Wow, this thread has now developed into a automatics versus handflying discussion. I wonder though if that was really the case. Both pilots occupying the pilot seats were ex AF. I doubt wether they weren’t capable of manual flying. I see a lot of human factors in this accident.
Presumably, the FO was being trained as a new FO on the A/C, he was also (presumably new on the A/C as there was a second FO (in my airline we do that in the first week on line training)
He came in established on the localizer and intercepted the G/S, more than likely the pl went to idle as he was going down and lowering the gear and lowering the flaps, basically slowing down. Shortly thereafter the faulty RA caused the AT to engage retard mode. The exact sequence doesn’t matter. The pl did what one would have expected them to do, the only thing wrong at this point was that the FMA annunciation read RETARD instead of MCP speed. The FO might, I stress might, have seen this but being new to the A/C not have realized even that that was not the correct annunciation. Once again the pl’s did what one would expect at this point. The captain may not have noticed because he was busy lowering the gear and selecting flaps 15(probably watching the speed and altitude and maybe even the GS annunciation, but not the retard annunciation) .
All was normal for the next approx 70 seconds. The A/C did exactly as it was supposed to do,slowing down. They next selected flaps 15 and rotated the MCP speed selector to FAS. This is where the second clue that something was not right should have become apparent, the AT didn’t move forward to maintain FAS. Having spoken to two college’s that tried it in the sim, it took 25 seconds to decelerate from FAS to stickshaker speed. So what occupied the pilots that they didn’t notice the speed dropping below FAS? Well, for one, they were reading the landing C/L. It takes about 4 seconds and boeing says that both pilots have to look at the selections. However it was a training flight, maybe the FO forgot to arm the speed brakes, maybe the captain forgot the select the engine start switches to CONT. In any case, for 25 long seconds they did not notice that the speed went from FAS to stickshaker.( bad airmenship for sure, but still I wonder what kept the occupied).
Finally, the stick shaker went off(somewhere around 800 feet) completely unexpected. The FO, out of primal training pushed the pl’s full forward( and mistakenly didn’t push the AT disconnect button, btw, I think boeing may face a law suit there because the FCOM procedure for a stall recovery does not explicitely says to disconnect the AT, common sense notwithstanding)) and probably pushed forward on the yoke. At this moment the captain took over( I heard this from a reliable source).
So here you are, the captain took over at a critical point, probably using both hands to push the yoke forward, more than likely an autopilot disconnect wail going off, possibly a “glide slope”, “sink rate” or “terrain” warning going off and the captain not noticing that the PL’s were going back to idle.
The rest is history!
So was this an automation v. hand flying deal. Who knows. The FO could have been the best stick around. Maybe it was not his hand flying skills but his understanding of the automatics that did him in. Showing proficiency in automatics is also required in getting a type!! Maybe because he was such a good stick but not knowing the modes of the automatics was the problem.
So, In hindsight, I don’t think there is anything wrong with the airplane design, It did wat it was supposed to. There may not have been anything wrong with the manual flying skills of the flight crew. It may have been a training flight were all the holes in the swiss cheese lined up.
The FMA unnuciation shortly after GS capture, RETARD instead of MCP, I could have missed that, The PL´s not going forward at FAS, I wouldn´t have missed that(hey, I´m a nervous flyer),missing the AT disconnect button in a completely unexpected stall condition at 800 feet, I wonder!!! And then missing the PL going back, fighting a stall with a myriad of warnings going off, I wonder how many guys would have caught that.
If you ask how many guys would shut down the wrong engine? a very unlikely situation, and still that happened in the UK. So I can completely see how a crew could miss disconneting the AT during a high stress event!!
Last edited by flyburg; 21st Mar 2009 at 01:19.