OF FLYOVER NOISE MEASURES FOR REPEXTED FLIGHTS OF AND

2. Government Accession No. 1. Report No. NASA CR-1752

4. Title and Subtitle

VARIABILITY OF FLYOVER NOISE MEASURES FOR REPEXTED FLIGHTS OF TURBOJET AND PISTON ENGINE TRANSPORT AIRCRAFT

3. Recipient's Catalog No.

5. Report Date

6. Performing Organization Code

March 1971

Bolt Beranek and Newman Inc. 15808 Wyandotte S t r e e t van N U ~ S , Ca l i forn ia 91406

7. Author(s)

Dwight E. Bishop

9. Performing Organization Name and Address

12. Sponsoring Agency Name and Address

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON, D. C. 20546

8. Performing Organization Report No.

10. Work Unit No.

126-61-14-01 11. Contiact or Grant No. .,

NAS1-8168

I 16. Abstract

13. Type of Report and Period Coverpd

Contractor Report

14. Sponsoring Agency Code

19. Security Classif. (of this report) Unclassif ied

I

15. Supplementary Notes

20. Security Classif. (of this page) 21. NO. of Pages 22. Price* Unclassif ied 37 $3.00

Various f lyover noise measures a r e reported f o r noise d a t a recorded at f i v e ground pos i t ions loca ted underneath and t o t h e s ide of t h e f l i g h t path during 20 cont ro l led l e v e l f l i g h t f lyovers of two a i r c r a f t , ( a four-engine p is ton a i rp lane and a four-engine t u r b o j e t a i rp lane) during one day of f l i g h t tests. Noise measures a r e compared t o show t h e degree of v a r i a b i l i t y among f lyover measurements during repeat runs or among measurements made a t d i f f e r e n t pos i t ions during t h e same flyover and t o show t h e degree of c o r r e l a t i o n between d i f f e r e n t f lyover noise measures. reported f lyover measures range from those der ived from simple frequency weighting networks, such as t h e A- or N-weighted sound l e v e l s , t o those computed from one-third octave band spec t ra such as t h e preceived noise l e v e l .

The

17. Key Words (Suggested by Author(s1)

Aircraf t Plyover noise Atmospheric noise absorpt ion

18. Distribution Statement

Unclassif ied - Unlimited

T a b l e 'I - LOG OF A ~ ~ ~ ~ A F T TEST IGHTS - 29 AP Table E'I - TYPICA TERS DURING

NASA, WALLOPS STATIO

PLIGHTS

Table PIP - SU ASTJRED FLYOVER NOISE MEASURES

*Tab le IV - SUMMA~Y 0 LINE ANALYSIS OF VARIOUS ASURES OF PLYOVER NOISE LEVELS

T a b l e V - COMPARISON OF V A R I ~ B I L ~ T ~ I N FLYOVER NOISE '

MEASURES FOR REPEAT FLYOVERS OF A ~ O U R - E ~ G ~ ~ ~ TURBOJET TRANSPORT AIRCRAFT

T a b l e VI - COMPARISON O F MEAN DIFFERENCES BETWEEN VARIOUS PLYOVER NOISE MEASURES

f V

LIST OF FIGURES

Figure 1 - LOCATIONS OF NOISE MEASUREMENT P O S I T I O N S WITH R E S P E C T TQ A I R C R A F T PATH

Figure 3 - SCHEMATIC O F DATA A N A L Y S I S

Figure 4 - A R I A T I O N I N E F F E C T I V E P E R C E I V E D N O I S E LEVE ( E P N L ) A S A F U N C T I O N OF ~ I N ~ ~ M SLANT D I S T A N C E

Figure 5 - V A R I A T I O N I N COMPOSPTE P E R C E I V E D N O I S E LEVELS F U N C T I O N OF M I N ~ ~ M SLANT D I S T A N C E

F igure 6 - V A R I A T I O N I N ~~I~~ P E R C E I V E D NOISE LEVELS (PNLM) AS A FUNCTION O F M I ~ I ~ ~ S L A N T D I S T A N C E

F igure 7 - V A R I A T I O N IN ~ A ~ I ~ U ~ XT-IfiEIGHTED SOUND LEVELS A F U N C T I O N OF IN^^^ SLANT D I S T A N C E

Figure 8 - V A R I A T I O N I N ~ A ~ I ~ ~ A-WEIGHTED SOUND L E V E L S AS A F U N C T I O N OF ~ I N I ~ M SLANT D I S T A N C E

F i g w e 9 - D I F F E R E N C E S BETWEEN E F F E C T I V E P E R C E I V E D N O I S E LEVELS AND C O M P O S I T E P E R C E I V E D N O I S E LEVEES A S A F U N C T I O N OF M r ~ ~ M ~ ~ S L A N T D I S T A N C E

F igure 10 - FLYOVER S I G N A L DURATION W I T H I N 10 dB O F T H E M A X I ~ M TONE-CORRECTED P E R C E I V E D N O I S E LEVEL A S A F U N C T I O N OF N I N I m N SLANT D I S T A N C E

VARIABILITY OF FLYOVER NOISE MEt-1STJ,W FOR REPEATh’89

FLIGHTS OF TURBOJET AND PISTON E N G I N 3 TRANSPORT AIRCRAFT

ght E . B%shop

Various f lyove r noise measures are repor ted data recorded a t f i v e ground p o s i t i o n s located underneath

t o the side of t h e f l i g h t pa th dur ing 20 con t ro l l ed eve1 f l i g h t f l yove r s of two a i r c r a f t , our-engine p i st on

a i r p l a n e and a four-eng ne t u r b o j e t a i r p l a n e ) during one day of f l i g h t t e s t s , Noise measums a r e compared t o s t h e degree of v a r i a b i l i t y anong f lyove r measurements during repeat runs or among measurements made a t d i f f e r e n t p o s i t i o n s during t h e same f lyove r and t o show t h e degree of c o r r e l a t i o n between d i f f e r e n t f lyover noise measures, The repor ted f lyover measures range from those der ived

om simple frequency weighting networks, such as t h e A- o r N-weighted sound l e v e l s , t o those computed from one- t h i r d octave band spec t r a such as the perceived noise l e v e l ,

The s c a t t e r i n d a t a about r eg res s ion l i n e s f i t t e d t o p l o t s of t h e var ious f lyove r noise measures as a funct ion

s l a n t d i s t a n c e d i d not show s i g n i f i c a n t d i f f e r e n c e s among t h e nofse measures, The s tandard dev ia t ions f o r Fneasu ments d i r e c t l y under the f l i g h t path during t h e seven f l y - overs of a t u r b o j e t a i r c r a f t a t 2000 f t a l t i t u d e ranged from 0.3 t o 0.6 d3, r e f l e c t i n g ra ther small v a r i a b i l i t y i n measurements. For a measurement p o s i t i o n 2000 f t t o t h e s i d e of the f l i g h t path, s tandard dev ia t ions increased t o 0,7 t o 1,l d B , i n d i c a t i n g an inc rease i n v a r i a b i l i t y slant d i s t a n c e . These s tandard dev ia t ions are appro one-half t o one-thfrd t h e s i z e of s tandard devia t fons f o ndiv idua l one-third octave band noise l e v e l measurements,

AL the A-weighted sound Pevef, expressed An dE3

d the signal duration, in seconds, is the time in hich the flyover signal is n 80 dB of" i t s

maximum value

D the integrated d u r a t i o n colrrectPon f o r the EBNL

k, = 2d

k - 0

antilog [ m % T '"CL] D = PO PQg 1 - PNLTM - 1 3

EPNL the effectfve perceived noise level expressed in EPNdB, and defined as EPNL = PMLTM + D, accord w i t h

k the number of half-second time Increments elapse

10 dB of i e s maxilmum value the time at hich the signal was first

- L (Id the I_ level calculated a t t h e ktk time increment

or the data reported herein, the integrated measures eye approx%mated JT the %OlaOW%ng sUEUlla t fOn? pPQC@SS

from noise levels measured at kalf-second intervals k = 2d

- L (in%> = 3.0 log 1 antflog C a -3 = o

3

eighted sound l e v e l as def ined i n Ref. 2 , expressed i n dB, Tt is related t o the D- sound l e v e l , DE, by NL E= DL 9 19

n t ) t h e t ime-Integrated N-level, .in which N-levels are i n t e g r a t e d over the f lyover s i g n a l du ra t ion

PNL the perceived noise l e v e l a t any i n s t a n t of time, expressed i n PNd3, and ca l cu la t ed I n accordance

i t h Fief, 3 .

PNLC the composite perceived noise l e v e l , ca l cu la t ed from the maximum one-third octave frequency band sound pressure l e v e l s occur r ing during a f lyove r , i r r e s p e c t i v e of t h e time a t which t h e maximum band l e v e l s occur

PNL the maximum value of the perceived no (PNL) that occurs during a f lyove r

PNLT the perceived noise l e v e l value ad jus ted f o r the presence of d i scPe te f requencies , i n accordance w i t h R e f .

P t h e maximum value o f t h e perceived noise l e v e l adjusted for d i s c r e t e f requencies (PNLT) that occurs d u r i n ~ a f lyover

b i d page ‘3

4

INTRODUCTION

n this study, co %sons of the no measuped on the ground ing a number of airc overs made by two aircraft during one day of testing ppovide information concerning two aspects of f yover noise measu ment an6 interpretation. The comparisons sho the degree of variability in aircraft flyover noise measurements during repeat runs or among measurements made at different ground positions during the same aircraft flyover, The variability which may be expected during repeat flyovers is a problem of specific concern in FAA noise standards for aircraft certification (Ref 4). For example, the certification requirements require 90% confidence limits t o be placed on the repeat measurements, Variability is also of concern In aircraft noise monitoring systems. Such variability is affected not only by such obvious factors as variability in aircraft performance and measurement errom but also by the fluctuations and variabillty in received ground signals due to the sound propagation characteristics of the atmosphere,

Comparisons of the variability of differences between several flyover noise measurements are also presented, In recent years a relatively large number of measures have been advocated for describing aircraft flyover nofse. These measures range from relatively simple freqerency- weighted measures of the maximum noise levels such as the A-level and N-level to measures which are calculated from detailed spectrum analysis of the flyover signal throughout the noise signal time history, as required in the com- putation of the EPNL, For many engineering purposes

and methods f o r describllng the nofse around operating afrfields) there s a need to know how ell one may

average noise level as determined from

hich may include the design of noise mon torang systems

estimate measures Involving relatfvely comp analysis OF computatfon from more shply-measured

The measurements discussed in this study uantities,

e dtarsjkng a single day during which meteorolog2cal csndit%ons ,if sumxnar zed only in terms of ground measurements of temperature, humidity and w nd, did not change significantly throughout the tests, Thus the degree o variability observed will be less than one would expect from sepeat measurements made under a wider range of meteorological conditions or over a longer time span

ving seasonal changes i p 1 weather conditions,

6

DESCRIPTION OF FIELD MEASUREMENTS

The f i e l d tests were ccnducted at NASA Wallops Island Sta"tO?-i , V i rg in i a on 29 A p r i l 3.969- The tests consfs"ced of" a morning set of' seven f lyove r s by a Pour-engine tu rboJe t t r a n s p o r t a i r c r a f t (Convair 880) and an af ternoon set of seven f lyove r s by the same a i r c r a f t , I n the af ternoon t were a l s o s i x f lyove r s by a fous-engine piston-powered t rans- po r t a i r c r a f t (Lockheed l o w ) * F l i g h t s of t h e t u ~ b o j e t t ranspoyt a i r c r a f t were made a t a l t i t u d e s of I500 f t and 2000 ft; p i s t o n t r a n s p o r t aircraft f lyove r s ere at abtitudets . of 700 and 1500 ft, The flight pa ths of t h e leve l F l fght f l yove r s were t racked along a major po r t ion of the f l f g h t t r a c k using a grcund-based Bell Aerosystem GSM-5 loCalEZer and pos i t i on ing u n i t , The pilots were i n s t r u e t e d t o accept some speed v a r i a t i o n i f necessary i n order t o hold eng%ne power and altitude constanL along t h e s t r a i g h t l i n e poreion of t h e f l i g h t track, Table I lists the ind8vidual f l i g h t s and b a s i c a i r c r a f t opepating parameters as repor ted by f l i g h t C P ~ W observa t ions ,

shown i n F ig , I , One p o s i t i o n was measured d i r e c t l y under t h e f l i g h t path and o the r p o s i t i o n s were loca ted a t var ious d i s t ances from t h e f l i g h t t r a c k ,

form i n Fig. 2 . Noise signals from each microphone were recorded on t w o channels of an FM tape recorder , one channe having conventional flat frequency response and t h e other channel conta in ing a low frequency de-emphasfs c i r c u i t The data repor ted he re in i s based upon a n a l y s i s of t ape channels recorded w i t h the flat fpequerncy response channel.

Meteorological measurements were made on s i t e a t t su r face p o s i t i o n s . In a d d i t i o n radiosonde DeasureRents of temperatupe and humfdtty were made a t i n t e r v a l s before an

Noise was recorded a t f i v e measurement p o s i t i o n s as

Noise roecording ins t rumenta t ion 5s ind ica ted i n block

7

following the flight to obtain measures o temperature humidity, and winds aloft, Surface temperature, humidity and winds are summarjezed in Table PI, Further descriptfons of the meteorological conditions are provided in Ref, 5.

Except for the high humidity the reported surface condftion generally met the meteorological. requirements f o r aircraft noise certification tests. Generally, conditions aloft also fell within the certification requirement with the exception of tne relative humidities in excess of 90% observed at the approximate altitude of 1200 ft during the afternoon flights. Also noted was a morning temperature . inversion which disappeared before the afternoon measurement s

8

DATA ANALYSIS

One-third octave band sound pressure levels were determined at 1/2 second intervals during the useful portions of the flyover noise signal. Figure 3 indicates the data reduction instrumentation in block form. Noise slgnals recorded on FM channels with conventfonal flat frequency response were played back into a Hewlett-Packard Real Time Audio Spectrum Analyzer, Under control of a Digital Equip- ment PDP-8 computer, the noise signals were analyzed by the Spectrum Analyzer at half-second intervals in one-third octave frequency bands extending from 50 Hz to 10,000 Hz center frequencies, Acoustic calibration signals recorded on the tape at the tine of 'the field experiment were utilized as a calibration standard f o r the noise signal. In addition, frequency response corrections for the record and playback systems were introduced i n t o the computer e

which noise spectra at half-second intervals were recorded in binary form. LaterS the paper tape was read i n t o the PDP-8 computer at which time various flyover noise measures w ~ r e calculated from the third octave band spectra. R number of the calculated flyover noise measures are presented in Table I11 for each flyover and measurement position for which valid data was obtained. The minimum slant distance (obtained from radap trackfng data) is also listed in the table, as are several measures of the duration of the signal wfthin 10 d B of the maximum flyover signal level,

The output of the PDP-8 computer was a paper tape in

* Several sets of measurements were excluded from t he table because of faulty recordings o r a fault in the data analysis b

9

The f lyover noise l e v e l measures t abu la t ed in Table

Measures dependent upon t h e frequency spectrum shape and maximum s i g n a l ampftude, This would include rneasupea derfved fyom a simple fY"equencgr network such as the A- o r N-level and $hose computed from third- octave band s p e c t r a g such as t h e PNL,

11% can be grouped Snto two general classes: (a)

(b) Measures dependent upon t h e time h i s t o r y of the flyover noise slegnals as well as the spectrum shape and s i g n a l ampftude. T h i s would inc lude t h e t ime-lnte- g ra t ed A- and N-levels and t h e e f f e c t f v e perceived noise level (EPNE) whfch, a lone of a11 t h e Ante- gra ted measures l i s t e d i n Table 911, Includes an adJustment f o r t he presence of d i s c r e t e f requencfes , (However, f o r t h e a i rc raf t and power s e t t i n g s used during t h e f lyove r s , d i s c r e t e components were not very s fgni f icant ,hence t h e EPNE va lues do not r e f l e c t any large corrections f o r t h e presence of d i s c r e t e frequene- l e s e )

The var ious t ime-integrated noise l e v e l s are genera l ly

where T i s an arbitrary normalizfng t i m e cons t an t J and where t (1) and t ( 2 ) are the l f m f ' c s of t h e t fme du ra t ion d during wRlch t h e - L is wL.thfn a specified value of the

maximum - L. For the data repor ted f n Table 111, t h e f n t e g r a t f o n

of Eq. (1) was replaced by a summation of noise leve ls de te rmhed a t half-second i n t e r v a l s over t h e f lyove r per iods i n which t h e noise l e v e l was withfn 1 0 dB of" t h e

10

maximum level, Thus, in the data analysis, Eq, (9) was replaced by:

L - k = 28

k = O

&L (q -3 antilog -- lo

where k is the number of half-second time increments elapsed from the time at which the signal was first within 10 dB of its maximum value. For the EPNL, T was taken as 10 seconds; f o r the integrated A- and N-levels, T was set a t one second,

Eq. (21, except with the summatfon extending over t h e top 20 dB of the signal envelope. In agreement w i t h previous analysis of flyover measupes (Ref,6 such measures, not r epor t ed , typically show small increases over va lues for 10 dB summation, with the fncreases typically ranging from

Integrated measures were also computed in accord with

o to 0 ~ 5 GIB,

FLYOVER NEASURE COMPARISONS

Figures 4 through 10 show selected portions of the flyover noise data tabulated in Table I11 plotted as a function of minimum slant distance, Shown are data for the EPNL - PNLC PNLM, AL, NL, and the quantity EPNL -PNLC e Also shown in Fig. 10 is the signal duration interpreted as the time within 10 dH of the maximum tone-corrected perceived noise level.

Shown in the figures are linear regression lines (noise levels vs, log (slant distance)) fitted by the method of least squares, Since one expects a linear as well as a logarithmic term in the curves relating noise levels with slant distance a more complex curve instead of a linear regression line might have been warranted had the data been obtained over a larger range of slant d l s -

tances. However, for these flyovers the range in slant distances was 2 t o 1 f o r the turbojet aircraft and slightly over 3 to 1 for the piston aircraft. Particularly fop the turboget aircraft data, this ratio of slant distances is not sufficient to accurately determine changes in noise levels as a function of s l a n t distance.

For the regression lines shown i n Figs. 4 through 9,Table IV lists the intercept at 1000 f t slant. distance and the slope indicated in d B per doubling of distance, The table a l s o lists the statistic S

indication of the degree of variability not accounted by the regression line fit to the data. (Ref. 7 ) . "

which provides an Y/X

For a large sample and assuming normal distributfon of levels about the true regression line, one would expect that 68% of the measured levels should lie within + s of the regression line, o r 95% should lie within - y/x J- 2 Sy,x"

12

a

One w i l l note that , except f o r t h e A-levels f o r the

e t f lyovers , t h e curves f o r measures which do not re f lec t s igna l d u r a t i o all have s lopes f t h i n a narrow range between 6 - 8 to 7 . 3 d B per doubling of d i s t a n c e , ever, t h e A-level measurement f o r t h e t u r b o j e t t r a n s p o r t a i r c r a f t shows a lesser s lope .

One would expect t h e curves f o r measures r e f l e c t i n g s i g n a l du ra t ion t o show smaller s lopes w i t h d i s t ance than measures not r e f l e c t i n g s i g n a l du ra t ion because of the inc rease i n s i g n a l du ra t ion w i t h s l a n t d i s t a n c e as ind ica t ed i n Fig. 1 0 . T h i s expect ion i s confirmed by t h e s lope of t h e r eg res s ion l i n e f i t t e d t o t h e EPNL data f o r t h e p i s t o n a i r c r a f t , but does not hold f o r t h e EPNL data f o r t h e t u r b o j e t a i r c r a f t . I n t h i s case , t h e EPNL vs PNEC data show an almost f l a t t r end wi th d i s t ance . It i s expected t h a t t h i s t r end f o r the EPNL data ( o r t h e maximum A-level measurements discussed above) would not be observed f o r f lyove r measurements taken over a greater range of s l a n t d i s t a n c e s .

measure given i n Table I V are genera l ly comparable values running from 0,8 t o 1 . 4 dB. Thus t h e scatter i n data about

Ho

of t h e f lyover Y/X

The values f o r t h e s t a t i s t i c S

the f i t t e d r eg res s ion l i n e d i d not appear t o be d r a s t i c a l l y d i f f e r e n t f o r any of the measures l i s t e d i n Table I V .

Aeother m a s u r e of v a r i a b i l i t y i n f lyover measures can be obtained by examining t h e d i f f e r e n c e s i n f lyover noise l e v e l s observed a t t h e same measurement p o s i t i o n during repeat runs of t h e a f r c r a f t a t t h e same nominal a l t i t u d e and f l i g h t condi t ions . T a b l e V l i s t s the mean values and s tandard dev ia t ions f o r seven f lyover measurements a t Pos i t i on 2 (under the a i r c r a f t ) a n d at Pos i t ion 5, f u r t h e s t from t h e a i r c r a f t f l i g h t pa th , Data are reported f o r t h e seven f l y o v e r s of t h e four-engine t u r b o j e t a i r c r a f t a t a nomfnal a l t i t u d e of 2000 f t . I n computing t h e values

reporqated in Table V t h e measured nofse levels reported in Table I11 have been adjusted fop minor differences In slant distances durfng different fayovers using the slope values glwm in Table IV.

The standam3 deviatlons i.eported f o r the various measures at Pos%tion 2 mnge from 0.3 t o 0 ,6 dB reflecting rather small variabflity I n repeat flyovers, The standard dev ia t onas calculated. f o r Position 5 measurements are somewhat largerg ranging from 0,q to 1.1 dB, reflecting an increase in variability as minimum slant distance is increased.

he standard deviations gIven in Table V may be compared with those of Table V of Ref, 5 which ape reported f o r sound levels measured in one-thfrd octave frequency bands dur ing portions of the same f'lyover signals, Such a comparison indicates t h a t the variability for the flyover measures of Table V are approximately one-half t o one- third the size of the standard deviations for the one-third octave band measurements.

given in Table do not indfcate large differences in variability among measures reflecting signal Integration or duration considerations, FOP the last four values listed in Table V, reflecting measurements not including duration conslderations, the composite perceived noise l e v e l indicates somewhat lower variability than the other measures,

of the flyover noise measures. Listed in Table VI are the mean difference between various noise level measures and the standard deviations f o r the differences. Three measuyes are compared w i t h the effective percefved noise level and two measures ape compaPed with the maximum pemefved nofse level

The standard deviations f o r the first four measures

Table VI lists the results of comparisons among several

14

I n addf t ion , two measures, t h e N-welghted and A- weighted noise l e v e l s , a r e compared w i t h t h e composite perceived no i se l e v e l , a very common measure of a i r - c r a f t no ise l e v e l s i n t h e l a s t few yea r s , The average d i f f e r e n c e s between t h e composite perceived noise l e v e l and A- o r H-weighted l e v e l s are i n good agreement w i t h t h e d i f f e rences repor ted e a r l i e r (Ref, 8) a

It i s I n t e r e s t i n g t o note t h a t t h e d i f f e rences between t h e e f f e c t i v e perceiver? noise level and the i n t e g r a t e d A-levels or i n t e g r a t e d N-levels a r e approximately t h e same as the d i f f e r e n c e s between t h e composite perceived noise l e v e l and t h e maximum A- o r N-levels.

The s tandard dev ia t ions l i s t e d i n Table V I f o r the d i f f e r e n c e s range from 0 . 2 dB t o a maximum of 0.8 dB. The d i f f e r e n c e s between t h e var ious simpler measures and t h e EPNL show standard devia t fons ranging from 0,3 t o 0,6 PNdB, an acceptably moderate degree of v a r i a b i l i t y f o r many f i e l d measurement purposes where high accuracy i s not r e q u i r e d i n es t imat ing t h e e f f e c t i v e perceived noise l e v e l , Comparisons of A-level o r N-weighted l e v e l s w i t h t h e ca l cu la t ed perceived noise l e v e l s (PNLC o r PNLM) show standard dev ia t ions ranging from 0 . 2 t o 0.8 dB again i n d i c a t i n g that t h e s impl i e r measures o f t e n provide very good es t imat ions of t h e more complex ca l cu la t ed measures

O f course, f o r measurements extended t o a wider v a r i e t y of a i r c r a f t , a i r c r a f t operatfng condl t fons, o r atmospheric condi t ions , g r e a t e r v a r i a b f l i t y among measures may be

expected, For example, t y p i c a l values repor ted prevfously f o r a r e l a t i v e l y wide range of j e t t r a n s p o r t a i r c r a f t show standard dev ia t ions of t h e oPder of 1 . 0 t o 2 . 0 dB f o r d f f f e renees between PNLC and A- o r N-weighted measupes,

REFERENCES

1.

2.

3 .

4,

5.

6 .

7 .

8.

S p e r r y , W i l l i a m C,: Aircraft Noise Evaluat ion. FAA Report FAA-~0-68-34~ Sept . 1958.

Anon: Frequency Weighting Network for Approximatfon of Perceived Noise Level f o r Aircraft Noise, SOC.

Automative Engr, ARP 1080, J u l y 1969.

Anon: D e f i n i t i o n s and Procedures for Computing t h e Perceived Noise Level of Aircraft Noise. SOC. Automative Engr, ARP 865A, August 1969.

Federal Aviat ion Regulat ions, P a r t 36: Noise Standards: A i r c r a f t Type C e r t i f i c a t i o n , 1969.

Bishop, Dwight E . and Simpson, Myles A . : Experimental Atmospheric Absorptfon Values from Aircraft Flyover Noise S igna l s . NASA CR-1751, 1971,

Bishop, Dwight E . : "Descr ipt ions of Flyover Noise S igna l s Produced by Various Je t Transport A i r c r a f t . " FAA Rpt. DS-67-18, August 1967.

C r o w , Edwfn E , ; Davisg Frances , ; and Maxfield, Margaret: S t a t i s t i c s Manual, Dover Pub l i ca t ions (New York), 1960,

Bishop, Dwight E , : "Judgments of t he Re la t ive and Absolute Accep tab i l i t y of Aircraft Nose." J. Acoust Soc, Am. , V o l e 40, No. 1, pp. 108-122, J u l y 1966,

16

TABLE I

NASA, WALLOPS STATION, VIRGINIA LOG OF AIRCRAFT TEST FLIGHTS - 29 APRIL 1969,

F l i g h t No.

111 112 113 114 115 116 117

211 212 213 214 215 21 6 217

221 222

223 2 24

225 226

Time EDST

0630 0639 0645 0652 0659 07 07 0714

1641 1648 16 55 1703 1710 17 18 17 28

1517 15 24 15 31 15 38 15 46 15 53

A l t f t

1500 1520 1530 1975 2050 2100 1500

1500 1550 1500 2200 2100 2050 2000

700 700 700 1500 1500 1500

IAS, Kn

208 205 205 204 202 205 2 03

21 0

198 208 208 204 205 208

220 220 220 220 220 220

A/C g r o s s W t , 1000 l b s

143.1 140.3 138.5 136.4 133.7 131.5 129.6

150 * 5 148.3 146.2 142.9 141.2 139.7 133.5

101.6 100.8 100 a 0

99.2 98.4 97.6

Engine S e t t i n g s

EPR 2.2 2.2 2.2 2.2 2.2 2.2 2.2

EPR 2.2 2.2 2.2 2.2 2.2 2.2 2.2

BMEP 234,2600 RPM

234,2600 234 , 2600 234,2600 234,2600 234,2600

T A B L E I1 T Y P I C A L S U R F A C E WEATHER PARAMETERS D U R I N G FLIGHTS

T i m e E D S T

0630 0720

1515 1600

1640 1730

0630 t o 1730

A/C

880

1049G

880

F l t No I

111- 117

221- 226

211- 217

Max Min

T e m p OF

58 58.5

61 59.5

59.5 59.5

70 57

R . H u m . %

100 100

85 88

88 80

100 67

Wind Speed, K n

Bar. Press Press i n Hg.

9.5 0

29.89 29 85

18

u m i 2 S a a

3 2 z z a a

L

c l a z z a a e m

m c l a z z & & w w

oolnln . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M L n O O 0Lnlnom olnmlno Lnlnoln o m 0 0 OOLnOLn lnolnlno olnor<ln ! n o L n m o m m m m l n l n w m m m w c o ln lnmmm e c m c r l m c m ~ c m m m ~ ~ w c m m w m m r l m e e l n u 3 w - c m n . m m c m r l drlrlri r lr l?IN rlrlrlrlrl r l r l r l r l m r l r l r l N rlrlrlN rlrlrlrlrl r lr lr lr lN rlrlrlrlrl r l r l r l r l w rlrirlrlN

o m 0 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . oolnln LnmlnlnLn m l n o o l n L n O M O m l n o o o o l n o m oolnlno OLnOLnO OLnlnlnln O O O L n O

f w m m =+-\DO l n = r m w m r -mmmo w m c a e c m ~ ~ r r m w r n l n w l n e ~ m w c - a t - w l n m w r l mmc-mN rlrldrl rlrlrlN rlrlrlrlrl r lr ldrlN rirlrlN r l r l d N rlrlrldrl r l i r l r l N rlrlridrl r l r l r l i N r l r l r l r lN

0 0 0 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . oolno oolnoo Lnolnoln Lnlnoo o o l n m o o m o l n l n o o l n m o o m o l n ooolno m o m m o f w m m m w w o w f l n w m m m m m m w e e = m m m w J - - ? J ~ o ~ ) a w m w r l m l n w w m w w c l n m o m w m ~ rfrlrld rlrlrlN rlrlrlrlrl rlrlrirlrl rlrlrlN r l r l r l N rlrlrlrirl r l r l 4 r l N rlrlrlrirl r lr lr lr lN N d r l r l N

m r l m m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . =roc-= t-=mmrf m c u w c f c m c u l n w w m ~ w = r c = r w wlnwc- ln r l m o o w l n a o w w - f m ~ m e w l n m ~ w m m a m w m = r m w f m ~ r l mmmrl mmNd l n w m = ~ --ft-wlnn.-f m c c - c - f ~?c-cln--f = J = ~ J N 0 0 0 0 0000 ooooo o o o o o 0000 0000 o o o o o o o o o c o o o o o o o o o o o o o o o r(rfrlrl rlrlrlrl rldrlrlrl rlrlrlrlrl rlrlrlrl rlrlrlrl rlrlrlrlrl rlrlrirl,- rlrfrlrld rlrlrlrlrl rlrlrlrld

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . t-w--?m t - l n ~ ~ o c w l n m m f m m r l l n i m r l m m m o c c w t n m w m c w ~ lnt-mmw c m m w = lnlnlnwm m m m m m m m m o m m m m m m m m m m o I m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m

rl

w m m r i O M ~ N ~ m m l n r l ~ r l r l m w o m m m -w=w m m m o m N - ~ N N rlclnrlt- --fmwmw ~ ~ m m m o m w l n - m a = m o m t - w o m w m m e w m m w w m ~ o r l m m l n m r l o m c m o o r l m m r l o m t - c c c - e m d o 0 0 4 0 0 0 r(r loo0 r l o o o o 0 0 0 0 0 0 0 0 r l r looo or l r loo orlr lr lo o r l r loo 0 0 0 0 0 rlrlrlrl rlrlrlrl rlrlrlrlrl rlrlrlrlrl rlrlrlri rlrlrlrl rlrlrlrlrl rlrlrlrlrl rlrlrlrlrl rlrlrlrlrl ridrlrlri

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

m w m r l c - w r n ~ cut-me03 c u m w m c m o m m WJJW m m c m f m=r=rcm o w w w m ~ 0 f - o r l m m f m o m w l n o m w = r m o m c - l n o t - w l n ~ w e w . . ) w w m N m o m c l n m r i o m w m o o o c m r l o m r - t-cccln r l o o o r l ooo r l r looo r i o o o o 0 0 0 0 0 0 0 0 or looo or l r loo orlr lr lo o r l r loo 0 0 0 0 0 rldrlrl rlrlrlrl rlrlrldrl rlrlrlrlrl rlrlrlrl rlrirld rldrlrlrl rlrlrlrlrl rlrlrfrlrl rlrlrlrlrl rirlrlrlrl

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

m c r l o W = O N w ~ > m l n m \ ~ m f o w mmm-1 c - - f w c ~ m ~ c u w ~ m c a m r l w m o l n e r l e ~ m l n c - o w m m c w J m c w m ~ m t - w f mwlnLnN lnln=~ mln f r l m m m c J m o m m m c m m o t - m o m m w \ ~ w c w - f 0 0 0 0 0 0 0 0 r l oooo 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o r l o o o ooor lo o r l ooo 0 0 0 0 0 rl-lrlrl rlrlrlrl rlrlrlrlrl rlrlrlrlrl rlrlrlrl rlrlrlrl rlrlrlrlrl rlrlrlrfrl rlrlrldrl rlrirlrlrl rlrlrlrlrl

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

t - m m y m m w = m m ~ o m ~ m e w m J M J = m t - m x m o m w w w m o m r l MOC\DW o x r l r n w o m w r n a o m w l n a m e ~ ~ o m m w r l m w w m w c w m w w l n ~ r l r l o m w m r l r i m t - m i r l r l m o r l r l m c - t - e m c n r l ooo r l o o o r l r looo r l o o o o 0 0 0 0 0 0 0 0 r l r l r loo o r l r loo orlr lr lo r l r l r loo 0 0 0 0 0 r l r l r l r + rlrlrlrl drlrlrlr( rlrlrlrlrl rlrldrl rlrlrlrl rlrlrlrlrl rlrlrlrlrl rlrlrlrlrl rlrlrldri rlrlrlrlri

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

W==J m m f m wc-lnrlm m c u c - f w w m d m 0 m t - m r l t - r l ~ ~ m?mt-m e m m w m ~ e ~ m t - m w m l n ~ m m w l n m m w f ~ m m t - l n o c w m m m w w m w w m m m m m c l n c o m m w coooc m o o m w wcccm 0 0 0 0 0 0 0 0 r l oooo r l o o o o 0 0 0 0 0 0 0 0 0 0 0 0 0 or looo or l r l r lo O r l ~ O O 0 0 0 0 0 rlrlrlrl rlrirlrl rlrlrldrl rlrlrlrlrl rlrlrlrl rlrlrlrl rlrlrlrlrl rlrlrlrlrl rlrlrlrlrl rlrlrlrld rlrlrlrlrl

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

rl J rl rl m rl N

N N N N rl

0 0 0 0 0 m m co m m m 0

W W m m m

0

m m 0 W 00

0

W m m cc

0

m m m

- i,

c u v

H H H

W rl

4 h

VI- m m alo E a

LnomLno OOOLnLn OOLnLnO OOLnOO LnooLn OLnOLn OLnOLnO o o o o m m m m l n m W N N W m r l t - m ~ n r l t-ooo=s m t - m w r l o m f t - m m m o t - m t - o w t-mmr-w w ~ L n m O r l N N r l N N r l r l r l N r l N N N N rl d r l N rl r l r l r l r l N r l r l r l N N r l r l r l r l m r l r l r l r l N

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LnLnOOLn LnmoLnLn o o o m l n OLnlnLnLn OOLnO LnLnlno L n o m m m Lnoooo LnoooLn

t - O a t - m a t - m w o m 0 o o ; T r l r u m w m r l m m m t - m m r l w m w o w m m m m m w m ~ m o r l N N d N r l r l r t r l w r l N N N N d d r l m d rld r l r l ~ d r l d w ~ r l d r l r l ~ r l r l r l d N

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

OOLnLnLn m o m o m LnlnlnoLn OOLnOO OOLnO OLnOO 0 0 m o L n oooom OOLnOln

r l o m W L n a t - w w r l m m m r l f r l t - ~ n m m rlarlt- t - m o r l L ~ N L ~ O W m ~ w m m W N O ~ O N N r l r l N r l r l r l r l N r l r l r l N N rl r l r l ~ rl r l r l r l c u ~ r l r l r l ~ ~ r l r l r l - 0 . r l r l r l r l m

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

OrlmOLn t - t - t -~o = r r y m m o m m f m o u d r l m ~ n r l - 7 ~ m o r l m r - rut- t - r l ~ t - w t - o f L n = r f N m f = r L n m f ~ n f f m m r l t - L n m mNt-Ln r l w ~ n m t - t - w m m ~ n t - m = r m wt-wLnf 0 0 0 0 0 ooooo o o o o o m o m m m m o m m o m m m m m m m m m m m m m m m m m m r l r l r l r l r l r l r ldr l r l r l r l r l r l r l r+ rl rl

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

r l ~ f ~ t - m r l o f r l m w w m o t - r l f = s m J ~ N O = m a r l m a r l r l o w o t - m ~ ~ r l m m r l w t - w w f tnt-t-t-LO w t - w w m r l r l o m m o f o m ~ m t - w o o m m t - m o m t - w m o m m t - r l r l r l r l r l d r l r l r l r l r l r l r l r l r l r l r l r loo r l r l r lo r l o o o r l r l ooo o r l o o o o r l o o 0 r l r l r l r l r l r l r l r l r f r l r l r l r l r l r l r l r l r l r l r l r l r l r ld r l d r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l d d

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

r l o r i ~ o w m m r u m w m t - o r l m w ~ n t - o m i u m m m m r l t - m o m r u m m r l o m m = r d m m m v)m=?wm f m r n m m ! n a = r t n m r l w m t - ~ o w m w Lnmr-m t - o w m m w m t - W N t - o m w f m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~ n ~ t - r l m = r r l O ~ m d ~ t - t - r l m m f o ~ o m m ~ n ~ f m ~ r u m m m o = r m m m c - wft-LnJ w t - w m ~ w m m o ~ n t - t - w w m - 1 m ~ o w m m m m m r l m w r l m o m w mNmmLn O N N m t - 0 0 0 0 0 o o o r l o ooooo o o o o m o o o m o o m m o o o m m m o m m m O O o m m r l r ldr l r l d r l r l r ld rlrlrldd r l r l r l r l r l r l r l r l r l r l r l r l rl r l r l d

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

= r m m ~ n m m I n P - f N t - m m m m m f m r i w o w r l m m m m m ~ m w r l m mmLnt-t- mLnLnNr-

w t - w t - ~ w t - t - m n WDCWWJ w m f ~ m m o m r + o m m m m f m r l m o f r l o m r l ~ ~ r l m o o o o o o o o o o ooooo o r l o o m or loo d o o m o o o o m o o o o m o o o o m r l r l r l r l r l r l r l r l r l r l drlrlrirl r l r l r ld r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

w r l m ~ m w ~ m r l m r lmr l t - r l m r l r l o m o w a f ~ ~ r l r l o m m ~ m J J ~ O L ~ m m r l m m m w ~ n t - m m t - ~ - m = r w w w ~ n ~ i n o m r l w f m m m o m o r - ~ m m m w m m o o w o m m m t - o o o o o o o o o o o o o o o o r l o o m o o o m d o o m o o m m m m o o o m o o o m m r l r l r l r l r l r l r l r l r l r l r l r l d r l r l r l r l r l r l r l r l r l rlrlrl r l r l r l r l r l r l r l r l

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

= s t - ~ m m f w m m ~ n o ~ n r u m r l m m m w r l ~ m q r l N O O ~ r l t - t - m m ~ w m m m m N o L n r - w t - t - m - f w m m o ~ n t-t-t-WJ r - r l f r l m m o ~ n d ~ f d m m m r l o r - d f N r l t - d m w o m ooooo o o o r l o o o o o o o r l o o m or loo d o o m o o o o m o o o o m o o o o m r l r l r l r l r l r l r l r l r l r l r l r l r l r l d r l r l r l r l rlrlrld r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

mLnmzrt- m f m t n m = r m m a t - O J W ~ O m m m m L ~ N ~ N w m t - 0 0 r l t n t - ~ m ~ o m r l m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . w t - w w f ~ n t - r - t - = r w t - w w ~ ~ w w o m ~ W N O w r l m m r l m o o m or loas o ~ r l o m 0 0 0 0 0 0 0 0 0 0 o o o o o o o o o m 0 0 0 0 o o m m o o o o m O O O m m o o o o m r l r l r l r l r f r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l r l rld r l r l r l r i r l r l r l r l r l r l r l

m ri N

W rl N

c- rl N

rl N N

J N N

m N N

N N N

ln N N

W N

N

r3

J 0 rl

m r3

f 0 rl

m u f 0 rl

m u f 0 rl

m 0

J 0 rl

=r 0 4

m 0 m m

0 0 m m m m

ul

0

a3

LIT I

M

r- I

M

t- I

ri

t- I

t-

I

O L n

d o . . I

v)J

r i d 0 d

. .

L n m Lnd rl d

. .

M C U

Lnd ri rl

. .

M cr) Jr i ri d

. .

J d

a d rl d

. .

J

cu

0

r- I

0

r- I

co v3

I

cu r-

1

Ln

a I

b a 3

M O . .

I

n o m r i cn . .

c O M

L n r l 0 r i

. .

c n c u

r - d 0 rl

. .

v 3 c u L o r i 0 ri

. .

m a 3 J O 0 rl

. .

21

r - r - l - i c o C o O r l d

0 0 d 0 O d d r - e * . . . . . .

r - c o w w c n c n c n m J J W c u J M J c u o r - o o o o o c n d r - d d d d d

. . D * l .

J = 3 - L n L n m m L n w

0 0 0 0 0 0 0 0 . * * * * .

d z PI w

A

c, c .ri

d 2

v

A

c, r: .rl

b=i 4

V E crl z PI 4 z

22

n a, 2 a, k a,

C k c d k a, .rl m El336

n

a, 0 c a, k a,

d G cdG a, .rl m zzna

m m v)

0 0 0 . .

a m 0 N O d

I

. .

= r L n v)

0 0 0 , .

b a 3 0

;Jrl 0 I .

c u m 0 0 . .

0 = r

d r l I d

e .

= r L n 0 0 . .

b u 3

o m ri

0 .

m v )

0 0 . .

c u m O N I d

. .

r-03 0 0 . .

d d zz, I 1

u u d d z z P i n

ln -c, d a,

5 2 2

k

cd

k a, > 0 h d r,

a3 cu c 0

U a, rn cd

I

4

a, -I-, 0 z

a

ln J-, r: aJ E a, k

cd 2 ; k a, 3 0 h d k

v) v)

r: 0

a a, %I cd

I

cu

m

23

8 d- o o U g .E

- 2 0 0 v)

0

0 C .-

-8 E

ij I-

-0 0 ce 0

E

cc

d- .- .- A

E o D

W

aJ

4- u)

c

.- z g 4-

X

t-

W P v, W [y:

U

r

3

Z 0

+ I

v)

- I- v)

P

I-

- 0

Z

I er r)+ v,q a*

W

W

W

c

u0 C

; 01-

; u) v)

D Z 0

24

NOTES: 1 e Microphone placed 1.2 m (5 ft) above ground with diaphragm

perpendicular to flight path e

2. High-pass filter, -36 dB atten at 100 Hz, -6 dB atten at 20 kHz. 3. Voice time synchronization signal (from central station) recorded

on separate channel

FIGURE 2 e T Y P I C A L FLYOVER NOISE MEASUREMENT INSTRUMENTATION

25

v)

v)

-I

- >.

Z 6 a a

a

I-

n

0 U

U

a 2

- l-

W I U v)

26

115

110

105

100

95 $00 600

115

110

1 05

1 00

95

800 1000 2000 4000 Minimum Slant Distance in feet

A. FOUR-ENGINE TURBOJET AIRCRAFT

$00 600 800 lOd0 2000 4000 Minimum Slant Distance in feet

B. FOUR-ENGINE PISTON AIRCRAFT

F IGURE 4 . V A R I A T I O N IN EFFECTIVE PERCEIVED N O I S F LEVELS ( E P N L ) AS A F U N C T I O N OF M I N I M U M S L A N T D I S T A N C E

27

120

m -0 iz 2 115 - P) > P) -I

I - 2 110 -0

> a, - E

5

Q

2 105 s Q

U

100 400 600 800 1000 2000 4000

Minimum Slant Distance in feet

A. FOUR-ENGIN€ TURBOJET AIRCRAFT

115

m -0 z .= 110 .- - 0 > -I

I 2 105 e-

-0

> P) - E

CL

P) 100 t Lo .- B s

95 400 600 800 1000 2000 4000



F IGURE 5 . V A R I A T I O N IN C O M P O S I T E PERCEIVED NOISE LEVELS ( P N L C ) AS A F U N C T I O N OF M I N I M U M S L A N T D I S T A N C E

28

115

110

105

1 00

95 400 600 800 1000 2000 4000



I15

I10

105

IO0

95 400 600 800 1000 2000 4000



F I G U R E 6 . V A R I A T I O N IN M A X I M U M P E R C E I V E D N O I S E LEVELS ( P N L M ) AS A F U N C T I O N O F M I N I M U M S L A N T D I S T A N C E

29

115

m W C - - m 110 > m -I

W C

0 v)

-8 105 2 P) - $ z

100 -

95

600 800 1000 2000 Minimum Slant Distance in feet


400 600 800 1000

4000

200 4000 .~~~


8. FOUR-ENGINE PISTON AIRCRAFT

FIGURE 7 . V A R I A T I O N I N M A X I M U M N - W E I G H T E D S O U N D LEVELS AS A F U N C T I O N OF M I N I M U M S L A N T D I S T A N C E

30

400 600 800 1000 2ooO Minimum Slant Distance in feet


100

95

90

85

80 _.

400 600 800 1000 200 4000 Minimum Slant Distance in feet


8. V A R I A T I O N IN M A X I M U M A - W E I G H T E D S O U N D LEVELS AS A F U N C T I O N O F M I N I M U M S L A N T D I S T A N C E

10

5

m U C - y o z z I

-I

W

-5

-1 0

10

5

0

-5

-1 0

400 600 800 1000 2000 Minimum Slant Distance in f e e t


400 600 800 1000 2000 Minimum Slant Distance in f e e t

4000

4000

B. ~ FOUR-ENGINE PISTON AIRCRAFT

FIGURE 9 . DIFFERENCES BETWEEN EFFECTIVE PERCEIVED NOISE LEVELS A N D C O M P U S i T E PERCEIVED NOISE LEVELS AS A

F U N C T I O N $OF M I N I M U M SLANT D I S T A N C E

32



10

8

6

4 400 600 81

M

0

1 1000 2000 4000 irnurn Slant Distance in feet


F I G U R E 10. F L Y O V E R S I G N A L D U R A T I O N W I T H I N 10dB O F THE

F U N C T I O N O F M I N I M U M S L A N T D I S T A N C E M A X I M U M T O N E - C O R R E C T E D PERCEIVED NOISE LEVEL AS A

OF FLYOVER NOISE MEASURES FOR REPEXTED FLIGHTS OF AND

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