Following a recent patch, the AI controlled bombers in Arcade Air Assault have a tendency to slowly descend and crash into the ground. Typically, no more than three bombers from each wave will fly level and proceed towards the target.
Each bomber wave will spawn together in a tight group as it would normally. However, the formation will quickly start to spread out. Between one and three bombers will proceed at the normal speed and altitude. The rest of the bombers spread out, slow down, and gradually loose altitude until they eventually crash.
While this would supposedly make the game mode much easier, the game is still typically lost due to bombing of the base, even though most of the AI bombers don’t make it to the target.