The Federal Aviation Administration announced Tuesday that it has suspended the license of a small West Texas charter plane operator after an inspection earlier this year found that an engine on the company’s plane had gone 22 years without required maintenance.

The company, Western Air Express, operates a lone twin-engine Beechcraft Queen Air out of its base in Midland. The aircraft is registered to James Nyerges, according to the FAA.

An April investigation by the FAA found that the left engine on that aircraft hadn’t been overhauled since 1982. FAA regulations require that type of engine to be overhauled after 1,400 flight hours or every 12 years, meaning Western Air Express’s engine should have been serviced in 1994 and again in 2006.

The right engine on that aircraft is also 10 years overdue for the required maintenance and the propellers should have been overhauled in 2015 but were not, the FAA said.

The carrier’s continued operation without the required maintenance “poses an unacceptable risk to aviation safety,” the FAA said.

The findings led the FAA to issue an emergency order Tuesday suspending Western Air Express’s air carrier certificate. The carrier must surrender the license and cannot get it back until the required maintenance is performed, although it does have the option to appeal the ruling.

Western Air Express’ air certificate was previously suspended by the FAA in 2009 for similar maintenance issues.