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N A T I 0 N A L
T R A N S P 0 R T A T I 0 N
S A F E T
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File No. 1-0010
AIRCRAFT INCIDENT REPORT TRANS WORLD AIRLINES
Boeing 707, N6729TW and AMERICAN AIRLINES Boeing 707, N8432
Near Phil l ipsburg, Pennsylvania June 11,1971
Adopted: DECEMBER 29,1971
I ~
NATIONAL TRANSPORTATION SAFETY BOARD Washington, D. C. 20591
REPORT NUMBER: NTSB-AAR-72-7
TECHNICAL REPORT STANDARD TITLE PAGE Report No.
T i t l e and S u b t i t l e Aircraft Incident Report - Trans World Air l ines Boein3 December 29, 1971 707, ~ 6 7 2 9 1 ~ and American Airlines Boeing 707, N8432 6.Performing Organizat ion Near Philipsburp Pennsylvania, June 11, 1971 Code Author(s) 8.Performing Organizat ion
NTSB-AAR-72-7 . 2.Government Accession No. 3 .Rec ip ient 's Catalog NO. 1
5.Report Date
Report No.
Performing Organizat ion Name and Address i0.Work U n i t No. Bureau of Aviation Safety National Transportation Safety Board 11.Contract o r Grant No. Washington, D. C . 20591 '
13.Type o f Report and Per iod Covered
Aircraft Incident .Sponsoring Agency Name and Address
NATIONAL TRANSPORTATION SAFETY BOARD dlshington, D. C. 20591
Report, June 11, 19-0
I .Supplementary Notes
.Abstract
Boeing 707, N8432, narrowly avoided a midair collision a t approximately 35,000 feel near Philipsburg, Pennsylvania, on June 11, 19'71, while operating wi th in positive control airspace under the control jurisdiction of the New York A i r Route Traffic Control Center. A s a result of the violent evasive maneuver executed by the captain of the 1WA B-707, three passengers and the f l ight engineer incurred minor injuries, but did not require m e d i a t e medical attention. None of the occupants of the other aircraft, whose crew was unaware of the occurrence un t i l some time
proceeded routinely t o their respective destinations. The National Transportation later, was injured. There was no damage to either aircraft , both of which
Safety Board determines that the probable cause of t h i s incident was the control- l e r ' s misidentification of the radar target o f 1W Flight 31, 86729~w, due t o a transitory diversion of attention t o another portion of the radar display. This resulted i n inappropriate t raff ic control actions with respect t o the American Airlines aircraft and placed the two f l ights on a collision course a t t he same altitude.
A Trans World Airlines (TWA) Boeing 707, N6729W, and an American Airlines
I . Key Words 1 8 . D i s t r i b u t i o n Statement
Released to Public.
Unlimited Distribution.
positive control airspace, violent evasive maneuver, minor injuries, misidentification-radar target, transitory diversion of attention.
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TRANS WORLD AIRLm BOEIIiG 707, ~ 6 7 2 9 ~ ~ AND
AMERICAm AIRLIWES BOEIIiG 707, N8432 NEAR EJHILIPSWIRG, PENNSYLVANIA, JUNE 11, 19n
TABLE OF CONTENTS
Synopsis ........................................... Investigation ......................................
ATC Handling of TW 31 ......................... ATC Handling of AAl5l ......................... ATC Handling of N940BS ........................
Analysis ........................................... Probsble Cause ..................................... Recommendation .....................................
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- - - - -_- _ _ _ _ _ _ S P E C I A L N O T I C E
Th i o r t s r e p cc m t a i n s t h e e s s e n t i a l i tems of in forma I t i o n r e v e l a n t t '0
t h e p r o b a b l e causes and s a f e t y messages t o be d e r i v e d from t h i s i n c i d e n t .
However, for t h o s e h a v i n g a need fo r more d e t a i i e d i n f o r m a t i o n , t h e o r i -
g i n a l f a c t u a l r e p o r t on t h e i n c i d e n t i s on f i l e i n t h e Washington o f f i c e
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Requests f o r r e p r o d u c t i o n shou ld be forwarded t o t h e :
NATIONAL TRANSPORTATION SAFETY BOARD O f f i c e o f General Manager A c c i d e n t I n q u i r i e s & Records S e c t i o n Washington, D. C. 20591
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File No. 1-0010
NATIONAL TRANSPORTATION SAFETY BOARD
AIRCRAFT INCIDENT REPORT WASHINGTON, D. C. 20591
Adopted: December 29, 1971
TRANS WORLD AIRLINES BOEING 707, ~ 6 7 2 9 ~ ~ AND
AMERICAN AIRLINES BOEING 707, N8432 NEAR PHILIPSBIRG, PENNSYLVANIA, JUNE 11, 1971
SYNOPSIS
A Trans World Airlines (TWA) Boeing 707, ~6729131, and an American Airlines Boeing 707, N8432, narrowly avoided a midair collision at approximately 35,000 feet near Philipsburg, Pennsylvania, on June 11, 1971, while they were operating within positive control airspace under the control jurisdiction of the New York Air Route Traffic Control Center. As a result of the violent evasive maneuver executed by the captain of the TWA 8-707, three passengers and the flight engineer incurred minor injuries. None of the occupants of the other aircraft, whose crew was unaware of the occurrence until some time later, was injured. There was no damage to either aircraft, both of which proceeded routinely to their respective destinations.
probable cause of this incident was misidentification by a New York The National Transportation Safety Board determines that the
Center controller of the radar target of Tw Flight 31, which resulted in inappropriate control action in respect to AA Flight 151 and which placed the two flights on a collision course at the same altitude.
The Safety Board recormends that:
The Federal Aviation Administration take appropriate action to assure that all air traffic control personnel are made aware of this misidentification incident so
the recurrence of similar incidents. that increased vigilance may result and serve to preclude
,
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INVESTIGATION
Trans World Airl ines ~ 6 7 2 9 , Fl ight 31, (W31) was a regularly
Francisco, California. The a i r c r a f t departed t h e gate a t 0930, on scheduled passenger f l i g h t between Philadelphia, Pennsylvania, and San
an instrument f l i g h t ru les (IF'R) clearance "as f i l e d , Limerick four departure, f l i g h t plan route, maintain 8,000, expect Fl ight L w e l (FL) 350 after Pottstown." Takeoff was a t 1002, and t h e f l i g h t was subse-
heading of 330 degrees, then d i rec t t o Philipsburg (PSB) and on up t o quently cleared t o climb t o 17,000 f e e t , then FL230, then ~ ~ 2 6 0 on a
FL350.
As f l i g h t neared PSB it was ins t ructed by t h e New York A i r Route Traff ic Control Center (Ny CNTR) t o contact Cleveland Center. A t t h i s point t h e f irst o f f i c e r was f ly ing t h e a i r c r a f t , and when they were about 9.5 naut ica l miles eas t of PSB i n l e v e l cru ise a t F'L350, t h e
Airl ines B-707 approximately 500 f e e t away and s l i g h t l y above, f ly ing captain saw t h e f irst o f f i c e r ' s windshield "fill" with an American
approximately 90" t o t h e l e f t of TW3l's course. The captain reacted ins tan t ly by pushing forward on t h e yoke. He estimated that the
i. . c l m s t p o i n t of approach of the two a i r c r a f t was 50 f e e t . 4
f l i g h t engineer of TW31 incurred minor in ju r i es . As a r e s u l t of the evasive maneuver, three passengers and the
American Airl ines N8432, Fl ight 151 (AAl5l), was a regularly scheduled passenger f l i g h t between Boston, Massachusetts, and Honolulu, Hawaii, with an intermediate stop i n S t . Louis, Missouri. The f l i g h t departed a t 0937 and was proceeding a t FL350 along J49 between Hancock, N.Y.,and Philipsburg (PSB) when the IVY CWTR directed the f l i g h t t o tu rn lef t t o a heading of 1%" and t o change t o another Ny CNTR frequency. Communications were established on t h e new frequency a t 1024 and t h e captain (who was handling communications while t h e f irst o f f i ce r was
then asked whether t h e vector was f o r spacing behind t ra f f ic and, a f t e r f ly ing t h e a i r c r a f t ) reported turning t o t h e new heading a t FL350. He
receiving an aff irmative reply, requested a clearance t o climb t o FL390. The contro l ler was unable t o authorize t h e requested a l t i t u d e because of t r a f f i c "at (FL) 370 r i g h t with you."
1026:45 was ins t ructed t o maintain a 270' heading t o in tercept 578 ( the planned route of f l i g h t a f t e r PSB).
AA15l was then cleared t o proceed d i rec t t o PSB (a t lO25:35) and a t
2f Fi led f l i g h t plan route was via Limerick Four Standard Instrument All times used herein are eastern stanchrd, based on t h e 24-hour clock.
Departure (SID), Penn Valley t r ans i t ion , d i rec t Philipsburg, J e t Route P (J) 60 Cleveland, 534 Carleton, Michigan, 5584 Northbrook, I l l i n o i s , as€ 594 Stockton, California, d i rec t San Francisco.
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A t 1028, TW3l reported NY CNTR that they had nearly h i t AAl5l. This report was t h e f irst knowledge that any of AAl5l's crew had of t h e occurrence. The f l i g h t s subsequently communicated with one another on 129.5MEz., a f t e r they had changed t o t h e Cleveland Center frequency fo r
without fur ther incident. t r a f f i c control purposes. Both f l i g h t s proceeded t o t h e i r dest inat ions
Sector 3 of t h e New York A i r Route Traff ic Control Center was responsible fo r t r a f f i c control i n the airspace within which t h i s in- cident occurred. The personnel assigned t o Sector on June 11, 1971, were: a developmental radar contro l ler (R3T) y, a monitor contro l ler
radar handoff contro l ler (H3), and a sec tor coordinator. responsible f o r t h e act ions of t h e developmental contro l ler (RW), a
ATC HANDLING OF TW31
s t r a t i f i e d i n t o th ree layers , with each Subsector having i ts own set The Cleveland Center Sector which adjoins NY CNTR Sector 3 is
of control lers physically displaced from each of t h e other Subsectors. The a l t i tudes which they control and the appropriate beacon code
i assignments f o r t h e i r t r a f f i c are :
Name of Subsector Altitudes - Code
Lorain Brecksville Clarion
FL350 - ~ ~ 6 0 0 2300 F'L240 - F'L330 2100 Up t o and
including FU3O 1300
~ ~ 6 0 0 i s a l l contained within Sector '3 and the re a r e no Subsectors. On the NY CNTR s i d e of t h e boundary, t h e airspace from m i 8 0 up t o
The three aforementioned beacon codes a r e employed on t h e same a l t i t u d e basis. Aircraf t operating between FL180 and FL230 use code 1300; between -40 t o FL330, code 2100; and t r a f f i c abwe that level , code 2300.
A t 1024:25 t h e NY radar handoff contro l ler attempted a handoff of TW3l t o t h e Cleveland Center. A t that time t h e a i r c r a f t ' s t a r g e t was 20 miles eas t of PSB. The receiving contro l ler i n Cleveland s t a ted that he
Tw3lwas r i g h t on t h e airway and his Cleveland counterpart responded: did not see t h e t a rge t . The radar handoff contro l ler i n NY repl ied that
Cleveland Center establ ished radar contact with TW3l. A t 1026:05, t h e NY "Wait a minute, the re ' s a guy c d n g on now . . . . ' I A t that point t h e
developmental radar contro l ler ins t ructed D l 3 1 t o contact Cleveland Center on 133.3MHz.
9 A contro l ler i n t r a in ing s t a t u s a s far as the posi t ion t o which he i s assigned i s concerned.
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A t 1026:15 ~ ~ 3 1 contacted Cleveland's Lorain Subsector radar
midair co l l i s ion and was advised of the f l i g h t ident i f ica t ion of t h e contro l ler and reported a t FL350. The captain then reported the near
American Airl ines B-707. The occurrence was reported by t h e Cleveland Sector coordinator t o t h e NY CNTR radar handoff contro l ler , who, i n turn, asked that TW3l be returned t o NY CNTR frequency f o r a minute. This was approved and t h e Cleveland radar control ler ins t ructed TW31, "change back t o t h e NY CNTR on 127.95 and t e l l them about t h e evasive act ion you had t o take. They had both airplanes ." iden t i f i ca t ion fea ture on t h e i r transponder, inquired whether AAl5l had been displayed on t h e Ny CNTR's radar. The NY CNTR repl ied i n the affirmative. TW3l rec i t ed the events surrounding t h e incident and i t s location. The monitor con t ro l l e r ' s response was: "Yes sir, I see w h a t happened here . . . . ' I A t t h i s point , he ins t ructed AAl51 t o
MHz.,TW3l asked AAl5 l to converse on 129.5MHz. A t ranscr ip t ion of t h e change t o Cleveland Center on 133.3MHz. However, before AAl5l l e f t 127.95-
ensuing conversation appears i n Appendix A t o t h i s report .
~ ~ 3 1 contacted NY CNTR again a t 1028:35 and, a f t e r ac t iva t ing the
ATC HANDLIXG OF ~ 5 1
FL350. Four seconds e a r l i e r TW3l had reported l e v e l a t FL350 headed for A t lO23:2O, M 5 l w a s proceeding southwestward on J49 toward PSB a t
PSB. The NY CNTR Sector 29 handoff contro l ler ca l led t h e NY Sector 3
t h e a i r c r a f t was approaching t h e inter- sector boundary. The Sector 3 contro l ler and advised him of AAl5l's locat ion and f l i g h t l eve l , s ince
contro l ler responded that there was another a i r c r a f t a t FL350 25 miles
contro l ler advised that he had no means of resolving t h e impending eas t of PSB (purportedly t h e pos i t ion of TW3l's t a r g e t ) . The Sector 29
t r a f f i c conf l ic t ion because of other t r a f f i c at FL3lO and FL390. The Sector 3 control ler suggested placing AAl51 on a 190" heading ( i n order that t h e f l i g h t might be vectored t o a point about 10 miles or so i n trail behind TW31). He s t a ted fur ther t h a t Cleveland Center would not accept a i r c r a f t a t "the wrong a l t i tude" (33,330 or FL370, u t i l i z e d primari ly by opposite d i rec t ion t r a f f i c ) . This resolut ion of t h e problem was accepted by t h e H29 control ler and an appropriate vector and frequency change was issued t o AAl5l.
believed t o be TW31, AAl5lwas ins t ructed t o proceed d i rec t t o PSB. hrr ing t h e ear ly stages of t h e r i g h t tu rn t o t h i s d i rec t course, t h e two a i r c r a f t nearly collided.
When AAl5l's t a r g e t was a t a su i t ab le distance behind t h a t which was
4/ Sector 29 i s adjacent t o and northeast of Sector 3-PSB.
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ATC HANDLING OF N940BS
to Detroit, Michigan. A t lOl2:25, t h e New York Center Sector 3 radar handoff contro l ler accepted a handoff of N940FS when t h e a i r c r a f t was 9 miles west of Allentown heading d i rec t t o Philipsburg and climbing t o i ts f l i g h t planned cruising l e v e l of 22,000 f e e t (ET.220). A t 1015:25, N940BS contacted the Sector 3 developmental radar contro l ler and reported leaving FLlgO f o r FL220. k i n g t h i s same time period, the Sector 3 controllers were handling another westbound a i r c r a f t headed toward Philipsburg. That a i r c r a f t was W3l.
N940BS was a Gulfstream I1 en route f rom Allentown, Pennsylvania,
Meteorological conditions a r e not considered pert inent t o t h i s incident.
t h i s report were operating without reported d i f f i c u l t y , with one exception. A l l radio a ids t o navigation u t i l i z e d by the a i r c r a f t discussed i n
The Keating, Pennsylvania, VORTAC was scheduled t o be shut darn f o r I maintenance from 1000 t o 1600. Appropriate coordination had been effected ' prior t o the issuance of a Notice t o Airmen concerning t h i s shutdarn. The
information was furnished t o the a s s i s t a n t chief on watch a t the Cleveland Center; however, he f a i l e d t o pass it on t o the sectors concerned with t r a f f i c destined t o u t i l i z e that VORTAC.
The f l i g h t data recorder from AAl5l showed no e r r a c t i c or sudden
parameter t races were recording legibly and t h e f o i l was undamaged. deviations during t h e period of time i n which t h i s incident occurred. A l l
TW3l's f l i g h t data recorder was likewise found t o be operating properly during t h i s time period. The heading t r a c e showed a value of 288 f 1" f o r
was evidenced by a change i n t h e v e r t i c a l accelerat ion (g ) value from a l m i n u t e p r i o r t o the commencement of the evasive maneuver. This maneuver
noma1 l.OOg, i n t h e negative d i rec t ion t o fO.O2g, then pos i t ive ly t o m31 f l .$kg , and subsequently back t o fl.0Og. There was no change i n heading value during t h i s "push-over" maneuver.
was allowed t o continue t o operate subsequent t o the incident fo r the re- mainder of the f l i g h t t o San Francisco, thereby causing a l l recording p r i o r t o 30 minutes before engine shutdown t o be erased.
The cockpit voice recorder (CVR) from TW3l was not examined, s ince it
as a r e s u l t of conversation with TW31, pulled the c i r c u i t breaker on t h e i r The crew of AAl51, a f t e r having been made aware of the near co l l i s ion
CVR i n order t o preserve t h e data recorded thereon f o r l a t e r r e t r i e v a l and examination. The CVR was removed from the a i r c r a f t a t S t . Louis and shipped t o the Board i n Washington, D. C . , f o r examination and tape readout.
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ANAIYSIS
This incident is not t y p i c a l of most i n that t h e causal f ac to r s do not involve t h e in ter re la t ionship of man, machine, and environment. On
was dependent upon t h e a c t s of commission and m i s s i o n by men. t h e contrary, t h e sequence of events which led t o a near co l l i s ion
discussed herein characterized their workload a s moderate. None of them All of t h e contro l lers involved i n the handling of t h e a i r c r a f t
had been on duty fo r longer than $ hours on June 11, 1971, and t h e i r rest periods s ince t h e i r last duty tour had been adequate.
The flightcrew par t ic ipants i n t h i s dynamic s i t u a t i o n had acted on t h e ins t ruct ions or clearances issued by t h e contro l lers , which resu l t ed i n t h e near miss.
cognizant sec tors t h e data concerning t h e impending maintenance shutdown !!?he f a i l u r e of t h e Cleveland Center supervisor t o r e lay t o t h e
of the Keating VORTAC cumpounded t h e control problems. Had t h e contro l ler involved been aware of this shutdown, he could have issued a l t e rna t ive r5Jutings t o a i r c r a f t overflying Keating, or, a t l e a s t , would have been a&re of t h e reason f o r aircraft course deviations and inquir ies i n t h e v i c i n i t y of Keating.
establ ished pos i t ive iden t i ty i n an appropriate manner i n respect t o t h e radar t a r g e t s of TW31 and another westbound a i r c r a f t (N940BS) when they entered t h e east end of his Sector 3 airspace. A t this point t h e air- c r a f t were separated from one another geographically, wi th t h e target of c loser t o PSB. Their appearances on t h e sector frequency were within 40 seconds of one another, wi th both a i r c r a f t climbing, TW3l i n i t i a l l y t o FW30 and N $ O E t o FL220, his f i n a l a l t i t u d e .
There i s no doubt that t h e NY CNTR developmental radar contro l ler
About 2 minutes the rea f t e r , a problem arose a t t h e western end of t h e sec tor with respect t o two other a i r c r a f t . While t h e th ree Sector Controllers focused their a t t en t ion on t h i s near confl ict ion, t h e
versa1 can be a t t r i b u t e d t o t h e fact that N940BS had reached cruising "shrimpboats" r/ on rW31 and N940BS were reversed. The iden t i ty re-
a l t i t u d e while TW3lwas s t i l l climbing, thus creat ing a marked difference
resumed swve i l l ance of that port ion of h i s display t h e r e l a t i v e pos i t ions i n ground speeds which caused N940E t o pass TW31. When t h e contro l ler
of t h e t a r g e t s were reversed.
He now mistakenly considered t h e lead t a r g e t t o be TW3l and t h e following t a r g e t t o be N940BS, about 12 miles i n trail. Consequently, when t h e necessi ty arose t o vector AA151 about 10 miles i n t ra i l behind
I/ A plastic marker used t o indica te t h e locat ion and iden t i ty of a radar target on a horizontal radar display.
~ ~ 3 1 , w h a t actm behind N940Bs a: a l t i t u d e .
Apart fron type of hazardc
might be emPl0: radar t a r g e t
d i f ferent ly , w: t r o l l e r s i n re borne i n mind targets more t garding TW31' Center i n the t o t h e Clevell more, because radar beacon have been d i s would have bf Lorain Subsec crepancy bet1
a more aCCUT: pointed out t
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Federal Avi airspace WE flightcrewr created i n o f , a i r tr;
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~ ~ 3 1 , whet ac tual ly occurred was that AAl5l was vectored about 10 miles behind N940BS and r i g h t across t h e f l i g h t path of TW31 a t the same a l t i tude .
type of hazardous s i tua t ion , that is, by the constant re tent ion of radar ta rget iden t i ty , one i s compelled t o ponder w h a t other means might be employed t o avoid such mistakes i n the fu ture . Phrased differently, what might others have done t o assist the Sector 3 con- t ro l l e r s i n recognizing t h e i r e r ro r? I n t h i s context, it should be borne i n mind that once t h e i d e n t i t i e s had been reversed, with t h e targets more than 10 miles apar t on an east-west l i n e , t h e data re- garding TW3l's purported locat ion which was provided t o t h e Cleveland Center i n the course of the handoff could not possibly have corresponded
more, because of t h e Cleveland Center's s t r a t i f i c a t i o n . a n d concomitant t o the Cleveland con t ro l l e r ' s observed posi t ion of the t a r g e t . Further-
radar beacon code assignments only t h e t a rge t s of TW31 and AAl5l would have been displayed on t h e CLE Lorain Subsector. The t a rge t of N94OW would have been v i s i b l e only t o the Clarion Subsector contro l ler . The Lorain Subsector handoff contro l ler should have recognized the d i s - crepancy between t h e s t a t e d and observed posi t ions of t h e t a rge t being pointed out a s TW31, and should have refused t o accept the handoff u n t i l a more accurate assessment of TW31's posi t ion was accomplished. This action, i f taken, would have prevented the near miss. The ultimate responsibi l i ty f o r maintaining appropriate radar t a rge t iden t i ty i n t h i s instance, however, reposed with the monitor contro l ler a t t h e NY CNTR.
Apart from the obvious means of preventing a recurrence of this
The Board has not emphasized i n t h i s report the applicat ion of the principle of "see-and-avoid," since t h i s incident occurred a t FL350, within pos i t ive control airspace. I n t h i s environment, a p i l o t cannot, because of operational and physiological l imi ta t ions , depend on v i sua l detection of other a i r c r a f t , a l b e i t t h i s case does i l l u s t r a t e that visual a ler tness helped t o avoid an accident. The ra t ionale used by the
airspace was based on the f a c t that because of these l imi ta t ions t o Federal Aviation Administration fo r the establishment of pos i t ive control
flightcrews' capab i l i t i e s t o "see-and-avoid,'' an environment must be created i n which a l l f l i g h t operations a r e known t o , and under the control of, a i r t r a f f i c control .
Probable Cause
The National Transportation Safety Board determines that t h e probable cause of t h i s incident was t h e misidentif icat ion by a New York Center control ler of t h e radar t a r g e t of TW Fl ight 31, which resu l t ed i n inappro- p r i a t e control ac t ion i n respect t o AA Fl ight 151 and which placed t h e two f l i g h t s on a co l l i s ion course a t t h e sane a l t i t u d e .
-a- Recommendation
The Safety Board recommends that:
The Federal Aviation Administration take appropriate action to assure that all air traffic control personnel are made aware
may result and serve to preclude the recurrence of similar of this misidentification incident so that increased vigilance
incidents.
BY THE NATIONAI. TRANSPORTATION SAFETY BOARD:
/ s f JOHN H. REED C h a i r m a n
/ s f OSCAR M. LAUREL Member
/ s f FRANCIS H. McADAMS Member
/ s f LOUIS M. THAYER Member
/ s f ISABKL A. BURGESS Member
D e c e m b e r 29, 1971 AA 1 5 1
Tw3
-9- Attachment
!IEANSCRIPI?ON OF CVR RECORD OF VOICE coramcAmo>l BETJEEN A TRANS WORLD AIRLINES BOEING 707 (FLIGHT TG131) AND AN AMERICAN AIRLINES BOFING 707 (FLIGIIT Ah 151) OM ARIITC CHANXEL 129.5 MHz. , FOLLOm,?G A NEAR MISS ON
JITNE 11, 1971, NEAR PHILIPSBURG, PENNS?3VN11AJ (OAK 71-1-0352)
mm
Airlines Flight 151 Radio transmission made by the captain of American
Airlines Flight 31 Radio transmission made by the captain of 'Wans World
Not c lear ly understood
COidTDTT
Cleveland Center, American one f ive one
This i s TW thirty-one, are you on the frequency?
Roger, TWA thirty-one, American one fifty-one
Ok, did you, ah, d i d you see us, ah, by Philipsburg there?
Negative, we didn't see you a t a l l
Oh man : Ah, we b d t o take evasive action t o avoid collid- ing with you---were---I guess you went r i g h t Over Philipsburg didn ' t you.
No we didn't. We went t o the south of it
Yeah that's ah, you were at t h i r t y five. You see us out t o ah, your right. I think we're a t three o'clock t o you
Okay, we have you over a t the r igh t
Man, if we didn't see you, ah, we'd both be down there on the, ah, -- ah te r ra in down below. It was ah-- pre t ty hairy
Oh, that's why I couldn't understand the heading that he gave us i n the first place. He turned us t o one nine zero on the heading
Yeah, okay I ' m ah, I am going t o make a f i l e a near miss and you do the same, i f you w i l l . I 've had one midair coll is ion and I don't l i k e t o have another one
Okay, t h i s i s TWA thirty-one?
Affirmative, and it happened at, ah, ah, at, ah, l e t ' s say, ah fourteen, ah, fourteen twenty eight and we were eleven miles east of Philipsburg a t f l igh t level three f ive zero
-10- Trunscription (2)
CONTENT
Correct
Okay, where you guy going?
We're @g t o St. Louis
Where you based?
Chicago
down below and t h i s shouldn't be. We're both transponder Okay, ah, ah, I th ink i t ' s the fau l t of the radar controllers
equipped and, ah, we've had too many midair collisions as it is
Right
And the (animal Hiber) says hello
O b Y
We're based i n LA
0l-Y
Fhd of conversation
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