When the US bought the Harrier they must obviously have bought the technology (intellectual property), not a bad deal considering they had the steam train, the Jet engine, RADAR and the Hovercraft for nothing.

US designed haha. Great British pilot though. Another British pilot once lost communications and radar durong carrier operations in the middle of the Atlantic, and managed to land his Harrier on top of shipping containers on a cargo ship before running out of fuel. The captain was not happy, but they were compensated for the incident.

The United States Marine Corps (USMC) began crew training for the MV-22B Osprey in 2000 and fielded it in 2007; it supplemented and then replaced their Boeing Vertol CH-46 Sea Knights. The U.S. Air Force (USAF) fielded their version of the tiltrotor, the CV-22B, in 2009. Since entering service with the Marine Corps and Air Force, the Osprey has been deployed in transportation and medevac operations over Iraq, Afghanistan, Libya, and Kuwait. The U.S. Navy plans to use the CMV-22B for carrier onboard delivery duties beginning in 2021

The failure of Operation Eagle Claw, the Iran hostage rescue mission, in 1980 demonstrated to the United States military a need[4][5] for “a new type of aircraft, that could not only take off and land vertically but also could carry combat troops, and do so at speed.”[6] The U.S. Department of Defense began the JVX aircraft program in 1981, under U.S. Army leadership