noun
flight record; endurance record (in the air)
Refers to a record for the longest time spent continuously in the air, typically by an aircraft, bird, or flying object.
その飛行機は滞空記録を更新した。
The airplane broke the flight endurance record.
渡り鳥の滞空記録は驚くべきものだ。
The flight endurance records of migratory birds are astonishing.
飛行記録 is a broader term for any flight log or record of a flight, while 滞空記録 specifically refers to a record of time spent aloft (endurance).
Compound of 滞空 (たいくう, 'staying in the air') and 記録 (きろく, 'record').