Apparently F-35 pilots had no idea that gusty tailwinds could cause an engine fire on the F-35. But that is exactly what happened last year at Mountain Home AFB in Idaho according to a recently released report from the Air Force Air Education and Training Command.

The Accident Investigation Board report, released Wednesday by Air Education and Training Command, concluded the Sept. 23, 2016, mishap was caused when a tailwind “forced hot air into the inlet of the Integrated Power Pack,” an internal system where the conventional auxiliary power unit and an emergency power unit combine.

The forced air “led to a series of events resulting in insufficient torque applied to the [mishap aircraft] engine during start, and thus the engine rotation speed slowed,” the report said.