noun
Specifically refers to a member of an aircraft's crew, such as a pilot, co-pilot, or flight attendant. Not used for ship or train crews.
その飛行機の搭乗員は全員無事だった。
All crew members of that airplane were safe.
乗組員 is a general term for crew members of ships, trains, or other vehicles, while 搭乗員 is specifically for aircraft.
Compound of 搭乗 (とうじょう, 'boarding an aircraft') and 員 (いん, 'member').