The outside shots show Boeing 747 but the internal shots are obviously a narrow body aircraft, not a 747.
At the end of the episode the Army general is shown wearing a company grade service cap (no scrambled eggs) on the visor. An obvious uniform mistake.
The footage of the 747 landing at the end of this JAG episode is from "Air Force One" so in at least two shots it can be seen that the aircraft Rabb is landing is not "Oceanic" airlines but a 747 painted to appear as Air Force One. The presidential seal is even visible in one scene. The notional "Oceanic" airlines is, itself, from a 70's era disaster movie.
When Harm dodges the missile, the right inboard engine (number three) is hit and catches fire. Harm then pulls the fire switch for the fourth engine. This would have shut down the outboard engine while leaving the inboard on fire. With both right engines out, the 747 would be almost impossible to fly much less land.