The Government Accountability Office has found that civilian agencies spent $661 million to use and maintain federally-owned aircraft in the government’s 2015 fiscal year.
GAO said Monday 11 civilian agencies own 924 aircraft as of July 2016 and that figure includes 495 airplanes, 414 helicopters, 14 unmanned aircraft systems and one glider.
The State Department owns the most number of aircraft at 248 units while the National Science Foundation has the least at three, GAO added.
Auditors noted 88 of 924 aircraft were non-operational as of July and can be used for parts, displayed or destroyed.
Civilian agencies spent approximately $652 million on operational aircraft which were flown at an average of 275 flight hours in FY 2015, GAO said.
Agencies usually report costs in categories such as maintenance, overhead, fuel or oil and crew, the report stated.
GAO sought comments on its report from NSF, NASA, Tennessee Valley Authority and the departments of State, Agriculture, Commerce, Energy, Homeland Security, Interior, Justice and Transportation.