PPRuNe Forums - View Single Post - 737 max crosswind take-off roll. Question on rudder
Old 6th Feb 2012, 06:57
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Tee Emm
 
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Spoiler drag below about 120 knots is, I believe, irrelevant.
An F/O on the 737-400 told me of his experience of being PNF during a take off where the crosswind component was around 15 knots. The captain (from the old school of captains from a particular former Australian legacy airline) pre-set almost half control wheel deflection at the start of the take off roll and held that deflection for the whole take off run.

Within around 10 knots of V1 the acceleration appeared to slow markedly - in fact so much that much more runway was eaten up than a normal take off at the same weight. The F/O was concerned that V1 was now invalid.

Spoiler drag below about 120 knots is, I believe, irrelevant.
This contradicts the FCTM advice that" reverse thrust and speedbrake drag are most effective at high speed" while at the same time the FCTM displays a diagram indicating that landing with speed brakes not extended increases the landing distance by 630-900 ft. As the average touchdown speed on the 737 is in the region of 120 to 145 knots then clearly spoiler drag is significant near typical rotation speeds and unnecessary control wheel deflection throughout the take off roll will extend take off roll.

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