An Air Force investigation has revealed that a fatal Osprey aircraft crash off Japan last November was caused by cracks in a metal gear and the pilot’s decision to continue flying despite multiple warnings to land. The crash resulted in the deaths of eight Air Force Special Operations Command service members and prompted a military-wide grounding of the fleet for several months. This incident is one of four Osprey crashes in the past two years that have raised concerns about the safety of the aircraft and sparked debates among services about its future role.
The investigation determined that a critical component called a pinion gear in the proprotor gearbox failed, leading to the crash. Although the Air Force is confident that the pinion gear was the source of the problem, the exact reason for its failure remains unknown. The investigation also criticized Pentagon leadership for not sharing crucial safety data that could have informed crews about the seriousness of the risk associated with the proprotor gearbox components.
The pilot, Major Jeff Hoernemann, and his crew encountered vibrations and multiple warnings during the flight, indicating potential issues with the aircraft. Despite receiving six chip burn warnings, which are signs of stress on the gearing system, Hoernemann chose to continue the flight rather than land as a precaution. The investigation revealed that Hoernemann’s focus on completing the military exercise and a lack of direct communication within the crew contributed to the decision not to land earlier.
As the Osprey approached an airfield for an emergency landing, the proprotor gearbox failed, leading to a catastrophic chain of events that resulted in the aircraft crashing into the water and claiming the lives of all on board. Following the crash, new directives have been implemented to ensure crews land promptly upon receiving warnings, and efforts are underway to develop a system that provides real-time vibration data to pilots for enhanced situational awareness during flights.
The victims of the tragic accident were identified as Maj. Eric V. Spendlove, Maj. Luke A. Unrath, Capt. Terrell K. Brayman, Tech. Sgt. Zachary E. Lavoy, Staff Sgt. Jake M. Turnage, Senior Airman Brian K. Johnson, Staff Sgt. Jacob M. Galliher, and pilot Maj. Jeff Hoernemann.
