flight duration; time in the air
Used in aviation, sports (e.g., ski jumping, basketball), and physics to refer to the length of time something remains airborne.
This drone's flight duration is about 30 minutes.
In ski jumping, time in the air also affects the score.
飛行時間 is more general for 'flight time' of an aircraft from departure to arrival, while 滞空時間 emphasizes the duration of staying aloft, often in a single continuous airborne phase.
Compound of 滞空 (たいくう, 'staying in the air') and 時間 (じかん, 'time').