Annual aircrew survey.
D000401:Aircraft / Q000706:statistics & numerical data*; D001359:Aviation / Q000592:standards / Q000706:statistics & numerical data; D003625:Data Collection; D004522:Educational Status; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005069:Evaluation Studies as Topic; D012449:Safety; D012456:Salaries and Fringe Benefits / Q000706:statistics & numerical data; D014481:United States; D000078329:Workforce