Appendix B to Part 36 - Noise Levels for Transport Category and Jet Airplanes Under § 36.103
14:1.0.1.3.20.14.283.1.37 : Appendix B
Appendix B to Part 36 - Noise Levels for Transport Category and Jet
Airplanes Under § 36.103 Sec. B36.1
Noise Measurement and
Evaluation. B36.2
Noise Evaluation Metric. B36.3
Reference Noise Measurement Points. B36.4
Test Noise
Measurement Points. B36.5
Maximum Noise Levels. B36.6
Trade-Offs. B36.7
Noise Certification Reference
Procedures and Conditions. B36.8
Noise Certification Test
Procedures. Section B36.1 Noise measurement and evaluation
(a) The procedures of Appendix A of this part, or approved
equivalent procedures, must be used to determine noise levels of an
airplane. These noise levels must be used to show compliance with
the requirements of this appendix.
(b) For Stage 4 airplanes, an acceptable alternative to
paragraph (a) of this section for noise measurement and evaluation
is Appendix 2 to ICAO Annex 16, Volume I, Amendment 7 (Incorporated
by reference, see § 36.6).
(c) For Stage 5 airplanes, an acceptable alternative to
paragraph (a) of this section for noise measurement and evaluation
is Appendix 2 to ICAO Annex 16, Volume 1, Amendment 11-B
(Incorporated by reference, see § 36.6).
Section B36.2 Noise Evaluation Metric
The noise evaluation metric is the effective perceived noise
level expressed in EPNdB, as calculated using the procedures of
appendix A of this part.
Section B36.3 Reference Noise Measurement Points
When tested using the procedures of this part, except as
provided in section B36.6, an airplane may not exceed the noise
levels specified in section B36.5 at the following points on level
terrain:
(a) Lateral full-power reference noise measurement point:
(1) For jet airplanes: The point on a line parallel to and 1,476
feet (450 m) from the runway centerline, or extended centerline,
where the noise level after lift-off is at a maximum during
takeoff. For the purpose of showing compliance with Stage 1 or
Stage 2 noise limits for an airplane powered by more than three jet
engines, the distance from the runway centerline must be 0.35
nautical miles (648 m). For jet airplanes, when approved by the
FAA, the maximum lateral noise at takeoff thrust may be assumed to
occur at the point (or its approved equivalent) along the extended
centerline of the runway where the airplane reaches 985 feet (300
meters) altitude above ground level. A height of 1427 feet (435
meters) may be assumed for Stage 1 or Stage 2 four engine
airplanes. The altitude of the airplane as it passes the noise
measurement points must be within + 328 to −164 feet (+100 to −50
meters) of the target altitude. For airplanes powered by other than
jet engines, the altitude for maximum lateral noise must be
determined experimentally.
(2) For propeller-driven airplanes: The point on the extended
centerline of the runway above which the airplane, at full takeoff
power, reaches a height of 2,133 feet (650 meters). For tests
conducted before August 7, 2002, an applicant may use the
measurement point specified in section B36.3(a)(1) as an
alternative.
(b) Flyover reference noise measurement point: The point on the
extended centerline of the runway that is 21,325 feet (6,500 m)
from the start of the takeoff roll;
(c) Approach reference noise measurement point: The point on the
extended centerline of the runway that is 6,562 feet (2,000 m) from
the runway threshold. On level ground, this corresponds to a
position that is 394 feet (120 m) vertically below the 3° descent
path, which originates at a point on the runway 984 feet (300 m)
beyond the threshold.
Section B36.4 Test noise measurement points.
(a) If the test noise measurement points are not located at the
reference noise measurement points, any corrections for the
difference in position are to be made using the same adjustment
procedures as for the differences between test and reference flight
paths.
(b) The applicant must use a sufficient number of lateral test
noise measurement points to demonstrate to the FAA that the maximum
noise level on the appropriate lateral line has been determined.
For jet airplanes, simultaneous measurements must be made at one
test noise measurement point at its symmetrical point on the other
side of the runway. Propeller-driven airplanes have an inherent
asymmetry in lateral noise. Therefore, simultaneous measurements
must be made at each and every test noise measurement point at its
symmetrical position on the opposite side of the runway. The
measurement points are considered to be symmetrical if they are
longitudinally within 33 feet (±10 meters) of each other.
Section B36.5 Maximum Noise Levels
Except as provided in section B36.6 of this appendix, maximum
noise levels, when determined in accordance with the noise
evaluation methods of appendix A of this part, may not exceed the
following:
(a) For acoustical changes to Stage 1 airplanes, regardless of
the number of engines, the noise levels prescribed under § 36.7(c)
of this part.
(b) For any Stage 2 airplane regardless of the number of
engines:
(1) Flyover: 108 EPNdB for maximum weight of 600,000 pounds or
more; for each halving of maximum weight (from 600,000 pounds),
reduce the limit by 5 EPNdB; the limit is 93 EPNdB for a maximum
weight of 75,000 pounds or less.
(2) Lateral and approach: 108 EPNdB for maximum weight of
600,000 pounds or more; for each halving of maximum weight (from
600,000 pounds), reduce the limit by 2 EPNdB; the limit is 102
EPNdB for a maximum weight of 75,000 pounds or less.
(c) For any Stage 3 airplane:
(1) Flyover.
(i) For airplanes with more than 3 engines: 106 EPNdB for
maximum weight of 850,000 pounds or more; for each halving of
maximum weight (from 850,000 pounds), reduce the limit by 4 EPNdB;
the limit is 89 EPNdB for a maximum weight of 44,673 pounds or
less;
(ii) For airplanes with 3 engines: 104 EPNdB for maximum weight
of 850,000 pounds or more; for each halving of maximum weight (from
850,000 pounds), reduce the limit by 4 EPNdB; the limit is 89 EPNdB
for a maximum weight of 63,177 pounds or less; and
(iii) For airplanes with fewer than 3 engines: 101 EPNdB for
maximum weight of 850,000 pounds or more; for each halving of
maximum weight (from 850,000 pounds), reduce the limit by 4 EPNdB;
the limit is 89 EPNdB for a maximum weight of 106,250 pounds or
less.
(2) Lateral, regardless of the number of engines: 103 EPNdB for
maximum weight of 882,000 pounds or more; for each halving of
maximum weight (from 882,000 pounds), reduce the limit by 2.56
EPNdB; the limit is 94 EPNdB for a maximum weight of 77,200 pounds
or less.
(3) Approach, regardless of the number of engines: 105 EPNdB for
maximum weight of 617,300 pounds or more; for each halving of
maximum weight (from 617,300 pounds), reduce the limit by 2.33
EPNdB; the limit is 98 EPNdB for a maximum weight of 77,200 pounds
or less.
(d) For any Stage 4 airplane, the flyover, lateral, and approach
maximum noise levels are prescribed in Chapter 4, Paragraph 4.4,
Maximum Noise Levels, and Chapter 3, Paragraph 3.4, Maximum Noise
Levels, of the International Civil Aviation Organization (ICAO)
Annex 16, Environmental Protection, Volume I, Aircraft Noise, Third
Edition, July 1993, Amendment 7, effective March 21, 2002.
[Incorporated by reference, see § 36.6].
(e) For any Stage 5 airplane, the flyover, lateral, and approach
maximum noise levels are prescribed in Chapter 14, Paragraph 14.4,
Maximum Noise Levels of ICAO Annex 16, Volume I, Amendment 11-B
(Incorporated by reference, see § 36.6).
Section B36.6 Trade-Offs
Except when prohibited by sections 36.7(c)(1) and
36.7(d)(1)(ii), if the maximum noise levels are exceeded at any one
or two measurement points, the following conditions must be
met:
(a) The sum of the exceedance(s) may not be greater than 3
EPNdB;
(b) Any exceedance at any single point may not be greater than 2
EPNdB, and
(c) Any exceedance(s) must be offset by a corresponding amount
at another point or points.
Section B36.7 Noise Certification Reference Procedures and
Conditions
(a) General conditions:
(1) All reference procedures must meet the requirements of
section 36.3 of this part.
(2) Calculations of airplane performance and flight path must be
made using the reference procedures and must be approved by the
FAA.
(3) Applicants must use the takeoff and approach reference
procedures prescribed in paragraphs (b) and (c) of this
section.
(4) [Reserved]
(5) The reference procedures must be determined for the
following reference conditions. The reference atmosphere is
homogeneous in terms of temperature and relative humidity when used
for the calculation of atmospheric absorption coefficients.
(i) Sea level atmospheric pressure of 2116 pounds per square
foot (psf) (1013.25 hPa);
(ii) Ambient sea-level air temperature of 77 °F (25 °C,
i.e., ISA + 10 °C);
(iii) Relative humidity of 70 per cent;
(iv) Zero wind.
(v) In defining the reference takeoff flight path(s) for the
takeoff and lateral noise measurements, the runway gradient is
zero.
(b) Takeoff reference procedure:
The takeoff reference flight path is to be calculated using the
following:
(1) Average engine takeoff thrust or power must be used from the
start of takeoff to the 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 engines with a bypass
ratio of 2 or more and for Stage 3 airplanes, the following
apply:
(A): For airplanes with more than three engines - 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 following, 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 lateral 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 before August 7, 2002, a single reference flight
path that includes thrust cutback in accordance 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 selected by the applicant for use in normal
operation; 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
airplanes, the test day speeds and the acoustic day reference speed
are the minimum approved value of V2 + 35 knots, or the
all-engines-operating speed at 35 feet, whichever speed is greater
as determined under the regulations 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 reference
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 retracted. Configuration means
the center of gravity position, and the status of the airplane
systems that can affect airplane performance or noise. Examples
include, the position 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 average of all the
certification compliant engines used during the airplane flight
tests, up to and during certification, when operating within the
limitations and according to the procedures given in the Flight
Manual. This will determine the relationship of thrust/power to
control parameters (e.g., N1 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 approach speed of Vref + 10
kts (Vref + 19 km/h) with thrust and power stabilized must be
established and maintained over the approach measuring point. Vref
is the reference landing speed, which is defined as the speed of
the airplane, in a specified landing configuration, at the point
where it descends through the landing screen height in the
determination of the landing distance for manual landings. For
Concorde airplanes, a steady approach speed that is either the
landing reference speed + 10 knots or the speed used in
establishing the approved landing distance under the airworthiness
regulations constituting the type certification basis of the
airplane, 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 reference procedure;
(4) The weight of the airplane at touchdown must be the maximum
landing weight permitted in the approach configuration defined 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 appendix 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 measurements must be conducted
and processed in an approved manner to yield the noise evaluation
metric EPNL, in units of EPNdB, as described in appendix A of this
part.
(c) Acoustic data must be adjusted to the reference conditions
specified in this appendix using the methods described in appendix
A of this part. Adjustments for speed and thrust must be made as
described in section A36.9 of this part.
(d) If the airplane's weight during the test is different from
the weight at which noise certification is requested, the required
EPNL adjustment may not exceed 2 EPNdB for each takeoff and 1 EPNdB
for each approach. Data approved by the FAA must be used to
determine the variation of EPNL with weight for both takeoff and
approach test conditions. The necessary EPNL adjustment for
variations in approach flight path from the reference flight path
must not exceed 2 EPNdB.
(e) For approach, a steady glide path angle of 3° ±0.5° is
acceptable.
(f) If equivalent test procedures different from the reference
procedures are used, the test procedures and all methods for
adjusting the results to the reference procedures must be approved
by the FAA. The adjustments may not exceed 16 EPNdB on takeoff and
8 EPNdB on approach. If the adjustment is more than 8 EPNdB on
takeoff, or more than 4 EPNdB on approach, the resulting numbers
must be more than 2 EPNdB below the limit noise levels specified in
section B36.5.
(g) During takeoff, lateral, and approach tests, the airplane
variation in instantaneous indicated airspeed must be maintained
within ±3% of the average airspeed between the 10 dB-down points.
This airspeed is determined by the pilot's airspeed indicator.
However, if the instantaneous indicated airspeed exceeds ±3 kt
(±5.5 km/h) of the average airspeed over the 10 dB-down points, and
is determined by the FAA representative on the flight deck to be
due to atmospheric turbulence, then the flight so affected must be
rejected for noise certification purposes.
Note:
Guidance material on the use of equivalent procedures is
provided in the current advisory circular for this part.
[Amdt. 36-54, 67 FR 45235, July 8, 2002; Amdt. 36-24, 67 FR 63196,
Oct. 10, 2002; 68 FR 1512, Jan. 10, 2003; Amdt. 36-26, 70 FR 38749,
July 5, 2005; FAA Doc. No. FAA-2015-3782, Amdt. No. 36-31, 82 FR
46131, Oct. 4, 2017]