King of the Greenie Board (1) - S5-E1
Continuity mistake: When Harm deals with the Lear Jet, his F-14's registration number keep changing with each different shot of it.
The Bridge at Kang So Ri - S5-E18
Continuity mistake: When Harm is landing the plane, there is a shot of his hand on the controls, but it is minus his school ring which was there in the previous shots.
The Witches of Gulfport - S5-E21
Continuity mistake: While Mac is in a restaurant with three of the Wiccans, another woman comes over to give them verbal abuse. When you first see her, part of her dress is showing. When the camera comes back to her, that part is no longer seen. Also, the exterior scenes indicate that the location really isn't Gulfport.
Chosen answer: When landing on an aircraft carrier, a pilot "calls the ball" by confirming to the landing signal officer (LSO) that they have the carrier, and more specifically its landing guidance systems in sight. Carriers use a Fresnel lens system which is a light only visible at a certain angle, so if a pilot sees the "ball" they are at the correct altitude and glide slope for landing.
Sierra1 ★