Wingtip vortices are strongest during which flight phases due to the angle of attack being highest?

Wingtip vortices are strongest during which flight phases due to the angle of attack being highest?

• A. Cruising flight
• B. Takeoff, climb, and landing
• C. Descent
• D. Hover

Answer: (B)

Wingtip vortices are strongest when the wing is producing the most lift, and lift is closely tied to the lift coefficient, which grows as the angle of attack increases (especially with flaps or other lift devices used during takeoff and landing). So during takeoff, the airplane runs at low speed but high lift coefficient to get airborne; during climb the angle of attack remains relatively high to continue gaining altitude; and during landing the aircraft again uses a high lift coefficient to fly at a low speed. All of that strengthens the wingtip vortices. In cruising flight the aircraft flies fast with a smaller angle of attack, giving a lower lift coefficient and weaker vortices. In descent the lift is reduced as the airplane lowers, so vortices are not as strong. Hover isn’t a typical fixed-wing condition and doesn’t produce the same wingtip vortex pattern, so it isn’t associated with the strongest wingtip vortices.

Wingtip vortices are strongest when the wing is producing the most lift, and lift is closely tied to the lift coefficient, which grows as the angle of attack increases (especially with flaps or other lift devices used during takeoff and landing). So during takeoff, the airplane runs at low speed but high lift coefficient to get airborne; during climb the angle of attack remains relatively high to continue gaining altitude; and during landing the aircraft again uses a high lift coefficient to fly at a low speed. All of that strengthens the wingtip vortices.

In cruising flight the aircraft flies fast with a smaller angle of attack, giving a lower lift coefficient and weaker vortices. In descent the lift is reduced as the airplane lowers, so vortices are not as strong. Hover isn’t a typical fixed-wing condition and doesn’t produce the same wingtip vortex pattern, so it isn’t associated with the strongest wingtip vortices.