An Automation Confusion Accident?

Air Safety Week, Jan 24, 2005

Timeline of the Jan. 3, 2004, crash of a Flash Airlines Boeing 737-300

02:41:59 -- Take off initiated with standard call outs.

02:42:02 -- TOGA (take off go around) mode engaged, then disengaged at 02:42:04 (old style 737 Classic computer?)

Aileron movements during T/O roll and lift-off were consistent with crosswind.

02:42:43 -- As the airplane was climbing through 440 feet the captain requested Heading Select. The first officer (F/O) confirmed the command and the flight data recorder (FDR) records that Heading Select mode was engaged.

02:42:48 -- Captain requests "Level Change."

02:42:49 -- The F/O announces, "Level Change, MCP speed, N1 armed, Sir."

02:42:59 -- the F/O announces "one thousand." At the same time, ATC reports the departure time and confirmed left turn clearance. The F/O acknowledges the clearance. This was the last ATC transmission from the flight crew. The aircraft rolled to 20? left bank and began a climbing turn. The turn continued as the magnetic heading approached 140? (at an altitude of 3600 feet), at which point the bank angle decreased to approximately 5? left bank.

02:43:19 -- EgyptAir Flight (MSR 227), a flight from Hurgada inbound to Sharm el-Sheikh, called ATC. Conversations between ATC and MSR 227 continue for approximately 60 seconds.

02:43:37 -- The captain calls for the After Takeoff checklist. There was no audible response from the F/O.

02:43:55 -- the Captain calls "Autopilot." There was no immediate response from the F/O or mode changes recorded on the FDR (likely due to callsign MSR and ATC transmissions)

Timeline: 02:43:58 --Captain states, "Not yet."

ASW comment: i.e., "Don't engage autopilot until I've rolled wings level"?

Timeline: 02:43:59 -- FDR records the autopilot engaged, and that the roll mode transitioned to CWS-R mode. This transition would have resulted in loss of Heading Select Mode.

ASW comment: F/O misunderstands and engages autopilot (A/P) anyway (1 sec later). Major implications ensue ... on a very black night, over the Red Sea.

Timeline: 02:44:00 -- F/O states, "Autopilot in command, sir."

02:44:01 -- Captain states "EDEELO," (an Arabic exclamation expressing a sharp response of some kind).

At the same time, the FDR records momentary movements of aileron surfaces. The right aileron deflects to 7.2 degree TEU for one second.

ASW comment: A result of A/P being engaged while rolling (ailerons and even spoilers deflected) then "kicks" and induces a disconnect due to no synchronization with the aileron servo-actuators. In addition the left outboard (#1) slat was faulty and may have remained extended, inducing a minor rolling moment to the right (not a major malfunction).

Timeline: 02:44:02 -- Cockpit voice recorder (CVR) records the A/P disconnect warning and the FDR recorded the A/P disengaged. The aural warning lasted for 2.136 seconds.

ASW comment: But the pilot (busy exclaiming) evidently fails to register what it was conveying and reflexively cancels the autopilot warbler -- then forgets about it (outta sight or outta hearing = outta mind).

During this time, an increase in pitch and decay in airspeed were observed.

ASW comment: Crew is unaware that neither pilot nor autopilot is now in control... aircraft is flying itself.

Timeline: 02:44:05 -- Captain requests Heading Select mode.

ASW comment: Pilot still assumes that autopilot is engaged and has control.

Timeline: 02:44:07 -- F/O states "heading select" and the FDR records Heading Select mode engaging. This mode transition would have resulted in the reappearance of the flight director roll command bar (for direct pilot guidance). During this sequence, the aircraft's left-bank continued to decrease at a slow rate until the airplane was briefly wings level. Beginning at this time, the FDR records a series of aileron motions that command a right bank and subsequent right turn.

ASW comment: Less than a minute to impact. F/O positive response tends to confirm A/P is doing its duty (even though F/O has only hit the Heading Select button).

Pilot thinks that his yoke input is using CWS-R and that the aircraft will roll out on its selected HDG.

Pilot is making necessary CWS roll initiation inputs to the yoke.

Timeline: 02:44:18 -- Captain says, "See what the aircraft did?"

At this point the aircraft bank angle was about 12 degrees to the right. (extended #1 slat may have been inducing a right roll).

ASW comment: Aircraft has gone through the ordained heading without rolling out. Captain is now confused, still convinced that autopilot is still engaged and that he's using CWS-R -- (or rather, thinks that he is).

Timeline: 02:44:27 -- F/O states, "Turning right, sir." Three seconds later, the captain responds, "What?" At the same time, bank angle is 17 degrees to the right and the FDR records the aileron motions to increase the right bank.

ASW comment: Confusion by pilot between displayed bank directions (left for right) and rolls further right? Are the command bars obscuring his interpretations of aircraft roll attitude or is he more likely confusing Western and Soviet-style artificial horizon (AH) displays?