Five operators wouldn't be needed for a bomb. They would be needed for the hijacking, which could be aborted with a bomb detonation. It's quite possible the hijackers were confronted by a planeload of scared and furious passengers who didn't want a repeat of 9/11.
Remember also, that at least one of the set of 9-11 hijackers claimed to have a bomb.
That may be one way the terrorists assure 'destruction'--leader or all 5 have a bomb. If hijacking seems impossible, at least one detonates.