d. Wake turbulence

Bottom line

Wake turbulence consists of wingtip vortices created when an airplane generates lift, as air spills over the wingtips from the high pressure areas below the wings to the low pressure areas above them. An aircraft generates vortices from the moment it rotates on takeoff until touchdown, so pilots should note the rotation or touchdown point of the preceding aircraft. When taking off behind another aircraft, rotate prior to the point at which the preceding aircraft rotated.