Part 4 of 5:
Originally Posted by protectthehornet
Anyone who has flown 737's or anything with underwing mounted engines notices the first flight that if you add power the nose goes up...conversely reducing power makes the nose go down. A basic concept of holding pitch would be...throttles forward, yoke forward, throttle back, yoke back.
Essentially, I agree with your premise … but it is wholly dependent on the control authority retained by the elevator surface(s). If that(those) surface(s) does(do) not have sufficient authority, the airplane will not respond as you indicate regardless of what the flight crew does with the controls in the cockpit.
Originally Posted by protectthehornet
The pitch up you mentioned was also caused by the way the leading edge devices were set back in those days...the british had even noticed that in icing conditions with flaps less than 15degrees, the pitch up could be bad.
On January 13, 1982, (yes, this was the same day as the Washington, DC accident) in Scandinavia, another B737 was subjected to a rather fierce snow/freezing rain scenario while taxiing out and awaiting takeoff clearance. As the crew initiated the takeoff and brought the control column “to neutral or slightly aft of neutral to prepare for the rotation” (quote from the Boeing manual), that B737 auto-rotated just like the B737 in Washington. However, because this airplane was subjected to a crosswind, the deformation on the wings was asymmetrical. The airplane pitched up to about the same pitch attitude as in Washington (in the neighborhood of 24 degrees) but because of the asymmetrical deformation, the pitch was asymmetrical as well, and resulted in a pitch up and roll. The crew had the control column against the forward stops. They slammed the throttles to the firewall, went to full opposite aileron, full opposite rudder – all to no avail. Please note … additional thrust was not beneficial. The crew was along for the ride. However, as the roll continued over toward 90-degrees, the nose began to fall. As the nose began to come down toward the horizon (because of the bank - not because of the forward control position), the airplane began to accelerate. As it accelerated, the outboard portion of the affected wing began to produce lift and the aileron became effective. The crew rolled level less than 100 feet above the ground. When advised of the existence of this circumstance, the NTSB chose not to look into it.
Originally Posted by protectthehornet
The first officer/copilot did notice something wrong and called it out...the young pilot, who didn't know jack, could have looked at N1 which should have been in the high 90's%. There seems to have been a lack of checklist discipline, whether by poor design or misunderstanding. Firewalling the engines and pushing forward on the Yoke might have saved them...but they didn't try.
Of course there will always be the “coulda, woulda, shoulda” comments on almost anything … post-incident. The F/O
did express concern over something – but, while the NTSB is convinced it was an “engine anomaly,” I am of the opinion that we don’t know what it was that garnered his interest. I gave my opinion above. But, clearly there was nothing said … and it would make sense that, if there was something that was identifiable, the F/O would have indicated what it was that was bothering him. Therefore, I maintain that is wasn’t an “engine anomaly” that was recognizable by reference to the engine indicating instruments. Additionally, he was vacillating over whatever was bothering him.
Again, from the CVR transcript:
1600:02 CAM2 “That don’t seem right … does it?”
1600:05 CAM2 “Ah, that’s not right.”
1600:07 CAM2 “Well…”
Clearly there is the following sequence: concern – possible resolution of that concern – concern – possible resolution of that concern.
Adding thrust would not have made any difference – and it
did not make any difference to the crew in Scandinavia. Pushing forward on the control column had little, if any effect. If we can believe the CVR transcripts, both pilots were pushing forward on the controls. Again, from the CVR transcript:
1600:31 CAM1 “Vee one”
1600:33 CAM1 “Easy”
1600:37 CAM1 “Vee two”
1600:39 CAM (Sound of stickshaker starts and continues to impact - there is also a noticeable sound of the stall buffet).
1600:45 CAM1 “Forward, forward”
1600:47 CAM? “Easy”
1600:48 CAM1 “We only want five hundred”
1600:50 CAM1 “Come on, forward”
1600:53 CAM1 “Forward”
1600:55 CAM1 “Just barely climb”