1. Physical or mental weariness resulting from exertion.
2. Something, such as tiring effort or activity, that causes weariness: the fatigue of a long hike.
Physiology.
3. The decreased capacity or complete inability of an organism, an organ, or a part to function normally because of excessive stimulation or prolonged exertion.
4. The weakening or failure of a material, such as metal or wood, resulting from prolonged stress.
5a. Manual or menial labor, such as barracks cleaning, assigned to soldiers.
5b. fatigues Clothing worn by military personnel for labor or for field duty.

hm. . . I guess you could call the pilots fatigued then, however fatigues makes me think of BDUs, while pilots in the military always wear jumpsuits. (just trying to keep factual BS out of your fictional BS)

-Justin Kelly