|Quoting Pilotpip (Reply 4):|
The spoilers would be up a bit if the pilot were adding proper crosswind correction.
|Quoting AT (Thread starter):|
Why is this? Isn't the sole purpose of the spoilers to kill lift upon landing? If so, that seems counter productive.
|Quoting 474218 (Reply 6):|
On most large transport aircraft additional roll control is required when the flaps are extended.
|Quoting PhilSquares (Reply 5):
From the 744 FCTM Limit control wheel input to
that required to keep the wings level. Use of excessive control wheel may
cause spoilers to rise which has the effect of reducing tail clearance. All of
these factors provide maximum energy to accelerate through gusts while
maintaining tail clearance margins at liftoff.
A properly executed x-wind takeoff should be accomplished without spoiler activation. Generally, there is enough lateral control using just ailerons alone. On the 744, at low speeds or with the flaps out of the up position, both inboard and outboard ailerons will be available.
|Quoting 767driver (Reply 9):|
The 767/757 FCTM says the exact same thing, however "excessive control wheel deflection" is not defined.
|Quoting 474218 (Reply 13):|
What make the spoilers extend during a strong cross wind and do they extend asymmetrically?
|Quoting 767driver (Reply 14):|
They extend as a function of aileron displacement. As you turn the yoke, the ailerons move along with proportional extension of the spoilers. Example, you turn the yoke to the right, the right ailerons will first move up, then the more you turn the yoke, the spoilers on the right wing will begin to extend to aide in turning the airplane (creating more drag on the right wing)
|Quoting 474218 (Reply 15):|
Also the up aileron/spoiler takes away lift and the down aileron creates more lift, both effect the drag. It is the differential lift that aids in turning, not drag.
|Quoting Vc10 (Reply 16):|
I always thought there was a thing called differential aileron where the up going aileron moved more than the down going aileron, so there was less drag on the down going aileron side [ sorry about all the downing and uping]