Code of Federal Regulations - Title 14

373

Federal Aviation Administration, DOT

§ 25.101

loading and flight requirement is
shown, except that for airplanes
equipped with standby power rocket
engines the maximum weight must not
be more than the highest weight estab-
lished in accordance with appendix E of
this part; or

(3) The highest weight at which com-

pliance is shown with the certification
requirements of Part 36 of this chapter.

(b)

Minimum weight. The minimum

weight (the lowest weight at which
compliance with each applicable re-
quirement of this part is shown) must
be established so that it is not less
than—

(1) The lowest weight selected by the

applicant;

(2) The design minimum weight (the

lowest weight at which compliance
with each structural loading condition
of this part is shown); or

(3) The lowest weight at which com-

pliance with each applicable flight re-
quirement is shown.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–23, 35 FR 5671, Apr. 8,
1970; Amdt. 25–63, 53 FR 16365, May 6, 1988]

§ 25.27

Center of gravity limits.

The extreme forward and the extreme

aft center of gravity limitations must
be established for each practicably sep-
arable operating condition. No such
limit may lie beyond—

(a) The extremes selected by the ap-

plicant;

(b) The extremes within which the

structure is proven; or

pliance with each applicable flight re-
quirement is shown.

§ 25.29

Empty weight and cor-

responding center of gravity.

(a) The empty weight and cor-

responding center of gravity must be
determined by weighing the airplane
with—

(1) Fixed ballast;
(2) Unusable fuel determined under

§ 25.959; and

(3) Full operating fluids, including—
(i) Oil;
(ii) Hydraulic fluid; and
(iii) Other fluids required for normal

operation of airplane systems, except
potable water, lavatory precharge

water, and fluids intended for injection
in the engine.

(b) The condition of the airplane at

the time of determining empty weight
must be one that is well defined and
can be easily repeated.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–42, 43 FR 2320, Jan. 16,
1978; Amdt. 25–72, 55 FR 29774, July 20, 1990]

§ 25.31

Removable ballast.

Removable ballast may be used on

showing compliance with the flight re-
quirements of this subpart.

§ 25.33

Propeller speed and pitch lim-

its.

(a) The propeller speed and pitch

must be limited to values that will en-
sure—

(1) Safe operation under normal oper-

ating conditions; and

(2) Compliance with the performance

requirements of §§ 25.101 through 25.125.

(b) There must be a propeller speed

limiting means at the governor. It
must limit the maximum possible gov-
erned engine speed to a value not ex-
ceeding the maximum allowable r.p.m.

pitch position of the propeller blades
must be set so that the engine does not
exceed 103 percent of the maximum al-
lowable engine rpm or 99 percent of an
approved maximum overspeed, which-
ever is greater, with—

(1) The propeller blades at the low

pitch limit and governor inoperative;

(2) The airplane stationary under

standard atmospheric conditions with
no wind; and

(3) The engines operating at the take-

off manifold pressure limit for recipro-
cating engine powered airplanes or the
maximum takeoff torque limit for tur-
bopropeller engine-powered airplanes.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–57, 49 FR 6848, Feb. 23,
1984; Amdt. 25–72, 55 FR 29774, July 20, 1990]

ERFORMANCE

§ 25.101

General.

(a) Unless otherwise prescribed, air-

planes must meet the applicable per-
formance requirements of this subpart
for ambient atmospheric conditions
and still air.

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