Answer:
a short-run decision because the number of aircraft is held constant while the labor input is changed.
Step-by-step explanation:
In the short run, at least one variable or factor of production is fixed and cannot be changed. In the long run, all factors of production can be changed.
In this case, the number of aircraft is the fixed factor of production (capital) while labor is variable because more pilots can be hired. Regulation state that pilots must rest a certain amount of time in between flights, so if you want to increase the amount of flights you need to hire more pilots and cabin crews since regulations do not require planes to rest.