973 

Federal Aviation Administration, DOT 

Pt. 36, App. J 

may be exceeded by one or two of the take-
off, flyover, or approach calculated noise lev-
els determined under section H36.203 of this 
appendix if 

(1) The sum of the exceedances is not 

greater than 4 EPNdB; 

(2) No exceedance is greater than 3 EPNdB; 

and 

(3) The exceedances are completely offset 

by reduction in the other required calculated 
noise levels. 

[Amdt. 36–14, 53 FR 3541, Feb. 5, 1988; 53 FR 
4099, Feb. 11, 1988; 53 FR 7728, Mar. 10, 1988, as 
amended by Amdt. 36–54, 67 FR 45237, July 8, 
2002; Amdt. 36–25, 69 FR 31234, June 2, 2004; 
Amdt. 36–25, 69 FR 41573, July 9, 2004] 

A

PPENDIX

I 

TO

P

ART

36 [R

ESERVED

] 

A

PPENDIX

J 

TO

P

ART

36—A

LTERNATIVE

 

N

OISE

C

ERTIFICATION

P

ROCEDURE

 

FOR

H

ELICOPTERS

U

NDER

S

UBPART

H 

H

AVING

A

M

AXIMUM

C

ERTIFICATED

 

T

AKEOFF

W

EIGHT

OF

N

OT

M

ORE

 

T

HAN

7,000 P

OUNDS

 

PART A

—

REFERENCE CONDITIONS

 

Sec. 

J36.1 

General. 

J36.3 

Reference Test Conditions. 

J36.5 [Reserved] 

PART B

—

NOISE MEASUREMENT PROCEDURE

 

UNDER

§ 36.801 

J36.101 

Noise certification test and measurement 

conditions. 

J36.103 [Reserved] 
J36.105 

Flyover test conditions. 

J36.107 [Reserved] 
J36.109 

Measurement of helicopter noise received 

on the ground. 

J36.111 

Reporting requirements. 

J36.113 [Reserved] 

PART C

—

NOISE EVALUATION AND CALCULATION

 

UNDER

§ 36.803 

J36.201 

Noise evaluation in SEL. 

J36.203 

Calculation of noise levels. 

J36.205 

Detailed data correction procedures. 

PART D

—

NOISE LIMITS PROCEDURE UNDER

 

§ 36.805 

J36.301 

Noise measurement, evaluation, and cal-

culation. 

J36.303 [Reserved] 
J36.305 

Noise limits. 

PART A

—

REFERENCE CONDITIONS

 

Section J36.1 General. 

This appendix prescribes the alternative 

noise certification requirements identified 
under § 36.1 of this part and subpart H of this 
part for helicopters in the primary, normal, 

transport, and restricted categories having 
maximum certificated takeoff weight of not 
more than 7,000 pounds including: 

(a) The conditions under which an alter-

native noise certification test under subpart 
H of this part must be conducted and the al-
ternative measurement procedure that must 
be used under § 36.801 of this part to measure 
the helicopter noise during the test; 

(b) The alternative procedures which must 

be used under § 36.803 of this part to correct 
the measured data to the reference condi-
tions and to calculate the noise evaluation 
quantity designated as Sound Exposure 
Level (SEL); and 

(c) The noise limits for which compliance 

must be shown under § 36.805 of this part. 

Section J36.3 Reference Test Conditions. 

(a) 

Meteorological conditions. The following 

are the noise certification reference atmos-
pheric conditions which shall be assumed to 
exist from the surface to the helicopter alti-
tude: 

(1) Sea level pressure of 2116 pounds per 

square foot (76 centimeters mercury); 

(2) Ambient temperature of 77 degrees 

Fahrenheit (25 degrees Celsius); 

(3) Relative humidity of 70 percent; and 
(4) Zero wind. 
(b) 

Reference test site. The reference test 

site is flat and without line-of-sight obstruc-
tions across the flight path that encom-
passes the 10 dB down points of the A-weight-
ed time history. 

(c) 

Level flyover reference profile. The ref-

erence flyover profile is a level flight, 492 
feet (150 meters) above ground level as meas-
ured at the noise measuring station. The ref-
erence flyover profile has a linear flight 
track and passes directly over the noise 
monitoring station. Airspeed is stabilized at 
0.9V

H

; 0.9V

NE

; 0.45V

H

+ 65 kts (120 km/h); or 

0.45V

NE

+ 65 kts (120 km/h), whichever of the 

four airspeeds is least, and maintained 
throughout the measured portion of the fly-
over. Rotor speed is stabilized at the max-
imum normal operating RPM throughout the 
10 dB-down time interval. 

(1) For noise certification purposes, V

H

is 

defined as the airspeed in level flight ob-
tained using the minimum specification en-
gine power corresponding to maximum con-
tinuous power available for sea level pres-
sure of 2,116 psf (1,013.25 hPa) at 77 

°

F (25 

°

C) 

ambient conditions at the relevant max-
imum certificated weight. The value of V

H

 

and V

NE

used for noise certification must be 

included in the Flight Manual. 

(2) V

NE

is the never-exceed airspeed. 

(d) The weight of the helicopter shall be 

the maximum takeoff weight at which noise 
certification is requested. 

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