808 

14 CFR Ch. I (1–1–19 Edition) 

Pt. 36, App. B 

point where at least the following height 
above runway level is reached. The takeoff 
thrust/power used must be the maximum 
available for normal operations given in the 
performance section of the airplane flight 
manual under the reference atmospheric 
conditions given in section B36.7(a)(5). 

(i) For Stage 1 airplanes and for Stage 2 

airplanes that do not have jet engines with a 
bypass ratio of 2 or more, the following 
apply: 

(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 
attained 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

1

 

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

(c) Approach reference procedure: 
The approach reference flight path must be 

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 

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