The windows are so small because Concorde cruised at 60,000 feet. At that altitude the usual oxygen masks won't keep you conscious. The windows are small so t

The windows are so small because Concorde cruised at 60,000 feet. At that altitude the usual oxygen masks won't keep you conscious. The windows are small so that if one ever failed, Concorde could descend fast enough to an altitude where the masks would work before the pressure dropped too low.