Mishap: The crew was performing a high-angle, side-slip at Eglin AFB, Fla., during handling tests of the developmental gunship when the aircraft departed controlled flight at 15,000 feet over the Gulf of Mexico, according to the AIB. The AC-130J "tumbled inverted" before test pilots were able to recover controlled flight, entering a vertical dive, on April 21. The aircraft lost 5,000 feet altitude, pulled 3.19 Gs, and oversped the flaps' maximum allowed airspeed by 100 knots before returning to level flight. The AIB determined the pilot's excessive rudder input and failure to quickly recover from uncontrolled flight were the primary cause of the mishap. Problems with the aircraft's warning system, pilot disorientation, confusion from being hit with unsecured equipment, and inadequate technical guidance also contributed to the mishap. The aircraft, serial number 09-5710, also suffered a similar incident in February, and has been grounded since the April mishap. Loss of the aircraft is estimated at $115.6 million.
5710 