Originally Posted by
aviationluver
Hello from the states. I'm doing some review for an upcoming interview and I was reviewing my FAA ATP material.
There's one question and answer that I don't agree with. I wrote the FAA two weeks ago about this question (because I have no life) and never got a response.
FAA Airman's Information Manual (AIM) 7-3-3 and FAA ATPL question 9119:
"Which flight conditions of a large jet airplane create the most severe flight hazard by generating wingtip vorticies of the greatest strength?
A. Heavy, slow, gear and flaps up.
B. Heavy, slow, gear and flaps down.
C. Heavy, fast, gear and flaps down."
The FAA says the correct answer is A.
However, I disagree. I think the correct answer is C because when a plane has it's flaps down, the plane is generating more lift and drag, thus creating a greater disturbance in the air. Also, with the gear down, there is more turbulence from the disturbed flow off of the gear. Finally, when a plane is traveling fast, the wing is generating much more lift than when the same plane would be flying slower.
Does anyone agree with me? What are your opinions?
Thanks.
You are alarmingly incorrect. Going faster or putting out flaps does not generate more lift - not if the yoke monkey on board is maintaining level flight..... Think about it....
More flaps or higher speed will indeed create more drag, and I suppose 'disturbance through the air'. However this question is limited to one specific aerodynamic phenomenon.
This is all about angle of attack. With flaps out you have larger wing area, therefore you reduce angle of attack to maintain level flight .This creates less pressure under the wing and hence a weaker vortex. Going faster also requires a lesser angle of attack to achieve the same lift, with the same result .