曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
the same angle 9 with theirflight paths. This assumption
of constant angle 0 .k one which may not be valid in all
cases. Future refinement shall be sought. Howevel:
for the present application of this test procedure, any
dfferences are considered small.
h) Position R represents the point on the measured take-of
jlight path nearest the noise measuring station K, and
R, is the corresponding position on the correctedflight
path. The minimum distance to the measured and corrected
flight paths are indicated by the lines KR and
KR,, respectively, which are normal to their flight paths.
If two peak values of PNLT are observed during flyover which
differ by less than 2 TPNdB that noise level which, when
corrected to reference conditions, gives the greater value shall
be used in the computation for EPNL at the reference
conditions. In that case the point corresponding to the second
peak shall be obtained on the corrected flight path by applying
manufacturer's approved data.
9.3 Approach profiles
a) Figure A1-7 illustrates a typical approach profile. The
beginning of the noise certijication approach profie is
represented by aeroplane position G whose vertical projection
on the flight track (extended centre line of the
runway) is point P. The position of the aeroplane is
recorded for a distance OPfrom the runway threshold 0
of at least 7.4 km (4 Nw.
b) The aeroplane approaches at an angle q, passes vertically
over the noise measuring station N at a height of
NH, begins the level-ofat position I, and touches down
at position J.
c) The approach profile is defined by the approach angle q
and the height NH which arefinctions of the aeroplane
operating conditions controlled by the pilot. I f the
measured approach profile parameters are d~flerent
3om the corresponding reference approach parameters
(Figure A1-a), correcfions ure applied to the EPNL
calculatedhm the measured data.
d) Figure AI-9 illustrates portions of the measured and
reference approach flight paths including the signijicant
geometrical relationships influencing sound propagation.
GI represents the measured approach path with
approach angle rl, and G,.lr represents the reference
approach flight path at reference altitude and the
reference approach angle qr.
e) Position S represents the aeroplane location on the
measured approach flight path for which PNLTM is
observed at the noise measuring station N, and S, is the
corresponding position on the reference approach flight
path. The measured and corrected noise propagation
paths are NS and NS, respectively, which form the
same angle h with theirflight paths.
j) Position T represents the point on the measured
approach flight path nearest the noise measuring station
N, and T, is the corresponding point on the reference
uppruuch flight path. The minimum distances to the
measured and reference flight paths are indicated by the
lines NT and NT,, respectively, which are normal to
their flight paths.
9.4 PNLT corrections
9.4.1 Whenever the ambient atmospheric conditions of
temperature and relative humidity differ from the reference
conditions and/or whenever the measured take-off and
approach flight paths differ fkom the reference flight paths
respectively, corrections to the EPNL values calculated fkom
the measured data shall be applied. These corrections shall be
calculated as described below:
9.4.1.1.1 Referring to a typical take-off flight path shown
in Figure A1-6, the spectrum of PNLTM observed at station K,
for the aeroplane at position Q, shall be decomposed into its
individual SPL(i) values. A set of corrected values shall be
computed as follows:
SPL(i), = SPL(i) + 0.01 [a(i) - a(i),] KQ
+ 0.01 a(i), (KQ - KQ,)
+ 20 log (KQIKQ,)
-the term 0.01 [a(i) - a(i),] KQ accounts for the
effects of the change in atmospheric sound absorption
where a(i) and a(i), are the sound absorption
coefficients for the test and reference conditions respectively
for the i-th one-third octave band and KQ is the
measured take-off noise path;
- the term 0.01 a(i), (KQ - KQ,) accounts for the effect of
atmospheric sound absorption on the change in the noise
path length, where KQ, is the corrected take-off noise path;
and
-the term 20 log (KQJKQ,) accounts for the effects of
the inverse square law on the change in the noise path
length.
2411 1105 APP 1-28
Appendix I Annex I6 - Environmental Protection
F
A
I = I L
w w
K M
Take-off measurement distance
4 b
4
11 km minimum
b
Figure A1-4. Measured take-off profile
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
附件16--环境保护an16_v1_4ed(44)
