ST PAUL, Minn. — The Minnesota National Guard released a summary of the factors that contributed to a helicopter crash on Dec. 5, 2019 that killed three National Guard members.
According to the accident report summary, the crew -- a maintenance pilot, a pilot, and an aircraft mechanic -- were conducting a maintenance test flight to verify the proper installation of the aircraft's hydromechanical unit (HMU).
During the test, the Number 1 engine failed a maximum power check and the Number 2 engine was in the idle setting, causing a dual engine out condition, which the crew was unable to fix, according to the report.
During the investigation, officials say the following factors contributed to the crash:
- The Number 1 engine failed due to an incorrect installation of the Hydromechanical Unit (HMU)
- The inspection of the HMU installation was not completed in accordance with the published installation procedure
- The Maintenance Test Pilot failed to respond to a critical situation during a maintenance maneuver
- The pilot on the controls failed to execute an autorotative descent and landing
- Leaders did not adequately assess the technical inspector’s ability to perform his duties while pending administrative actions
- In accordance with Army Regulation and the Minnesota Army Aviation Standard Operating Procedures, the aircraft mechanic should not have been on the flight because he did not have a valid purpose for being on the flight
“It is critical for us to determine what caused this tragic loss of life – not so that we can place blame, but so that we can do everything possible to ensure nothing like this ever happens again,” said Brig. Gen. Sandy Best, Interim Adjutant General, Minnesota National Guard in the report.
As a result, officials are recommending the National Guard consider administrative action for the mechanic who installed the HMU, the inspector who inspected the maintenance work and provide additional training for maintenance test pilots and all Minnesota National Guard pilots in responding to emergency procedures. The report says, as of January 2020, the inspector is no longer employed with the Minnesota National Guard.
“We continue to grieve with the families of these fallen Soldiers and the Aviation community, and the extended Guard family during this extremely difficult time,” said Brig. General Best. “We hope the conclusion of this investigation and its findings will help to bring them closure and peace.”
