PPRuNe Forums - View Single Post - Crosswind Takeoff overcontrol?
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Old 20th May 2009, 17:46
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JW411
 
Join Date: Oct 2001
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Cecil R Hooks:

Perhaps I can reassure you that there is a huge difference between roll spoilers and lift spoilers.

Roll spoilers are there to augment the ailerons and have little or no effect on lift. (In fact, some aircraft such as the MU-2 don't even have any ailerons but just have spoilers).

Lift spoilers deploy on landing when the aircraft is firmly on the ground. They get rid of lift very quickly, so making the aircraft "sit down" more quickly and make the stopping process much more efficient.

For lift spoilers to operate they either have to be armed or else physically deployed. Even then the "squat switch" (weight-shift mechanism) would have to also sense that either all mainwheels or the nosewheel and the into-wind mainwheels were firmly on the ground before they deployed.

In summary, it should not be possible for the lift spoilers to be deployed on take-off (unless Spanair do your maintenance) and, if I saw lift spoilers out on take-off, I would be very worried.

However, the roll spoilers shown out on your monsoon video are completely normal and would not worry me at all. I hope that helps.
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