HOWELL, Mich. (AP) — Federal investigators have determined that a misplaced air filter screen probably caused a small plane’s engine failure and crash in southeastern Michigan that killed a Delta airlines pilot and an aircraft mechanic two years ago.

The improperly installed metal intake screen allowed the filter element to become displaced and block air into the engine, according to National Transportation Safety Board report.

With air intake blocked, the Aero Commander 200 single-engine plane lost total power and crashed soon after taking off from Livingston County Spencer J. Hardy Airport near Howell about 45 miles (70 kilometers) northwest of Detroit, The Detroit News reported.

Those killed in the August 2019 crash were pilot Phillip Colmer, 64, of Chelsea, and James Tafralian, 68, of Webberville. The NTSB report dated Sept. 16 said they were on a “maintenance check flight” after an overhauled engine and three-bladed propeller had been installed.

Colmer was a Delta airlines pilot with a distinguished naval career and prominent contributor to Project Recover, which sends volunteers to remote regions to retrieve the remains of U.S. airmen lost at war. Tafralian was an aircraft mechanic well known in the skydiving community.