When Laverne and Shirley sit the unconscious pilot, Captain "Smilin' Ralph" Buzz Anderson (Roy Stuart) in the pilot's chair and put his hands on the control wheel, the airplane is shown to go into a nosedive. The clip of the airplane in a nosedive isn't of an airplane in a real nosedive, but the entire view is tilted, evidenced by the clouds also tilting and staying parallel with the plane. When the clip shows the airplane gaining altitude, the entire view is tilted in the opposite direction (nose-up), including the clouds.
The title is a spoof of the Airport movie series, specifically Airport '75 (whose plot it most resembles) and Airport '77.