Either the production shot an empty plate and a clever animator did a brilliant job animating the jet within the frame, or the production photographed an actual fighter jet taking off (then erased the fighter jet and put the stealth fighter in its place), which would give the shot a built-in amount of spontaneity.
For this shot, it turns out that the aerial unit for "Stealth" photographed actual F-18 fighter jets landing and taking off from the aircraft carrier USS Abraham Lincoln, according to Jody Duncan's article in Cinefex 103.
Also, I wanted to include this quote from director Rob Cohen, also from Cinefex 103:
Cohen used the term 'gamer cool' to describe his overall aesthetic for the movie. "Gamer cool meant that a kid who is a computer game fanatic would look at every aspect of this movie and think, 'I don't want to just watch this movie-- I want to play it!"
Dear lord. So, did any of you 'computer game fanatics' out there who saw "Stealth" want to play the movie? (Whatever that means.)