15 Jul 2014: AMERICAN EUROCOPTER CORP AS350B3 — AIRBUS HELICOPTERS INC — Grand Praire, TX

No fatalitiesGrand Praire, TX, United States

An American Eurocopter AS350B3 sustained substantial damage to its tail boom during a practice hovering autorotation in Texas.

What happened

On July 15, 2014, an American Eurocopter AS350B3, registration N350GP, was conducting a scheduled recurrent training flight in Grand Prairie, Texas. The flight crew consisted of a foreign-rated pilot and a flight instructor, with an interpreter and an observer seated in the rear of the aircraft.

During the training session, the pilot performed a series of maneuvers, including a hovering autorotation. Following instructions from the instructor that were translated by the interpreter, the pilot executed the maneuver, during which the helicopter experienced a slight right yaw and settled onto the ground. The instructor and observer described the impact as a firm or rough landing rather than a hard impact.

Following the maneuver, the training continued with additional autorotations. However, a post-flight inspection of the N350GP revealed wrinkles in the tail boom. Subsequent examination confirmed that the tail boom had sustained substantial damage.

Findings

An inspection of the aircraft following the flight identified structural damage to the tail boom area.

Probable cause

The accident was caused by the flight instructor's failure to provide adequate supervision during a practice autorotation, with the pilot's hard landing contributing to the event.

Contributing factors

Causes

Instructor/check pilot

Other contributing factors

Pilot