(Intelligent) Premature Speculation On Colgan 3407 Crash
Online speculation swarming around the Feb. 12 crash of Continental Connection (Colgan Air) Flight 3407 in Buffalo that killed all 49 aboard plus one on the ground has moved well beyond probable causes and now includes full-blown speculation on the deceased crew's thought processes. Armchair pundits and pilots have added the NTSB's reports (that the aircraft's stick pusher engaged) to media reports (that its action was followed by a 2-G pilot-commanded pull) to pilots' insights relevant to the captain's experience. What insights? Captain Renslow's time was earned mostly in the smaller Saab 340. He had only 110 hours in the Dash 8. The Saab 340 is more susceptible than the Dash 8 to an icing-induced tailplane stall. An experienced Saab pilot flying an icy approach, theorists speculate, would have been wary of a tailplane stall. Tailplane stalls involve yoke buffeting (stick shaker) followed by a sudden uncommanded movement of the yoke forward (stick pusher) and for many models are instigated by flap extension. A pilot convinced he was experiencing a tailplane stall would initiate proper recovery by pulling the yoke full aft. Of course, that doesn't seem to be what the NTSB is currently considering.
Some pilots (and it appears members of the NTSB) think the evidence so far collected supports the theory that the pilots simply overreacted when the autopilot disengaged on a slow approach and the stick would dropped the nose at a higher than normal speed. That would be how the stick pusher should behave when the icing system is activated. But the NTSB has not yet announced its determination that the stick pusher activated properly and has not yet considered all the evidence relevant to the crash.
Meanwhile, other armchair investigators have latched on to accurate reports that Southwest Airlines has disseminated an alert to its pilots regarding the possibility for ILS interference at Buffalo (due to a ground obstruction). The alert warns that pilots flying the approach on autopilot may experience a sudden pitch up while flying slow on their approach. The NTSB has stated it's aware of the alert and has declined further comment. The FAA, however, through spokeswoman Laura Brown, told AVweb: "This notice has been on charts since 2001 and is on the NORTH side of the airport for the approach to take a right turn on 23, not the SOUTH approach the accident aircraft used for a planned LEFT turn onto 23." Brown said the ILS gear has been flight checked and works fine. We expect the theories will keep coming and will let you know the NTSB's, when it becomes official.