 Exercise Pitch Black 12 was conducted from 27 July through 17 August 2012, and involved 2,200 personnel and up to 94 aircraft from Australia, Indonesia, Singapore, Thailand, New Zealand and the United States.The Ukrainian Air Force inherited about 66-70 Su-27 aircraft after the collapse of the Soviet Union.Lack of funds in addition to the Su-27's high maintenance led to a shortage of spare parts and inadequate servicing.