 Right after the U.S. backed anti-communist forces took over the government, 13 Indonesian MiG-21s were delivered to the U.S. in exchange for T-33, UH-34D, and later, F-5 and OV-10 aircraft.All remaining MiG-21s were grounded and retired due to lack of spare parts and the withdrawal of Soviet maintenance support.The MiGs were added to the 4477th Test and Evaluation Squadron ("Red Eagles"), an USAF aggressor squadron at Tonopah Test Range.