Specialist's Factual Report of Investigation Cockpit Voice Recorder

Transcription

1 nondsclosure

2 NATIONAL TRANSPORTATION SAFETY BOARD Vehcle Recorders Dvson Washngton, D.C Aprl 30, 2002 Specalst's Factual Report of Investgaton Cockpt Voce Recorder NTSB Number: DCA0MA064 A. EVENT Locaton: Arlngton, Vrgna Date: September, 200 Arcraft: B , N644AA Operator: Amercan Arlnes B. GROUP N/A C. DETAILS OF INVESTIGATION In support of the Federal Bureau of Investgaton's (FBI's) nvestgaton nto the terrorst act of Amercan Arlnes Flght 77, whch crashed nto the Pentagon n Arlngton, Vrgna, on September, 200, the NTSB Vehcle Recorders Dvson receved an L-3 Communcatons, Farchld Avaton Recorders model A- 00A cockpt voce recorder (CVR) on September 4, 200: The CVR was examned upon recept. The recorder dsplayed evdence of extensve mpact, fre, and smoke damage. The outsde cover had to be cut off of the unt to obtan access to the nsde crash case and tape storage reel, (see pcture #) The crash case was extensvely dented and damaged from the

3 mpact. All fve of the crash enclosure retanng bolts were broken flush wth the top porton of the enclosure. The bottom porton of the crash case was found no longer attached to the upper porton of the enclosure. Fre and hgh temperatures extensvely damaged the nteror tape reel, fre protecton and recordng tape, (see pctures #2, #3). The majorty of the recordng tape was fused nto a sold block of charred plastc. There were several loose peces of charred recordng tape found lyng nsde of the tape enclosure (see pcture #4). No undamaged or usable segments of recordng tape were found n the CVR recorder. Pcture # (exteror and upper crash case) jm m,'.' * '- :;us**% ' --;Q"-f- m

4 Pcture #2 (upper crash case, wth tape and reel assembly) Pcture #3 (tape and reel assembly) PIP^fffP'Yf::^^ W=^"^:fS,IU 2, «*>v* *

5 Pcture #4 (tape fragment, burned) Pcture #5 llustrates what an undamaged dentcal model_farchld A-00A CVR tape and reel assembly would look lke. Pcture #5 (dentcal undamaged Farchld A-00A CVR tape transport) James R. Cash Electroncs Engneer

6 Unted Arlnes Flght 93 - Flght Profle OFFICIAL USE ONLY The followng profle of Unted Arlnes Flght 93 s based on data from the flght data recorder (FDR) recovered from the crash ste, as well as radar data obtaned from the Federal Avaton Admnstraton's Ar Route Traffc Control Centers and the U.S. Ar Force 84th Radar Evaluaton Squadron. Fgure shows the flght path of the arcraft from take off at Newark, NJ to the crash ste near Johnstown, PA. Fgure 2 shows the arcraft's alttude profle for the hour and 2 mnute duraton of the flght. Unted flght 93 departed Newark, NJ at 8:42 am (pont A n Fgures and 2) and reached ts assgned crusng alttude of 35,000 feet at about 9:02 am (B). The flght appears normal untl a bref descent of about 600 feet startng at 9:28 (C). The words "get out of here" and sounds of a struggle were recorded on the ar traffc control rado at FAA's Cleveland Center faclty at ths tme. The Cockpt Voce Recorder (CVR) onboard the arplane began provdng sounds from the cockpt at approxmately 9:32. At 9:34 (D) the arplane starts to clmb from 35,000 feet, and shortly thereafter begns a left turn to the southeast. The arplane mantaned a maxmum alttude of 4,000 feet for about 2 mnutes and then started descendng at about 9:39 (E). Radar statons stopped recevng transponder returns fromual93 at approxmately 9:4. There was a bref nterrupton n the descent at 9:46 (F) as the arplane clmbed from 9,000 feet to 20,500 feet before resumng ts descent. At about 9:57 the arplane started a left turn to the east. Just before 9:59 (G) the arplane was at 5,000 feet when about 2 mnutes of rapd, full left and rght control wheel nputs resulted n multple 30 degree rolls to the left and rght. From approxmately 0:00 to 0:02 (H) there were four dstnct control column nputs that caused the arplane to ptch nose-up (clmb) and nose-down (dve) aggressvely. Durng ths tme the arplane clmbed to about 0,000 feet whle turnng to the rght. The arplane then ptched nose-down and rolled to the rght n response to flght control nputs, and mpacted the ground at about 490 knots (563 mph) n a 40 degree nose-down, nverted atttude. The tme of mpact was 0:03:.

7 Fgure. UA-93 Radar Ground Track A - UAL 93 takes off from Newark, NJ at 0842 EOT. B - UAL 93 levels off at assgned alttude of 35,000 ft. C foot devaton from assgned alttude. D - Starts clmb to 4,000 feet, then turns towards Southeast. E - At max alttude of 4,000 feet; xponder returns cease 2 mn. later. F - Bref nterrupton n descent. G - Evdence of struggle on CVR; arcraft starts clmbng. H - Arcraft noses down and starts rapd descent. I - Arcraft arcraft mpacts the ground nverted and at hgh speed. Q _ 00:03: AM I

8 ^_, 0),8 (D TJ 3 ^ouuu Af\(\nn HUVJUU ocnnn oouuu onnnn ouuuu zouuu ocnnn onnnn u-» < ^nnn I OUUU nnnn I UUUU *500n n\j _ _....]: "" '. : -- ".'.. - '.:...I" ::!:: ,-!.... ' f - fj Fgure 2. UA-93 Alttude Profle _.. _... \f t I J / : j... " ' _ '...'. ( *._... c_. so D r -... D f~~ C ) ( ) 44 k «: *: -8-! \ - V :± B - UAL 93 levels off at assgned alttude of 35,000 ft. C foot devaton from assgned alttude. D - Starts clmb to 4,000 feet, then turns towards Southeast. E - At max alttude of 4,000 feet; xponder returns cease 2 mn. later. F - Bref nterrupton n descent. G - Evdence of struggle on CVR; arcraft starts clmbng. H -Arcraft noses down and starts rapd descent. I - Arcraft arcraft m pacts the ground nverted and at hgh speed.... F \!... V \ -UAL 93 takes off from Newark, \-... V30:00 08:40:00 08:50:00 09:00:00 09:0:00 V \00 09:30:00 09:40:00 09:50:00 0:00:00 0:0' -..: \~ <z... {: 4- CO A -fj ' '- H. " ' " " " Eastern Daylght Tme, h,..a/im:ss (= UTC -4 Hours) /... ^..... H."If t.