The Me-163 had a huge problem in that the engine could propel it to beyond what the airframe could handle, even in level flight. Trying to zoom up behind enemy aircraft, like the two P-47's that were the first ever combat target of the rocket fighter, was difficult to impossible because the airplane hit compressibility, which it was not designed to handle - and nothing else was, either. The P-47's never even knew they were under attack and the Komet ran out of propellant. So they adopted the tactic of zooming up above the targets, turning off the engine, and diving on them, then zooming up above again.