Originally Posted by
captjns
On the new generation aircraft, speeds are automatically calculated based on data input in the FMC... again, wrong speeds will be reflected if incorrect weights be input. It's happened before, and will happen again.
However, it was not the incorrect set speeds that caused the crash in KBUF... nor the reliability of the aircraft.
Well.... here's what I'm talking about. I'm not a pilot so maybe someone can comment. According to the CVR transcript , the pilots had the Vref (landing speed) bugged at 118kts:
22:05:29.5 HOT-1
... uh we got the weather. bugs are set eighteen
fourteen flaps fifteen. uh off of twenty three I forget let me look it up.
But, the stick shaker was set to activate at 134 knots, due to the fact that the INCR REF switch was turned on, which increases the point by 20Kts.
So, their speed dropped to 130 knots, well above their bugged Vref. Stick shaker activated, pilot apparently panicked, and there you have it.
Soooo, if there was a warning of some kind that he was setting the Vref below the shaker activation point, might that not have saved the day? I think this is what Colgan is talking about.