Induction system icing protection.
(a) Reciprocating engines. Each reciprocating engine air ind...
100 SectionF. with the engine at 60 percent of
(b) Turbine engines. Except as provided in paragraph (b)(3) ...
(i) Adversely affect installed engine
12:50 Apr 30, 2019

Page 134 -   PAGE

Section 25.1101
14 CFR Ch. I (1-1-19 Edition)
1. Rime ice condition
0 to 15 SectionF (18 to Section9 SectionC)
15-25 microns ...........
2. Glaze ice condition
20 to 30 SectionF (Section7 to Section1
15 to 30 SectionF (Section9 to Section1
15-25 microns ...........
100 microns (minimum).
3. Large drop condition.
(c) Supercharged reciprocating engines.
1976; Amdt. 25-40, 42 FR 15043, Mar. 17, 1977;
25-72, 55 FR 29785, July 20, 1990; Amdt. 25-140,
79 FR 65526, Nov. 4, 2014]
Section 25.1101 Carburetor air preheater design.
(a) Ensure ventilation of the preheater when the engine is o...
(b) Allow inspection of the exhaust
(c) Allow inspection of critical parts
Section 25.1103 Induction system ducts and
(a) Each induction system duct upstream of the first stage o...
...

Page 135 -   PAGE

Section 25.1125
(b) No screen may be in any part of
(c) No screen may be deiced by alcohol alone; and
(d) It must be impossible for fuel to
Section 25.1107
Section 25.1121
(a) Each exhaust system must ensure
(b) Each exhaust system part with a
(c) Each component that hot exhaust
(d) No exhaust gases may discharge
(e) No exhaust gases may discharge
(f) Each exhaust system component
(g) Each exhaust shroud must be ventilated or insulated to a...
1977]
Section 25.1123
(a) Exhaust piping must be heat and
(b) Piping must be supported to withstand any vibration and ...
(c) Piping connected to components
1977]
Section 25.1125
(a) Each exhaust heat exchanger
...

Page 136 -   PAGE

Section 25.1127
14 CFR Ch. I (1-1-19 Edition)
1976]
Section 25.1127 Exhaust driven turbo-superchargers.
(a) Each exhaust driven turbo-supercharger must be approved ...
(b) There must be provisions for lubricating the turbine and...
(c) If the normal turbo-supercharger
Section 25.1141
(a) Each control must be located so
(b) Each flexible control must be approved or must be shown ...
(c) Each control must have sufficient
(d) Each control must be able to
(e) The portion of each powerplant
(f) For powerplant valve controls located in the flight deck...
(i) The selected position or function
1977; Amdt. 25-72, 55 FR 29785, July 20, 1990;
Section 25.1142 Auxiliary
Section 25.1143
(a) There must be a separate power or
(b) Power and thrust controls must
(c) Each power and thrust control
...

Page 137 -   PAGE

Section 25.1161
1976; Amdt. 25-57, 49 FR 6849, Feb. 23, 1984]
Section 25.1145
(a) Ignition switches must control
(b) There must be means to quickly
(c) Each group of ignition switches,
Section 25.1153
(a) There must be a separate propeller feathering control fo...
(b) If feathering is accomplished by
1967]
1977]
Section 25.1155 Reverse thrust and propeller
Section 25.1147
(a) If there are mixture controls,
(b) Each intermediate position of the
(c) The mixture controls must be accessible to both pilots. ...
Section 25.1149 Propeller
(d) The propeller speed and pitch controls must be to the ri...
(a) There must be a separate propeller speed and pitch contr...
(b) The controls must be grouped and
(c) The controls must allow synchronization of all propeller...
...

Page 138 -   PAGE

Section 25.1163
14 CFR Ch. I (1-1-19 Edition)
Section 25.1163 Powerplant accessories.
(a) Each engine mounted accessory
(b) Electrical equipment subject to
(c) If continued rotation of an enginedriven cabin superchar...
1984]
Section 25.1165 Engine ignition systems.
(a) Each battery ignition system
(b) The capacity of batteries and generators must be large e...
(c) The design of the engine ignition
(d) Magneto ground wiring (for separate ignition circuits) t...
(e) No ground wire for any engine
(f) Each ignition system must be
(g) There must be means to warn appropriate flight crewmembe...
(h) Each engine ignition system of a
1970; Amdt. 25-72, 55 FR 29785, July 20, 1990]
Section 25.1167 Accessory gearboxes.
(a) The engine with gearbox and connecting transmissions and...
(b) The accessory gearbox must meet
33.91 of this chapter, as applicable; and
...

Page 139 -   PAGE

Section 25.1187
(b) Each designated fire zone must
25.865, 25.867, 25.869, and 25.1185 through
25.1203.
1967; Amdt. 25-23, 35 FR 5677, Apr. 8, 1970;
25-115, 69 FR 40527, July 2, 2004]
Section 25.1182 Nacelle areas behind firewalls, and engine p...
(a) Each nacelle area immediately
25.1165 (d) and (e), 25.1183, 25.1185(c),
25.1187, 25.1189, and 25.1195 through
25.1203, including those concerning designated fire zones. H...
(b) For each area covered by paragraph (a) of this section t...
Section 25.1183 Flammable
(a) Except as provided in paragraph
(b) of this section, each line, fitting,
(b) Paragraph (a) of this section does
(c) All components, including ducts,
1967; Amdt. 25-36, 39 FR 35461, Oct. 1, 1974;
25-101, 65 FR 79710, Dec. 19, 2000]
Section 25.1185
(a) Except for the integral oil sumps
...

Page 140 -   PAGE

Section 25.1189
14 CFR Ch. I (1-1-19 Edition)
(b) Each designated fire zone must be
(c) No ventilation opening may be
(d) Each ventilation means must be
(e) Unless the extinguishing agent capacity and rate of disc...
Section 25.1189
(a) Each engine installation and each
(b) The closing of any fuel shutoff
(c) Operation of any shutoff may not
(d) Each flammable fluid shutoff
(e) No hazardous quantity of flammable fluid may drain into ...
(f) There must be means to guard
(g) Each tank-to-engine shutoff valve
(h) Each shutoff valve must have a
1970; Amdt. 25-57, 49 FR 6849, Feb. 23, 1984]
Section 25.1191
(a) Each engine, auxiliary power
(b) Each firewall and shroud must
Section 25.1192 Engine accessory section diaphragm.
Section 25.1193
...

Page 141 -   PAGE

Section 25.1199
(b) Cowling must meet the drainage
Section 25.1187.
(c) On airplanes with a diaphragm
(d) Each part of the cowling subject
(e) Each airplane must - 
Section 25.1195 Fire extinguishing systems.
(a) Except for combustor, turbine,
(b) The fire extinguishing system, the
(c) The fire extinguishing system for
1978]
Section 25.1197 Fire extinguishing agents.
(a) Fire extinguishing agents must - 
(b) If any toxic extinguishing agent is
1976; Amdt. 25-40, 42 FR 15044, Mar. 17, 1977]
Section 25.1199 Extinguishing
(a) Each extinguishing agent container must have a pressure ...
(b) The discharge end of each discharge line from a pressure...
12:50 Apr 30, 2019

Page 142 -   PAGE

Section 25.1201
14 CFR Ch. I (1-1-19 Edition)
(c) There must be a means for each
(d) The temperature of each container must be maintained, un...
(e) If a pyrotechnic capsule is used to
1970; Amdt. 25-40, 42 FR 15044, Mar. 17, 1977]
Section 25.1201 Fire extinguishing system
(a) No material in any fire extinguishing system may react c...
(b) Each system component in an engine compartment must be f...
Section 25.1203 Fire detector system.
(a) There must be approved, quick
(b) Each fire detector system must be
(c) No fire or overheat detector may
(d) There must be means to allow the
(e) Components of each fire or overheat detector system in a...
(f) No fire or overheat detector system component for any fi...
(g) Each fire detector system must be
(h) EWIS for each fire or overheat detector system in a fire...
1970; Amdt. 25-26, 36 FR 5493, Mar. 24, 1971;
Section 25.1207
(a) Tests of similar powerplant configurations;
...

Page 143 -   PAGE

Section 25.1303
Subpart F - Equipment
Section 25.1301 Function and installation.
(a) Each item of installed equipment
(b) EWIS must meet the requirements of subpart H of this par...
2007]
Section 25.1302 Installed systems and equipment for use by t...
(a) Flight deck controls must be installed to allow accompli...
(b) Flight deck controls and information intended for the fl...
(c) Operationally-relevant behavior
(d) To the extent practicable, installed equipment must inco...
2013]
Section 25.1303 Flight and navigation instruments.
(a) The following flight and navigation instruments must be ...
(b) The following flight and navigation instruments must be ...
12:50 Apr 30, 2019

Page 144 -   PAGE

Section 25.1305
14 CFR Ch. I (1-1-19 Edition)
360Section of pitch and roll and installed in
(c) The following flight and navigation instruments are requ...
1970; Amdt. 25-38, 41 FR 55467, Dec. 20, 1976;
Section 25.1305
(a) For all airplanes. (1) A fuel pressure warning means for...
(b) For reciprocating engine-powered
(i) An automatic propeller feathering
(c) For turbine engine-powered airplanes. In addition to the...
12:50 Apr 30, 2019

Page 145 -   PAGE

Section 25.1309
(d) For turbojet engine powered airplanes. In addition to th...
(i) Is not in the selected position, and
(e) For turbopropeller-powered airplanes. In addition to the...
(f) For airplanes equipped with fluid
1974; Amdt. 25-36, 39 FR 35461, Oct. 1, 1974;
25-54, 45 FR 60173, Sept. 11, 1980; Amdt. 25-72,
55 FR 29785, July 20, 1990; Amdt. 25-115, 69 FR
40527, July 2, 2004]
Section 25.1307 Miscellaneous equipment.
(a) [Reserved]
(b) Two or more independent sources
(c) Electrical protective devices, as
(d) Two systems for two-way radio
(e) Two systems for radio navigation,
1978; Amdt. 25-54, 45 FR 60173, Sept. 11, 1980;
Section 25.1309 Equipment, systems, and installations.
(a) The equipment, systems, and installations whose function...
(b) The airplane systems and associated components, consider...
12:50 Apr 30, 2019
...

Page 146 -   PAGE

Section 25.1310
14 CFR Ch. I (1-1-19 Edition)
(c) Warning information must be provided to alert the crew t...
(d) Compliance with the requirements of paragraph (b) of thi...
(e) In showing compliance with paragraphs (a) and (b) of thi...
(f) EWIS must be assessed in accordance with the requirement...
1976; Amdt. 25-41, 42 FR 36970, July 18, 1977;
Section 25.1310 Power source capacity and
(a) Each installation whose functioning is required for type...
(i) Any one engine on two-engine airplanes; and
(b) In determining compliance with
Section 25.1316 Electrical and electronic system lightning p...
(a) Each electrical and electronic
(b) Each electrical and electronic
12:50 Apr 30, 2019

Page 147 -   PAGE

Section 25.1321
33135, June 8, 2011]
Section 25.1317 High-intensity
(a) Except as provided in paragraph
(d) of this section, each electrical and
(b) Each electrical and electronic
(c) Each electrical and electronic system that performs a fu...
(d) Before December 1, 2012, an electrical or electronic sys...
2007]
Section 25.1321 Arrangement and visibility.
(a) Each flight, navigation, and powerplant instrument for u...
(b) The flight instruments required
(c) Required powerplant instruments
12:50 Apr 30, 2019

Page 148 -   PAGE

Section 25.1322
14 CFR Ch. I (1-1-19 Edition)
(d) Instrument panel vibration may
(e) If a visual indicator is provided to
1977]
Section 25.1322
(a) Flightcrew alerts must:
(i) Identify non-normal operation or
(b) Alerts must conform to the following prioritization hier...
(c) Warning and caution alerts must:
(d) The alert function must be designed to minimize the effe...
(e) Visual alert indications must:
(i) Red for warning alert indications.
(f) Use of the colors red, amber, and
Section 25.1323
(a) Each airspeed indicating instrument must be approved and...
(b) Each system must be calibrated
12:50 Apr 30, 2019

Page 149 -   PAGE

Section 25.1324
(c) The airspeed error of the installation, excluding the ai...
(d) From 1.23 VSR to the speed at
(e) From VMO to VMO + 2-3 (VDF Section
(f) There must be no indication of
(g) The effects of airspeed indicating
(h) Each system must be arranged, so
(i) Each system must have a heated
(m)
0 to 10 000 .........................
0 to 3000 ............................
(j) Where duplicate airspeed indicators are required, their ...
1984; Amdt. 25-108, 67 FR 70828, Nov. 26, 2002;
25-140, 79 FR 65526, Nov. 4, 2014]
Section 25.1324
0.5
...

Page 150 -   PAGE

Section 25.1325
14 CFR Ch. I (1-1-19 Edition)
(a) For airplanes certificated in accordance with Section 25...
(b) For airplanes certificated in accordance with Section 25...
(c) For airplanes certificated in accordance with Section 25...
Section 25.1325 Static pressure systems.
(a) Each instrument with static air
(b) Each static port must be designed
(i) For airplanes certificated in accordance with Section 25...
(c) The design and installation of the
(i) Unpressurized airplanes. Evacuate
1 minute, the loss of indicated altitude
(d) Each pressure altimeter must be
(e) Each system must be designed and
1.23 VSR0 with flaps extended and 1.7
(f) If an altimeter system is fitted
(g) Except as provided in paragraph
(h) of this section, if the static pressure
12:50 Apr 30, 2019

Page 151 -   PAGE

Section 25.1329
(h) For unpressurized airplanes, paragraph (g)(1) of this se...
1965; Amdt. 25-12, 32 FR 7587, May 24, 1967;
25-108, 67 FR 70828, Nov. 26, 2002; Amdt. 25-
140, 79 FR 65527, Nov. 4, 2014]
Section 25.1326 Pitot heat indication systems.
(a) The indication provided must incorporate an amber light ...
(b) The indication provided must be
Section 25.1327 Magnetic direction indicator.
(a) Each magnetic direction indicator
(b) The compensated installation
Section 25.1329 Flight guidance system.
(a) Quick disengagement controls for
(b) The effects of a failure of the system to disengage the ...
(c) Engagement or switching of the
(d) Under normal conditions, the disengagement of any automa...
(e) Under rare normal and non-normal conditions, disengageme...
(n)(2) of this section.
(f) The function and direction of motion of each command ref...
(g) Under any condition of flight appropriate to its use, th...
(h) When the flight guidance system
...

Page 152 -   PAGE

Section 25.1331
14 CFR Ch. I (1-1-19 Edition)
(i) The flight guidance system functions, controls, indicati...
(j) Following disengagement of the
(k) Following disengagement of the
(l) The autopilot may not create a
(m) During autothrust operation, it
(n) For purposes of this section, a
(i) Exceptional piloting skill, alertness, or strength.
Section 25.143(c).
11, 2006]
Section 25.1331 Instruments using a power
(a) For each instrument required by
Section 25.1303(b) that uses a power supply,
(b) As used in this section,  - instrument -  includes devic...
1977]
12:50 Apr 30, 2019

Page 153 -   PAGE

Section 25.1333
Section 25.1337
(a) Means must be provided to connect the required instrumen...
(b) The equipment, systems, and installations must be design...
(c) Additional instruments, systems,
1977]
Section 25.1337
(a) Instruments and instrument lines.
(i) Have restricting orifices or other
(b) Fuel quantity indicator. There
Section 25.959;
(c) Fuel flowmeter system. If a fuel
(d) Oil quantity indicator. There must
(e) Turbopropeller blade position indicator. Required turbop...
(f) Fuel pressure indicator. There must
1977]
12:50 Apr 30, 2019

Page 154 -   PAGE

Section 25.1351
14 CFR Ch. I (1-1-19 Edition)
Section 25.1351 General.
(a) Electrical system capacity. The required generating capa...
(b) Generating system. The generating
(c) External power. If provisions are
(d) Operation without normal electrical
1977; Amdt. 25-72, 55 FR 29785, July 20, 1990]
Section 25.1353 Electrical equipment and installations.
(a) Electrical equipment and controls
(b) Storage batteries must be designed and installed as foll...
(i) At maximum regulated voltage or
12:50 Apr 30, 2019

Page 155 -   PAGE

Section 25.1360
(i) A system to control the charging
(c) Electrical bonding must provide
Section 25.1355
(a) The distribution system includes
(b) [Reserved]
(c) If two independent sources of electrical power for parti...
1970; Amdt. 25-38, 41 FR 55468, Dec. 20, 1976]
Section 25.1357 Circuit protective devices.
(a) Automatic protective devices
(b) The protective and control devices in the generating sys...
(c) Each resettable circuit protective
(d) If the ability to reset a circuit
(e) Each circuit for essential loads
(f) For airplane systems for which
(g) Automatic reset circuit breakers
2007]
Section 25.1360
(a) Shock. The electrical system
12:50 Apr 30, 2019
...

Page 156 -   PAGE

Section 25.1362
14 CFR Ch. I (1-1-19 Edition)
(b) Burns. The temperature of any
Section 25.1362 Electrical supplies for emergency conditions...
Section 25.1363 Electrical system tests.
(a) When laboratory tests of the electrical system are condu...
(b) For each flight condition that
(c) Domestic appliances, particularly
(d) Unless compliance with Section 25.1309(b)
Section 25.1365 Electrical appliances, motors,
(a) Domestic appliances must be designed and installed so th...
(b) Galleys and cooking appliances
Section 25.1381
(a) The instrument lights must - 
(i) Their direct rays are shielded from
(b) Unless undimmed instrument
1990]
Section 25.1383
(a) Each landing light must be approved, and must be install...
(b) Except when one switch is used
12:50 Apr 30, 2019
...

Page 157 -   PAGE

Section 25.1389
(c) There must be a means to indicate
Section 25.1385 Position light system installation.
(a) General. Each part of each position light system must me...
25.1397.
(b) Forward position lights. Forward
(c) Rear position light. The rear position light must be a w...
(d) Light covers and color filters. Each
1976]
Section 25.1387 Position light system dihedral angles.
(a) Except as provided in paragraph
(e) of this section, each forward and
(b) Dihedral angle L (left) is formed
(c) Dihedral angle R (right) is formed
(d) Dihedral angle A (aft) is formed
(e) If the rear position light, when
1971]
Section 25.1389 Position light distribution
(a) General. The intensities prescribed
(b) Forward and rear position lights.
12:50 Apr 30, 2019
...

Page 158 -   PAGE

Section 25.1391
14 CFR Ch. I (1-1-19 Edition)
Section 25.1391 for the corresponding angles in
Section 25.1391 Minimum intensities in the
0Section to 10Section ..............
10Section to 20Section ............
20Section to 110Section ..........
110Section to 180Section ........
Section 25.1393 Minimum intensities in any
0Section ......................................................
0Section to 5Section ..........................................
5Section to 10Section .........................................
10Section to 15Section ........................................
15Section to 20Section ........................................
20Section to 30Section ........................................
30Section to 40Section ........................................
40Section to 90Section ........................................
...

Page 159 -   PAGE

Section 25.1399
Section 25.1403
(a) Each riding (anchor) light required for a seaplane or am...
(b) Externally hung lights may be
0.2 + (t 2  -  t 1 )
(a) General. The airplane must have
(b) Field of coverage. The system must
75 degrees above and 75 degrees below
(c) Flashing characteristics. The arrangement of the system,...
(d) Color. Each anticollision light
(f) Minimum effective intensities for
0Section to 5Section ..........................................
5Section to 10Section .........................................
10Section to 20Section ........................................
20Section to 30Section ........................................
30Section to 75Section ........................................
1971; Amdt. 25-41, 42 FR 36970, July 18, 1977]
...

Page 160 -   PAGE

Section 25.1411
14 CFR Ch. I (1-1-19 Edition)
Section 25.1411
(a) Accessibility. Required safety
(b) Stowage provisions. Stowage provisions for required emer...
(c) Emergency exit descent device. The
Section 25.810(a) must be at each exit for
(d) Liferafts. (1) The stowage provisions for the liferafts ...
Section 25.1415 must accommodate enough
(e) Long-range signaling device. The
(f) Life preserver stowage provisions.
(g) Life line stowage provisions. If certification for ditch...
1972; Amdt. 25-46, 43 FR 50598, Oct. 30, 1978;
25-70, 54 FR 43925, Oct. 27, 1989; Amdt. 25-79,
58 FR 45229, Aug. 26, 1993; Amdt. 25-116, 69 FR
62789, Oct. 27, 2004]
Section 25.1415 Ditching equipment.
(a) Ditching equipment used in airplanes to be certificated ...
(b) Each liferaft and each life preserver must be approved. ...
(c) Approved survival equipment
(d) There must be an approved survival type emergency locato...
...

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Section 25.1420
(b) To verify the ice protection analysis, to check for icin...
(c) Caution information, such as an
(d) For turbine engine powered airplanes, the ice protection...
(f) Unless the applicant shows that
(g) After the initial activation of the
(h) Procedures for operation of the
2007; Amdt. 25-129, 74 FR 38339, Aug. 3, 2009]
Section 25.1420 Supercooled large drop icing
(a) If certification for flight in icing
(a)(1), (2), or (3), of this section.
(i) The airplane must have a means
(i) The airplane must have a means
(b) To establish that the airplane can
(a) of this section, an applicant must
12:50 Apr 30, 2019

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Section 25.1421
14 CFR Ch. I (1-1-19 Edition)
(c) For an airplane certified in accordance with paragraph (...
Section 25.1419(e), (f), (g), and (h) must be met
(d) For the purposes of this section,
Section 25.1421 Megaphones.
Section 25.561(b)(3).
Section 25.1423
(a) Be powerable when the aircraft is
(b) Be capable of operation within 3
(c) Be intelligible at all passenger
(d) Be designed so that no unused,
(e) Be capable of functioning independently of any required ...
(f) Be accessible for immediate use
(g) For each required floor-level passenger emergency exit w...
2004]
12:50 Apr 30, 2019

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Section 25.1435
Section 25.1431 Electronic equipment.
(a) In showing compliance with
Section 25.1309 (a) and (b) with respect to
(b) Radio and electronic equipment
(c) Radio and electronic equipment,
(d) Electronic equipment must be designed and installed such...
16, 2004]
Section 25.1433 Vacuum systems.
1990]
Section 25.1435 Hydraulic systems.
(a) Element design. Each element of
1. Tubes and fittings. .........................
2. Pressure vessels containing gas:
3. Hoses ............................................
1.5
3.0
3.0
1.5
2.0
4.0
...

Page 164 -   PAGE

Section 25.1438
14 CFR Ch. I (1-1-19 Edition)
(c) Tests. Tests must be conducted on
Section 25.1438 Pressurization
(a) Pressurization system elements
(b) Pneumatic system elements must
(c) An analysis, or a combination of
Section 25.1439 Protective breathing equipment.
(a) Fixed (stationary, or built in) protective breathing equ...
(b) For protective breathing equipment required by paragraph...
(i) Masks covering the eyes, nose and
12:50 Apr 30, 2019

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Section 25.1443
760 mm. Hg. pressure is considered to
2004]
Section 25.1441 Oxygen equipment and supply.
(a) If certification with supplemental
25.1453.
(b) The oxygen system must be free
(c) There must be a means to allow
(d) The oxygen flow rate and the oxygen equipment for airpla...
Section 25.1443 Minimum mass flow of supplemental oxygen.
(a) If continuous flow equipment is
700 cc. with a constant time interval
(b) If demand equipment is installed
(c) For passengers and cabin attendants, the minimum mass fl...
10,000 feet up to and including 18,500
15 liters per minute, BTPS, and with a
18,500 feet up to and including 40,000
(d) If first-aid oxygen equipment is
(e) If portable oxygen equipment is
12:50 Apr 30, 2019
...

Page 166 -   PAGE

Section 25.1445
14 CFR Ch. I (1-1-19 Edition)
Section 25.1445 Equipment standards for the
(a) When oxygen is supplied to both
(b) Portable walk-around oxygen
Section 25.1447 Equipment standards for oxygen dispensing un...
(a) There must be an individual dispensing unit for each occ...
(b) If certification for operation up to
(c) If certification for operation
15,000 feet. The crew must be provided
(i) Can be placed on the face from its
(i) The diluter demand or pressure demand (pressure demand m...
12:50 Apr 30, 2019

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Section 25.1457
1977; Amdt. 25-87, 61 FR 28696, June 5, 1996;
Section 25.1449 Means for determining use of
Section 25.1450
(a) For the purpose of this section, a
(b) Each chemical oxygen generator
Section 25.795(d).
(c) In addition to meeting the requirements in paragraph (b)...
100 degrees F.
Section 25.1453 Protection of oxygen equipment from rupture.
(a) Protected from unsafe temperatures; and
(b) Located where the probability and
Section 25.1455 Draining of fluids subject to
Section 25.1457
(a) Each cockpit voice recorder required by the operating ru...
(b) The recording requirements of
12:50 Apr 30, 2019

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Section 25.1457
14 CFR Ch. I (1-1-19 Edition)
(c) Each cockpit voice recorder must
(i) Each boom, mask, or hand-held
(d) Each cockpit voice recorder must
(i) That provides 10 Section1 minutes of
(e) The recorder container must be
(e)(2) of this section, the recorder container must be locat...
12:50 Apr 30, 2019

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Section 25.1459
(f) If the cockpit voice recorder has a
(g) Each recorder container must - 
1965; Amdt. 25-16, 32 FR 13914, Oct. 6, 1967;
25-65, 53 FR 26143, July 11, 1988; Amdt. 25-124,
73 FR 12563, Mar. 7, 2008; 74 FR 32800, July 9,
2009]
Section 25.1459
(a) Each flight recorder required by
25.1327, as appropriate;
(b) Each nonejectable record container must be located and m...
(c) A correlation must be established
(d) Each recorder container must - 
12:50 Apr 30, 2019

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Section 25.1461
14 CFR Ch. I (1-1-19 Edition)
(e) Any novel or unique design or
25-41, 42 FR 36971, July 18, 1977; Amdt. 25-65,
53 FR 26144, July 11, 1988; Amdt. 25-124, 73 FR
12563, Mar. 7, 2008; 74 FR 32800, July 9, 2009]
Section 25.1461 Equipment containing high
(a) Equipment containing high energy rotors must meet paragr...
(c), or (d) of this section.
(b) High energy rotors contained in
(c) It must be shown by test that
(d) Equipment containing high energy rotors must be located ...
Subpart G - Operating Limitations
Section 25.1501
(a) Each operating limitation specified in SectionSection 25...
(b) The operating limitations and
Section 25.1503
Section 25.1505 Maximum
Section 25.253.
Section 25.1507
12:50 Apr 30, 2019
...

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Section 25.1521
Section 25.1511 Flap extended speed.
Section 25.1513 Minimum control speed.
Section 25.1515 Landing gear speeds.
(a) The established landing gear operating speed or speeds, ...
(b) The established landing gear extended speed VLE may not ...
1976]
Section 25.1516 Other speed limitations.
Section 25.1517 Rough air speed, VRA.
(a) A rough air speed, VRA, for use as
(b) At altitudes where VMO is not limited by Mach number, in...
(c) At altitudes where VMO is limited
Section 25.1519 Weight, center of gravity, and
25.27 must be established as operating
Section 25.1521 Powerplant limitations.
(a) General. The powerplant limitations prescribed in this s...
(b) Reciprocating engine installations.
(i) Maximum continuous power (relating to unsupercharged ope...
(c) Turbine engine installations. Operating limitations rela...
r.p.m., gas temperature, and time for - 
(i) Maximum continuous power or
...

Page 172 -   PAGE

Section 25.1522
14 CFR Ch. I (1-1-19 Edition)
(d) Ambient temperature. An ambient
2014]
Section 25.1522 Auxiliary power unit limitations.
Section 25.1523
1965]
Section 25.1527 Ambient air temperature and
Section 25.1529 Instructions
Section 25.1531
Section 25.1533 Additional operating limitations.
(a) The workload on individual crewmembers;
(b) The accessibility and ease of operation of necessary con...
(c) The kind of operation authorized
Section 25.1525
(a) Additional operating limitations
Section 25.121(a) through (c), for altitudes and
12:50 Apr 30, 2019

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Section 25.1549
25.113, for weights, altitudes, temperatures, wind component...
(b) The extremes for variable factors
(c) For airplanes certified in accordance with Section 25.14...
1976; Amdt. 25-72, 55 FR 29786, July 20, 1990;
25-140, 79 FR 65528, Nov. 4, 2014]
Section 25.1535
2007]
Section 25.1541
(a) The airplane must contain - 
(b) Each marking and placard
12:50 Apr 30, 2019
Section 25.1543 Instrument markings: general.
(a) When markings are on the cover
(b) Each instrument marking must
1990]
Section 25.1545 Airspeed limitation information.
Section 25.1583 (a) must be easily read and understood by th...
Section 25.1547 Magnetic direction indicator.
(a) A placard meeting the requirements of this section must ...
(b) The placard must show the calibration of the instrument ...
...

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Section 25.1551
14 CFR Ch. I (1-1-19 Edition)
(d) Each engine, auxiliary power
Section 25.1551
Section 25.1553
Section 25.1555
(a) Each cockpit control, other than
(b) Each aerodynamic control must
(c) For powerplant fuel controls - 
(d) For accessory, auxiliary, and
Section 25.729(e) must be marked so that the
Section 25.1557 Miscellaneous markings and
(a) Baggage and cargo compartments
(b) Powerplant fluid filler openings.
(i) The word  - fuel - ;
(c) Emergency exit placards. Each
(d) Doors. Each door that must be
1972; Amdt. 25-38, 41 FR 55468, Dec. 20, 1976;
Section 25.1561
(a) Each safety equipment control to
(b) Each location, such as a locker or
...

Page 175 -   PAGE

Section 25.1583
(c) Stowage provisions for required
(d) Each liferaft must have obviously
(e) Approved survival equipment
1978]
Section 25.1563
Section 25.1581
(a) Furnishing information. An Airplane Flight Manual must b...
(b) Approved information. Each part of
25.1587, that is appropriate to the airplane, must be furnis...
(c) [Reserved]
(d) Each Airplane Flight Manual
1990]
Section 25.1583
(a) Airspeed limitations. The following
(i) Full application of pitch, roll, or
(b) Powerplant limitations. The following information must b...
(c) Weight and loading distribution.
12:50 Apr 30, 2019

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Section 25.1585
14 CFR Ch. I (1-1-19 Edition)
(d) Flight crew. The number and functions of the minimum fli...
(e) Kinds of operation. The kinds of
(f) Ambient air temperatures and operating altitudes. The ex...
(g) [Reserved]
(h) Additional operating limitations.
(i) Maneuvering flight load factors. The
1976; Amdt. 25-42, 43 FR 2323, Jan. 16, 1978;
25-72, 55 FR 29787, July 20, 1990; Amdt. 25-105,
66 FR 34024, June 26, 2001; 75 FR 49818, Aug.
16, 2010]
Section 25.1585 Operating procedures.
(a) Operating procedures must be furnished for - 
(b) Information or procedures not directly related to airwor...
(c) Information identifying each operating condition in whic...
(d) The buffet onset envelopes, determined under Section 25....
(e) Information must be furnished
(f) Information on the total quantity
Section 25.1587 Performance information.
(a) Each Airplane Flight Manual
...

Page 177 -   PAGE

Section 25.1703
(i) Climb in the landing configuration.
Section 25.101(f) and (g) that are related to the
Subpart H - Electrical Wiring
63406, Nov. 8, 2007, unless otherwise noted.
Section 25.1701 Definition.
(a) As used in this chapter, electrical
(b) Except for the equipment indicated in paragraph (a)(14) ...
(i) Appropriate for the intended function and operating envi...
Section 25.1703 Function and installation:
(a) Each EWIS component installed
12:50 Apr 30, 2019

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Section 25.1705
14 CFR Ch. I (1-1-19 Edition)
(b) Selection of wires must take into
(c) The design and installation of the
(d) EWIS components located in
Section 25.1705
(a) EWIS associated with any system
(b) For systems to which the following rules apply, the comp...
Section 25.1707
(a) Each EWIS must be designed and
(b) Each EWIS must be designed and
(c) Wires and cables carrying heavy
(d) Each EWIS associated with independent airplane power sou...
(e) Except to the extent necessary to
(f) Except to the extent necessary to
12:50 Apr 30, 2019

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Section 25.1711
(g) Except to the extent necessary to
(h) Except to the extent necessary to
(i) EWIS must be designed and installed with adequate physic...
(j) EWIS must be designed and installed with adequate physic...
(k) For systems for which redundancy is required, by certifi...
(l) Each EWIS must be designed and
Section 25.1709
(a) Each catastrophic failure condition - 
(b) Each hazardous failure condition
Section 25.1711 Component
(a) EWIS components must be labeled
(b) For systems for which redundancy
(c) The identifying markings required by paragraphs (a) and ...
(d) The means used for identifying
12:50 Apr 30, 2019

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Section 25.1713
14 CFR Ch. I (1-1-19 Edition)
(e) Identification for EWIS modifications to the type design...
Section 25.1713 Fire protection: EWIS.
(a) All EWIS components must meet
(b) EWIS components that are located in designated fire zone...
(c) Insulation on electrical wire and
Section 25.1715 Electrical bonding and protection against st...
(a) EWIS components used for electrical bonding and protecti...
(b) On airplanes having grounded
Section 25.1717 Circuit protective devices:
Section 25.1719 Accessibility
Section 25.1721 Protection of EWIS.
(a) No cargo or baggage compartment
(b) EWIS must be designed and installed to minimize damage a...
(c) EWIS must be designed and installed to minimize damage a...
Section 25.1723 Flammable fluid fire protection: EWIS.
Section 25.1725 Powerplants: EWIS.
(a) EWIS associated with any powerplant must be designed and...
(b) Design precautions must be taken
Section 25.903(d)(1).
...

Page 181 -   PAGE

Section 25.1801
Section 25.1729 Instructions for Continued
Section 25.1731 Powerplant and APU fire detector system: EWI...
(a) EWIS that are part of each fire or
(b) No EWIS component of any fire or
(c) EWIS that are part of each fire or
Section 25.1203.
Section 25.1733 Fire detector systems, general: EWIS.
Subpart I - Special Federal
25-133, 76 FR 12555, Mar. 8, 2011, unless otherwise noted.
Section 25.1801 SFAR No. 111 - Lavatory Oxygen Systems.
12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

Page 189 -   PAGE

12:50 Apr 30, 2019
(a) Continuous maximum icing. The maximum continuous intensi...
(b) Intermittent maximum icing. The intermittent maximum int...

Page 190 -   PAGE

1!7.:
12:50 Apr 30, 2019
FIGURE 1
14 CFR Ch. I (1-1-19 Edition)

Page 191 -   PAGE

FIGURE 2
Section .,
12:50 Apr 30, 2019

Page 192 -   PAGE

1.4
1 .34 -I'..
1 .3
1 .2
1 0
1\..
30 40 50
14 CFR Ch. I (1-1-19 Edition)
1.1
12:50 Apr 30, 2019
FIGURE 3

Page 193 -   PAGE

1Section+3;.
2.0
1-
1Section
Section 1-~
2'
1 ~Section1
3'
3:8 i~O:
1-H, !-d+1-'-:Sectioni I~Section'
1 s:;:;fSectiont'
00: ~tg
22SectionFt':: 11.: fY
0.,
...

Page 194 -   PAGE

14 CFR Ch. I (1-1-19 Edition)
FIGURE 5
12:50 Apr 30, 2019

Page 195 -   PAGE

(c) Takeoff maximum icing. The maximum
4.0 5.0 6.0
2.0
1 .o
0.8
0.4 0.5!0.6
0.3
0.8
0.2
12:50 Apr 30, 2019
0"
0.9
1.0
1.5
u.
u.
...

Page 196 -   PAGE

14 CFR Ch. I (1-1-19 Edition)
(a) Ice accretions - General. The most critical ice accretio...
(b) In order to reduce the number of ice accretions to be co...
(c) The ice accretion that has the most adverse effect on ha...
(d) For both unprotected and protected
400 feet above the takeoff surface.
(e) The ice accretion before the ice protection system has b...
2007; 72 FR 50467, Aug. 31, 2007; Amdt. 25-129,
74 FR 38340, Aug. 3, 2009; Amdt. 25-140, 79 FR
65528, Nov. 4, 2014]
(a) Basic workload functions. The following
12:50 Apr 30, 2019

Page 197 -   PAGE

(b) Workload factors. The following workload factors are con...
(c) Kind of operation authorized. The determination of the k...
(a) Each applicant for an increase in the
(i) The installed standby power rocket engines have been sto...
(b) The currently approved maximum takeoff and landing weigh...
12:50 Apr 30, 2019

Page 198 -   PAGE

14 CFR Ch. I (1-1-19 Edition)
(a) The one-engine-inoperative takeoff
(b) The one-engine-inoperative takeoff
(c) The takeoff path with all engines operating, but without...
(d) For reciprocating-engine-powered airplanes, the takeoff ...
(a) The conditions of paragraphs (2)(b)
(b) Without the use of standby power, the
(a) The maximum certificated landing
(b) The flight path, with the engines operating at the power...
(i) The flight paths must be established
(a) The Administrator must find that the
(b) The procedure may not involve methods
12:50 Apr 30, 2019

Page 199 -   PAGE

(c) Allowances must be made for such time
(a) The standby power unit and its installation must not adv...
(b) The operation of the standby power
(a) Material test criteria - (1) Interior compartments occup...
(v) Except for small parts (such as knobs,
(a)(1)(i), (ii), (iii), or (iv) of part I of this appendix m...
(i) [Reserved]
(a)(1)(ii) of part I of this appendix and which
12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
(b) Test Procedures - (1) Conditioning. Specimens must be co...
50 percent Section5 percent relative humidity until
191 Model 5903 (revised Method 5902) for the
12:50 Apr 30, 2019

Page 201 -   PAGE

1550 SectionF. Suitable precautions must be taken
3-inch high flame with an inner cone approximately one-third...
(a) Criteria for Acceptance. Each seat cushion must meet the...
Section 25.853(c), does not exceed the corresponding
(b) Test Conditions. Vertical air velocity
12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
(c) Test Specimens. (1) For each test, one set
70 Section5 SectionF (21 Section2 SectionC) 55%Section10% re...
(d) Test Apparatus. The arrangement of the
5 and must include the components described
(i) Be a modified gun type;
3400. FAA published reports pertinent to this
(i) The calorimeter to be used in testing
4 Section1-8 inches (102 Section3 mm) from one side of the
(e) Preparation of Apparatus. Before calibration, all equipm...
(f) Calibration. To ensure the proper thermal output of the ...
2 minutes for warmup, and adjust the burner
10.5 Section0.5 BTU/ft2-sec. (11.9 Section0.6 w/cm2) on the
12:50 Apr 30, 2019

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(g) Test Procedure. The flammability of
(h) Test Report. With respect to all specimen sets tested fo...
12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
(a) Criteria for Acceptance. (1) At least three
12:50 Apr 30, 2019

Page 209 -   PAGE

(b) Summary of Method. This method provides a laboratory tes...
(c) Test Specimens. (1) The specimen to be
70 SectionF.Section5 SectionF. (21 SectionC. Section2 Sectio...
(d) Test Apparatus. The arrangement of the
(i) Be a modified gun type.
11 inches (280 mm) wide as shown in Figure
3 of Part II of this appendix.
2 of this part of this appendix.
8 inches from the ceiling liner panel and 2
(e) Preparation of Apparatus. Before calibration, all equipm...
(d)(2).
(f) Calibration. To ensure the proper thermal output of the ...
2 minutes for warm-up, and adjust the damper to produce a ca...
2 through 5 until proper readings are obtained.
12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
(g) Test Procedure. (1) Mount a thermocouple of the same typ...
(h) Test Report. The test report must include the following:
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

Page 213 -   PAGE

12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
(a) Summary of Method. Three or more
(b) Apparatus. The Ohio State University
1.18 inch (30 mm) from the center along the
5 of this part IV). The cold junctions must be
28 drill holes must be mounted 6 inches (152
2.75 inches (133  70 mm) in cross section, and
10 inches (254 mm) long, fabricated from 28
3.0 inch (25  76 mm) baffle plate of .018 Section.002
12:50 Apr 30, 2019

Page 215 -   PAGE

1-2-inch Kaowool  - M -  board inserted in the
180 degrees and be calibrated for incident
(b)(8)(ii) or (b)(8)(iii) of this part IV, respectively. Sin...
(i) Lower Pilot Burner. The pilot-flame tubing must be .25 i...
(c) Calibration of Equipment - (1) Heat Release Rate. A cali...
(d) Preparation of Test Specimens. (1) The
12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
(e) Procedure. (1) The power supply to the
22.41
(g) Criteria. The total positive heat release
12:50 Apr 30, 2019
(f) Calculations. (1) The calibration factor is

Page 217 -   PAGE

(h) Report. The test report must include
12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019
FIGURES TO PART IV OF APPENDIX F

Page 219 -   PAGE

12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
(a) Definitions.
12:50 Apr 30, 2019
(a) Summary of Method. The specimens
83.
(b) Acceptance Criteria. The specific optical

Page 225 -   PAGE

(b) Test apparatus.
55 inches (1397 mm) long by 19.5 (495 mm)
12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019
3-inch wide emitter strips. The emitter strips

Page 227 -   PAGE

12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
(i) Electric radiant panel. The radiant panel
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

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14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

Page 231 -   PAGE

(i) Calorimeter specification.
12:50 Apr 30, 2019

Page 232 -   PAGE

14 CFR Ch. I (1-1-19 Edition)
(c) Test specimens. (1) Specimen preparation.
(d) Specimen conditioning. Condition the
(e) Apparatus Calibration. (1) With the sliding platform out...
12:50 Apr 30, 2019

Page 233 -   PAGE

(f) Test Procedure. (1) Ignite the pilot burner. Ensure that...
1.5
1.51-1.50-1.49
1.43-1.44
1.7
1.71-1.70-1.69
1.62-1.63
1-2 inch (12 mm) above the sample. See figure
7. A stop, as shown in figure 8, allows the operator to posi...
12:50 Apr 30, 2019

Page 234 -   PAGE

14 CFR Ch. I (1-1-19 Edition)
2 inches (51 mm) above the specimen.
(g) Report. (1) Identify and describe the
(h) Requirements. (1) There must be no
12:50 Apr 30, 2019

Page 235 -   PAGE

(a) Definitions.
(b) Apparatus. (1) The arrangement of the
12:50 Apr 30, 2019

Page 236 -   PAGE

14 CFR Ch. I (1-1-19 Edition)
12:50 Apr 30, 2019

Page 237 -   PAGE

(i) Nozzle. A nozzle must maintain the fuel
6.0 gal/hr at 100 lb/in2 (0.71 MPa) delivers a
12:50 Apr 30, 2019

Page 238 -   PAGE

14 CFR Ch. I (1-1-19 Edition)
3.5 inches (89 mm) in width.
(v) Burner cone. Install a 12 + 0.125-inch (305
12:50 Apr 30, 2019

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12:50 Apr 30, 2019

Page 240 -   PAGE

14 CFR Ch. I (1-1-19 Edition)
22.7 W/cm 2), accurate to Section3% of the indicated
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14 CFR Ch. I (1-1-19 Edition)
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(v) Air velocity meter. Use a vane-type air
1, except for the center vertical former,
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14 CFR Ch. I (1-1-19 Edition)
(i) The calorimeters must be a total heat
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(i) Ventilation hood. Provide the test chamber with an exhau...
(c) Test Specimens. (1) Specimen preparation.
(i) For batt-type materials such as fiberglass, the construc...
(i) Fire barrier material. If the insulation
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14 CFR Ch. I (1-1-19 Edition)
(v) Conditioning. Condition the specimens
(d) Preparation of apparatus. (1) Level and
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(e) Calibration. (1) Position the burner in

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14 CFR Ch. I (1-1-19 Edition)
80.80 ft3/min (2.29 m3/min) is equivalent.)
(f) Test procedure. (1) Secure the two insulation blanket te...
(g) Report. (1) Identify and describe the
(h) Requirements. (1) Each of the two insulation blanket tes...
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(a) This appendix specifies requirements
25.1729, and applicable provisions of parts 21
(b) The Instructions for Continued Airworthiness for each ai...
(c) The applicant must submit to the FAA
(a) The Instructions for Continued Airworthiness must be in ...
(b) The format of the manual or manuals
(a) Airplane maintenance manual or section.
(b) Maintenance instructions. (1) Scheduling
(c) Diagrams of structural access plates
(d) Details for the application of special inspection techni...
(e) Information needed to apply protective
(f) All data relative to structural fasteners
(g) A list of special tools needed.
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14 CFR Ch. I (1-1-19 Edition)
(a) The Instructions for Continued Airworthiness must contai...
25.1701.
Section 25.954.
(b) If the Instructions for Continued Airworthiness consist ...
(a) The applicant must prepare Instructions for Continued Ai...
(i) Identification of each zone of the airplane.
(v) Identification of - 
(b) The EWIS ICA developed in accordance
1989; Amdt. 25-102, 66 FR 23130, May 7, 2001;
25-132, 75 FR 69782, Nov. 15, 2010; Doc. No.
(a) This appendix specifies additional requirements for inst...
(b) With the ATTCS and associated systems functioning normal...
(a) Automatic Takeoff Thrust Control System
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(b) Critical Time Interval. When conducting
(a) An ATTCS failure or a combination of
(b) The concurrent existence of an ATTCS
(c) All applicable performance requirements of Part 25 must ...
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14 CFR Ch. I (1-1-19 Edition)
(a) Ninety (90) percent of the thrust or
(b) That required to permit normal operation of all safety-r...
(c) That shown to be free of hazardous engine response chara...
(a) In addition to the requirements of
Section 25.1141, no single failure or malfunction, or
(b) The ATTCS must be designed to:
(b), and (c);
(a) A means must be provided to indicate
(b) If the inherent flight characteristics of
Section 25.803:
(a) The emergency evacuation must be conducted with exterior...
(b) The airplane must be in a normal attitude with landing g...
(c) Unless the airplane is equipped with an
(d) Except as provided in paragraph (a) of
(e) All emergency equipment required for
(f) Each internal door or curtain must be
(g) Each crewmember must be seated in
(h) A representative passenger load of persons in normal hea...
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...

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(i) No passenger may be assigned a specific
(g) of this paragraph, no employee of the applicant may be s...
(j) Seat belts and shoulder harnesses (as required) must be ...
(k) Before the start of the demonstration,
(l) No prior indication may be given to any
(m) The applicant may not practice, rehearse, or describe th...
(n) Prior to entering the demonstration
(o) The airplane must be configured to prevent disclosure of...
(p) Exits used in the demonstration must
(q) Except as provided in paragraph (c) of
(r) The applicant-s approved procedures
(s) The evacuation time period is completed when the last oc...
25-117, 69 FR 67499, Nov. 17, 2004]
(a) Operation in icing conditions.
(i) Icing conditions encountered at an altitude that the air...
(b) Electrical power supply. The airplane
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14 CFR Ch. I (1-1-19 Edition)
(c) Time limited systems. The applicant must
(a) Fuel system design. Fuel necessary to
(i) Airplane demonstration-testing must
(b) APU design. If an APU is needed to comply with this appe...
(c) Engine oil tank design. The engine oil
(a) Special limitations, including any limitation associated...
(b) Required markings or placards.
(c) The airborne equipment required for extended operations ...
(d) The system time capability for the following:
(e) This statement:  - The type-design reliability and perfo...
14 CFR 25.1535 and found suitable for (identify maximum appr...
(a) Service experience. The world fleet for
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(b) In-flight shutdown (IFSD) rates. The
(c) Propulsion system assessment. (1) The applicant must con...
(i) A list of all IFSD-s, unplanned ground
(v) The mean time between failures
(i) For an item where the manufacturer is
(d) Airplane systems assessment. The applicant must conduct ...
1 significant system that has or could result
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14 CFR Ch. I (1-1-19 Edition)
(e) Airplane flight test. The applicant must
(a) Assessment of relevant experience with airplanes previou...
(b) Propulsion system design. (1) The engine
(i) An IFSD rate of 0.02 or less per 1,000
(c) Maintenance and operational procedures.
(d) Propulsion system validation test. (1) The
Section 33.201(c) of this chapter. The test engine
(i) Visually inspected according to the applicant-s on-wing ...
Section 25.1529.
(h) of this appendix.
(e) New technology testing. Technology new
(f) APU validation test. If an APU is needed
(g) Airplane demonstration. For each airplane-engine combina...
(i) Flights simulating actual ETOPS, including flight at nor...
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(v) Diversions to airports that represent
(h) Problem tracking and resolution system.
(i) Contain a process for prompt reporting
Section 21.4(a)(6) encountered during the phases of
(i) Requires a new engine type certificate ....................
(i) Acceptance criteria. The type and frequency of failures ...
(a) A service experience requirement of not
(b) The Early ETOPS requirements of
(c) The flight test requirement of section
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14 CFR Ch. I (1-1-19 Edition)
(a) Service experience. The world fleet for
(b) Airplane systems assessment. The applicant must conduct ...
1 significant system that has or could result
(c) Airplane flight test. The applicant must
(a) Maintenance and operational procedures.
(b) New technology testing. Technology new
(c) APU validation test. If an APU is needed
(d) Airplane demonstration. For each airplane-engine combina...
(i) Flights simulating actual ETOPS including flight at norm...
(v) Diversions to airports that represent
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(e) Problem tracking and resolution system.
(i) Contain a process for prompt reporting
Section 21.4(a)(6) encountered during the phases of
(i) Requires a new engine type certificate ....................
(f) Acceptance criteria. The type and frequency of failures ...
(a) A service experience requirement of
(b) The Early ETOPS requirements of section K25.3.2 of this ...
(c) The flight test requirement of section
2007, as amended by Doc. No. FAA-2018-0119,
(a) HIRF environment I is specified in the
10 kHz-2 MHz ...................................
2 MHz-30 MHz .................................
30 MHz-100 MHz .............................
100 MHz-400 MHz ...........................
400 MHz-700 MHz ...........................
700 MHz-1 GHz ................................
1 GHz-2 GHz ....................................
2 GHz-6 GHz ....................................
6 GHz-8 GHz ....................................
8 GHz-12 GHz ..................................
12 GHz-18 GHz ................................
...

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14 CFR Ch. I (1-1-19 Edition)
30 MHz-100 MHz .............................
100 MHz-200 MHz ...........................
200 MHz-400 MHz ...........................
400 MHz-1 GHz ................................
1 GHz-2 GHz ....................................
2 GHz-4 GHz ....................................
4 GHz-6 GHz ....................................
6 GHz-8 GHz ....................................
8 GHz-12 GHz ..................................
12 GHz-18 GHz ................................
18 GHz-40 GHz ................................
1,300
3,000
3,000
1,230
...

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(a) Reliability indications must be provided to identify fai...
(b) Sufficient accessibility to FRM reliability indications ...
(c) The access doors and panels to the fuel
(a) If FRM is used to comply with paragraph M25.1 of this ap...
(b) Maintenance procedures must be developed to identify any...
(a) Demonstrate effective means to ensure
(b) Unless alternative reporting procedures
(c) Develop service instructions or revise
21, 2008, as amended by Doc. No. FAA-2018-
0119, Amdt. 25-145, 83 FR 9169, Mar. 5, 2018]
(a) This appendix specifies the requirements for conducting ...
(b) This appendix defines parameters affecting fuel tank fla...
(c) The following definitions, input variables, and data tab...
(a) Bulk Average Fuel Temperature means
(b) Flammability Exposure Evaluation Time
(c) Flammable. With respect to a fluid or
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14 CFR Ch. I (1-1-19 Edition)
(d) Flash Point. The flash point of a flammable fluid means ...
(e) Fleet average flammability exposure is the
(f) Gaussian Distribution is another name
(g) Hazardous atmosphere. An atmosphere
(h) Inert. For the purpose of this appendix,
(i) Inerting. A process where a noncombustible gas is introd...
(j) Monte Carlo Analysis. The analytical
(k) Oxygen evolution occurs when oxygen
(l) Standard deviation is a statistical measure of the dispe...
(m) Transport Effects. For purposes of this
(n) Ullage. The volume within the fuel tank
(a) A flammability exposure analysis must
(b) The following parameters are defined in
2008, document number DOT/FAA/AR-05/8
(c) Parameters that are specific to the particular airplane ...
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(d) Fuel Tank FRM Model. If FRM is used,
(e) The applicant must submit to the responsible Aircraft Ce...
(a) Atmospheric Ambient Temperatures
(i) For Jet A fuel, the variation of flash
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14 CFR Ch. I (1-1-19 Edition)
59.95
20.14
17.28
(b) The Flight Length Distribution defined
11.7
...

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0.0
...

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14 CFR Ch. I (1-1-19 Edition)
PART I - METEOROLOGY
(a) Freezing Drizzle (Conditions with spectra maximum drop d...
500 Sectionm):
17.4 nautical miles.
(b) Freezing Rain (Conditions with spectra
17.4 nautical miles.
(c) Horizontal extent.
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14 CFR Ch. I (1-1-19 Edition)
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14 CFR Ch. I (1-1-19 Edition)
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14 CFR Ch. I (1-1-19 Edition)
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(a) General. The most critical ice accretion
(b) of this Appendix.
(c) of this Appendix.
(b) Ice accretions for airplanes certified in
Section 25.1420(a)(1), plus:
(i) Pre-detection ice as defined by part II,
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PART II - AIRFRAME ICE ACCRETIONS

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14 CFR Ch. I (1-1-19 Edition)
Section 25.1420(a)(2), or defined by part II, paragraph
(a)(4), of Appendix C of this part, for an airplane
Section 25.1420(a)(1), plus:
(i) Pre-detection ice as defined by part II,
(b)(2), of this Appendix, or the ice calculated
(i) For an airplane certified in accordance
(b)(2), of this Appendix, or the ice calculated
(i) For an airplane certified in accordance
200 feet above the landing surface with a
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(i) For an airplane certified in accordance
(c) Ice accretions for airplanes certified in accordance wit...
Section 25.1420(a)(2), only the portion of the icing
400 feet above the takeoff surface, assuming
(i) Ice accumulated in the icing conditions
(i) Ice accretion defined by part II, paragraph (c)(5)(i), o...
2,000 feet above the landing surface to a
(i) The airfoils, control surfaces, and, if applicable, prop...
(v) Crew activation of the ice protection
400 feet above the takeoff surface.
(d) The ice accretion before the ice protection system has b...
(e) In order to reduce the number of ice accretions to be co...
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14 CFR Ch. I (1-1-19 Edition)
(f) The ice accretion that has the most adverse effect on ha...
PART 26 - CONTINUED AIRWORTHINESS AND SAFETY IMPROVEMENTS FO...
Subpart A - General
26.1 Purpose and scope.
26.3 [Reserved]
26.5 Applicability table.
Subpart B - Enhanced Airworthiness
26.11 Electrical wiring interconnection systems (EWIS) maint...
Subpart C - Aging Airplane Safety - 
26.21
26.23
Subpart D - Fuel Tank Flammability
26.31 Definitions.
26.33 Holders of type certificates: Fuel tank
26.35 Changes to type certificates affecting
26.37 Pending type certification projects:
26.39 Newly produced airplanes: Fuel tank
Subpart E - Aging Airplane Safety - Damage Tolerance Data fo...
26.41 Definitions.
26.43 Holders of and applicants for type certificates - Repa...
...