Code of Federal Regulations - Title 14

950

14 CFR Ch. I (1–1–14 Edition)

Pt. 36, App. B

(A): For airplanes with more than three jet

engines—700 feet (214 meters).

(B): For all other airplanes—1,000 feet (305

meters).

(ii) For Stage 2 airplanes that have jet en-

gines with a bypass ratio of 2 or more and for
Stage 3 airplanes, the following apply:

(A): For airplanes with more than three en-

gines—689 feet (210 meters).

(B): For airplanes with three engines—853

feet (260 meters).

(C): For airplanes with fewer than three

engines—984 feet (300 meters).

(2) Upon reaching the height specified in

paragraph (b)(1) of this section, airplane
thrust or power must not be reduced below
that required to maintain either of the fol-
lowing, whichever is greater:

(i) A climb gradient of 4 per cent; or
(ii) In the case of multi-engine airplanes,

level flight with one engine inoperative.

(3) For the purpose of determining the lat-

eral noise level, the reference flight path
must be calculated using full takeoff power
throughout the test run without a reduction
in thrust or power. For tests conducted be-
fore August 7, 2002, a single reference flight
path that includes thrust cutback in accord-
ance with paragraph (b)(2) of this section, is
an acceptable alternative in determining the
lateral noise level.

(4) The takeoff reference speed is the all-

engine operating takeoff climb speed se-
lected by the applicant for use in normal op-
eration; this speed must be at least V2+10kt
(V2+19km/h) but may not be greater than
V2+20kt (V2+37km/h). This speed must be at-
tained as soon as practicable after lift-off
and be maintained throughout the takeoff
noise certification test. For Concorde air-
planes, the test day speeds and the acoustic
day reference speed are the minimum ap-
proved value of V2+35 knots, or the all-en-
gines-operating speed at 35 feet, whichever
speed is greater as determined under the reg-
ulations constituting the type certification
basis of the airplane; this reference speed
may not exceed 250 knots. For all airplanes,
noise values measured at the test day speeds
must be corrected to the acoustic day ref-
erence speed.

(5) The takeoff configuration selected by

the applicant must be maintained constantly
throughout the takeoff reference procedure,
except that the landing gear may be re-
tracted. Configuration means the center of
gravity position, and the status of the air-
plane systems that can affect airplane per-
formance or noise. Examples include, the po-
sition of lift augmentation devices, whether
the APU is operating, and whether air bleeds
and engine power take-offs are operating;

(6) The weight of the airplane at the brake

release must be the maximum takeoff weight
at which the noise certification is requested,
which may result in an operating limitation
as specified in § 36.1581(d); and

(7) The average engine is defined as the av-

erage of all the certification compliant en-
gines used during the airplane flight tests,
up to and during certification, when oper-
ating within the limitations and according
to the procedures given in the Flight Man-
ual. This will determine the relationship of
thrust/power to control parameters (e.g., N

or EPR). Noise measurements made during
certification tests must be corrected using
this relationship.

calculated using the following:

(1) The airplane is stabilized and following

a 3

glide path;

(2) For subsonic airplanes, a steady ap-

proach speed of V

ref

+ 10 kts (V

ref

+ 19 km/h)

with thrust and power stabilized must be es-
tablished and maintained over the approach
measuring point. V

ref

is the reference landing

speed, which is defined as the speed of the
airplane, in a specified landing configura-
tion, at the point where it descends through
the landing screen height in the determina-
tion of the landing distance for manual land-
ings. For Concorde airplanes, a steady ap-
proach speed that is either the landing ref-
erence speed + 10 knots or the speed used in
establishing the approved landing distance
under the airworthiness regulations consti-
tuting the type certification basis of the air-
plane, whichever speed is greater. This speed
must be established and maintained over the
approach measuring point.

(3) The constant approach configuration

used in the airworthiness certification tests,
but with the landing gear down, must be
maintained throughout the approach ref-
erence procedure;

(4) The weight of the airplane at touch-

down must be the maximum landing weight
permitted in the approach configuration de-
fined in paragraph (c)(3) of this section at
which noise certification is requested, except
as provided in § 36.1581(d) of this part; and

(5) The most critical configuration must be

used; this configuration is defined as that
which produces the highest noise level with
normal deployment of aerodynamic control
surfaces including lift and drag producing
devices, at the weight at which certification
is requested. This configuration includes all
those items listed in section A36.5.2.5 of ap-
pendix A of this part that contribute to the
noisiest continuous state at the maximum
landing weight in normal operation.

Section B36.8 Noise Certification Test

Procedures

(a) All test procedures must be approved by

the FAA.

(b) The test procedures and noise measure-

ments must be conducted and processed in
an approved manner to yield the noise eval-
uation metric EPNL, in units of EPNdB, as
described in appendix A of this part.

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