While Homer is trying to get Bart off the plane, Marge's pearls briefly turn white.
When the car goes under the plane it is under the wing, in the next shot the car is still trying to get under the wing of the plane.
Sideshow Bob could not hide out inside the blimp's helium pocket as there would be no oxygen to breathe.
A U.S. Air Force airman tells a group of people, including Lisa, how easy it is to fly the Harrier Jump Jet at the Air Show in Springfield, indicating that it is so easy to fly that a child could do it. In reality, the Harrier is among the most challenging and least forgiving aircraft to safely operate, especially in its V/STOL mode (vectored flight).
The U.S. Air Force does not operate the Harrier. The only branch of the U.S. military that operates it is the U.S. Marine Corps.
Colonel Hapablab is identified as a Colonel but is clearly seen wearing the one-star insignia of a Brigadier General.
Sideshow Bob is seen returning to prison by the end of the episode, but for stealing a nuclear bomb and threatening to destroy the city, he would have committed an act of terrorism and be put to death.
When Homer mistakes the sign for free Duff as alcohol-free Duff priced at $6, he clearly drinks six cups, but the till registers the transaction as $48 instead of $36.
At one point it is mentioned that there is "not a cloud in the sky", yet you can clearly see clouds throughout.