Three U.S. service members were also wounded and one U.S. civilian was killed in the ambush by a lone Islamic State member in central Syria.
The U.S. currently has hundreds of troops deployed in eastern Syria as part of a coalition fighting the Islamic State group.
The force has named satellites and ground systems after mythological creatures, ghosts and Norse pantheon, to name a few.
Government auditors said known problems with the Osprey have gone unresolved for years and in some cases at least a decade.
