22 December 1996 - Airborne Express 827

On December 22, 1996, an Airborne Express DC-8-63F, registration N827AX, operating as Flight 827 conducted a test flight after undergoing modifications at Triad International Maintenance Corporation (TIMCO), including a "D" check (major airplane overhaul), modification and standardization of cockpit, avionics and airplane systems, installation of a cargo handling system and engine modifications to achieve Stage III noise level requirements.

A partial functional evaluation flight was conducted on December 21, 1996, but was terminated when the airplane developed a hydraulic system anomaly (low fluid quantity indication). Due to maintenance delays the aircraft departed 4 hours and 20 minutes late, at 17.40h, the following day. The crew were assigned a block altitude of FL130 to FL150 with an IFR clearance back to Greensboro Airport. The planned flight duration was about 2 hours.

The airplane climbed through FL090 at 17.43h and was level at FL141 at 17.45h. At 18.05h, after performing several landing gear, hydraulic and engine system checks, the flight engineer told the other flight crew members that the "next thing is our stall series. The evaluation flight profile form required that the flight crew identify and record the speed at which the stick shaker activated and the speed of the stall indication. The crew slowed the aircraft down one knot at a time. At 18.08:09, the sound of rattling was heard on the CVR and, at 18.08:11, the flight engineer said "that's a stall right there... ain't no [stick] shaker" (at 145 knots). The crew tried to recover from the stall by selecting maximum power. The nose was brought down to gain speed. Not able to recover from the stall, the aircraft struck mountainous terrain in a 52-degree, left wing low and 26-degree, nose-down attitude about 3,400 feet msl.

PROBABLE CAUSE: " The National Transportation Safety Board determines that the probable causes of this accident were the inappropriate control inputs applied by the flying pilot during a stall recovery attempt, the failure of the non-flying pilot-in-command to recognize, address and correct these inappropriate control inputs, and the failure of Airborne Express to establish a formal, functional evaluation flight program that included adequate program guidelines, requirements and pilot training for performance of these flights.
Contributing to the cause of the accident were the inoperative stick shaker stall warning system and Airborne Express DC-8 flight training simulator's inadequate fidelity in reproducing the airplane's stall characteristics."


Transcript of the Cockpit Voice Recorder (CVR)

RDO = Radio transmission from accident aircraft
CAM = Cockpit area microphone voice or sound source
CTR = Radio transmission from Atlanta Center
-1 = Voice identified as co-pilot
-2 = Voice identified as pilot-in-command (PIC)
-3 = Voice identified as flight engineer
-7 = Aircraft mechanical voice
-? = Voice unidentified
* = Unintelligible word
( ) = Questionable insertion
[ ] = Editorial insertion
.... = Pause

time source content
1805:37 CAM-3 next thing is our stall series.
1805:40 CAM-1 ... K.
1805:47 CAM-? ** stall.
1805:49 CAM-2 ** that's uuuuuh.
1805:51 CAM-1 we got two oh. what's our uh ... one eighty-eight or one eighty-four.
1805:56 CAM-2 one eighty-four, and ... we should get uh, stall at uh, one twenty-two. I'm gonna set that in my, interior bug.
1806:07 CAM-1 mine's set *.
1806:08 CAM: [sound similar to stabilizer-in-motion warning horn]
1806:10 CAM-3 shaker one twenty-eight if you just hall out call out your numbers, I'll record 'em.
1806:14 CAM-1 that's shaker and the stall?
1806:15 CAM-3 yeah, shaker and stall both.
1806:17 CAM-1 all right.
1806:18 CAM-2 the only trick to this is just don't unspool.
1806:25 CAM-2 I just swapped the igniters. I'll leave 'em on the for the stall.
1806:34 CAM-3 standby rudder pump back on.
1806:36 CAM-1 OK.
1807:08 CAM: [sound similar to stabilizer-in-motion warning horn]
1807:21 CAM-1 looks like, are you saying you don't want to pull all the way back to it and then spool back or just wait.
1807:23 CAM: [sound similar to stabilizer-in-motion warning horn]
1807:25 CAM-2 aw you can do that, just when you get close to the stall you don't want to be unspooled.
1807:28 CAM-1 unspool and then I'll respool.
1807:29 CAM-2 that's fine.
1807:31 CAM-1 speed it up.
1807:41 CAM: [sound similar to stabilizer-in-motion warning horn]
1807:43 CAM-1 guess I better not trim below * two *.
1807:51 CAM-1 yeah, I'm gonna spool now.
1807:52 CAM-2 all right.
1807:55 CAM: [sound similar to engine increasing in RPM]
1808:06 CAM-1 some buffet.
1808:07 CAM-2 yeah, that's pretty early. *
1808:09 CAM: [sound of rattling]
1808:11 CAM-3 that's a stall right there. * ain't no shaker.
1808:13 CAM: [sound similar to increase in engine RPM]
1808:13 CAM-1 set max power.
1808:14 CAM-2 one thirty-three.
1808:17 CAM-3 * p ower.
1808:19 CAM-1 one forty's about where I'm at.
1808:20 CAM: [sound of irregular popping similar to engine compressor stall starts]
1808:23 CAM-2 that's number two engine.
1808:25 CAM: [sound similar to altitude alert signal]
1808:25 CAM-3 ** pull her back.
1808:26 CAM-2 you got it.
1808:29 CAM: [sound of irregular popping similar to engine compressor stall stops]
1808:30 CAM-2 you can take a little altitude down. take it down.
1808:32 CAM-1 ** control. [spoken with buffeting voice]
1808:36 CAM: [sound similar to engine decreasing in RPM]
1808:38 CAM-2 a little rudder.
1808:39 CAM-1 all right.
1808:40 CAM-2 OK.
1808:42 CAM-2 start bringing the nose back up.
1808:43 CAM-1 got it.
1808:45 RDO-2 center, ABX uh, eight two seven is in a descent.
1808:48 CAM-2 now a little back pressure.
1808:49 CAM-1 got it.
1808:50 CTR ... X eight two seven, change to Indianapolis one two eight point four.
1808:52 CAM-2 easy on the rudder.
1808:53 CAM-1 yaw damper on?
1808:54 CAM-2 yaw damper's on.
1808:56 CAM: [sound of rattling increases]
1808:58 CTR ABX eight twenty seven, Indianapolis one two eight point four.
1809:02 RDO-2 ABX eight two seven, we're going to stay on this frequency a minute, we're descending through eight thousand call you right back.
1809:07 CAM-2 nose down.
1809:08 CAM-2 * power in, your gonna get * ....
1809:10 CAM-? *
1809:10 CTR ABX eight twenty seven, you emergency descent?
1809:12 RDO-2 yes sir.
1809:14 CTR OK uh, can you hold seven thousand?
1809:17 CAM-2 now, need some power in, 'n you can use just your outboards if number two is giving you some problems.
1809:19 CAM: [sound similar to engine increasing in RPM]
1809:22 CAM-1 OK.
1809:24 CAM-2 uh, bring two back.
1809:26 CAM: [sound of click]
1809:27 CAM: [sound similar to engine decreasing in RPM]
1809:28 CAM-2 rudder, rudder.
1809:28 CAM-1 I got it.
1809:29 CAM-2 left rudder.
1809:30 CAM-1 left rudder's buried.
1809:32 CAM-2 OK, easy, don't. OK now, easy bring it back.
1809:35 CAM-7 terrain, terrain, whoop, whoop, pull up.
1809:36 CAM-? (really, really)
1809:38 CAM: [sound of impact]
1809:39 End of recording