Interim Report FZ981

[Eric Janson]

Here's a link to the report - a very sad read.
[url=http://mak-iac.org/upload/iblock/310/In ... 8en%29.pdf]
http://mak-iac.org/upload/iblock/310/In ... 8en%29.pdf[/url]

Having flown the 737 I can't understand why anyone would give the trim a 12 second nose down input. With flaps out the trim moves at a much higher speed. The elevators are tiny compared to the size of the stabilizer - elevator input will not be able to over-ride the stabilizer.

Russia Today has some very good articles about the "culture" at Airlines in the region. Search for "FlyDubaiGate".

[ScudRunner-d95]

Jesus, 12 seconds, possible trim runaway and the crew didn't pick up on it?

[pdw]

[quote author=Eric Janson link=topic=3250.msg9168#msg9168 date=1465020426]Having flown the 737 I can't understand why anyone would give the trim a 12 second nose down input. With flaps out the trim moves at a much higher speed. The elevators are tiny compared to the size of the stabilizer - elevator input will not be able to over-ride the stabilizer.[/quote]


The trim is probably already involved during very unusal steep ASCENT before the plunge, otherwise winding so long is too impossible to be a simple accident. If this is an accident, what's involved to allow it getting that far forward, to unrecoverable. (Same question for the one in Russia not that long ago, approximately the same circumstance/W&B.)


12 seconds of trimwheeling means the trim was winding forward well before the levelling (too much nose up developing due to full thrust up-turn with a light load), the 1/3 fuel held aft in the tanks during the steep accelerating climb suddenly makes a change to fore after extended nosedown winding then power reduction at level; so if elevators tiny, the overtrim is likley just a smaller mistake in the abrupt handling of a go-around in rough air.