text: why do airplanes have a 10,000 m altitude restriction?   airplanes are not restricted to flying at altitudes greater than 10,000 meters. many high-performance military jets routinely fly at altitudes of 13,000 meters and higher. i've flown on commercial jet aircraft at 10,700 meters.  however, at altitudes greater than about 21,336 meters the air is getting too thin for conventional jet engines to operate.