Investigators with the US Marine Corps (USMC) have concluded that pilot error, rather than a material or mechanical failure, caused the fatal crash of a Bell-Boeing MV-22 tiltrotor in 2023 in Australia.
The incident occurred on Melville Island near the northern city of Darwin, where the Pentagon maintains a rotational force of US Marines. The August 2023 crash killed three USMC personnel and injured five more.
An inquiry completed by the 1st Marine Expeditionary Force and released on 9 August found the MV-22 incident pilot lost situational awareness while attempting to land.
“During the flight’s final approach to the pre-coordinated landing zone, the aircraft executed three extreme right banks, causing an aerodynamic stall condition,” the USMC says. “Follow-on flight manoeuvres were unable to recover the aircraft, resulting in the crash.”
Less than six months later, a US Air Force CV-22 crashed off the coast of Japan, killing eight airmen, prompting a worldwide grounding of the USA’s Osprey fleet.
Unlike the Melville Island incident, the crash in Japan was caused by a “catastrophic aircraft mechanical failure”, according to the USAF. In July, the service revealed for the first time the specific nature of that catastrophe: failure of the left-side prop-rotor gearbox combined with the pilot’s decision to continue flight, despite a cockpit warning about metal fragments detected in the gearbox.
The Pentagon says that issue has not previously been observed in earlier Osprey mishaps. Other V-22 crashes have been attributed to a problem known as hard clutch engagement.
While the tiltrotor has since returned to limited flight operations, the Pentagon’s V-22 airworthiness authority in June said flight restrictions on the Osprey would likely remain in place for another year, as the Pentagon attempts to address the issues.
“We are methodically looking at material and non-material changes that we can make to allow for a full mission set without controls in place,” said Vice Admiral Carl Chebi, the top officer at Naval Air Systems Command (NAVAIR), in remarks to US Congress.
According to NAVAIR, the Osprey is currently approved only for flights within a restricted envelope. That includes remaining within 30 minutes flying time of a divert airfield.
The USMC is the largest V-22 operator, with 348 examples in service.
