After 35 years in flight, the US military says it's done buying one of its most unique and controversial aircraft

• Since its first flight in 1989, the V-22 Osprey has provided a unique capability to the US military.
• Despite its development over the past three decades, the Osprey still faces mechanical issues.
• The Marines, Air Force, and Navy plan to fly Ospreys for decades, but they don't plan to buy any more.

The US military is the largest aircraft operator in the world, with more than 13,000 manned planes and helicopters of all types in service.