Other mistake: General Ivan Radek (played by Jürgen Prochnow) is listed as General Alexander Radek in the closing credits.
Other mistake: After the president retakes the plane, the VP sees a red blip on the tracking map and is told it represents MIGs. Then she tells the president they are tracking 6 MIGs. However, the map just showed a single unlabeled red circle to represent the bad guys, and at no point did someone tell her there were exactly 6 MIGs (or, if she knew a squadron was 6, that it was just 1 squadron), which is what it turned out to be. It's not until later that the map has individual icons for each plane involved. (01:43:33)
Other mistake: When Gibbs goes into the Secret Service Room, he passes by an agent who he asks if he is sleeping on the job. He kills the other 3 agents, opens the weapons hold and walks past where the other agent was sitting, and he's now gone, and is still gone when the terrorists storm the cabin. Where did he go? Considering earlier during the tour, Melanie Mitchell warns them not to pass that point without an escort, or they'll be sorry.