The US Air Force had to scrap one of its brand-new Lockheed Martin AC-130J Ghostrider gunships following a training mishap earlier this year, the service has revealed.

In an Accident Investigation Board report released earlier this month, the Air Force Materiel Command says the adapted Hercules received damage estimated at more than $115 million after a flight-test crew lost control.

Conducted by 413th Flight Test Squadron personnel from Eglin AFB in Florida over the Gulf of Mexico on 21 April, the sortie involved what the USAF describes as an assessment of the AC-130J’s “medium-risk flying qualities”.

While being operated at roughly 15,000ft, “the aircraft exceeded the targeted angle of sideslip until it departed controlled flight,” the report states. It “momentarily inverted, before being recovered after losing approximately 5,000ft of altitude.” The aircraft’s crew – who escaped injury – returned to base and landed safely, but the Ghostrider was rendered a total loss, having exceeded its operating g limits and design load.

AC-130J Ghostrider - US Air Force

US Air Force

Investigators have attributed the incident to the pilot’s “excessive rudder input during the test point, followed by inadequate rudder input to initiate a timely recovery from high angle of sideslip due to over-controlled/under-controlled aircraft,” along with the “wrong choice of action during an operation.”

Contributing factors included: instrumentation and warning system issues; spatial disorientation; confusion; and inadequate provision of procedural guidance or publications to the team; the report states.

The US Air Force Special Operations Command received its first AC-130J at Hurlburt Field AFB in Florida in July 2015, to support testing. Once in frontline use, the type will be equipped with weapons including a 30mm cannon, 105mm cannon and a variety of precision-guided air-to-surface munitions. The service plans to have an operational fleet of 32 of the type by fiscal year 2021, with initial capability slated for FY2017.