Airbus AS350 B3e enters vortex ring state during approach in French Alps

Casualties unknown • Borce, vallée d’Aspe, locality of “Belonce”, FR

An Airbus AS350 B3e helicopter experienced a vortex ring state during a landing approach in the Aspe valley, resulting in a hard landing and significant structural damage.

What happened

On 30 May 2022, an Airbus AS350 B3e, registration F-HMFA, was performing a non-commercial cross-country flight in the Aspe valley near Borce, France. The flight, operated by Héli Béarn, was returning to a landing site following a mission to a construction site. The crew consisted of the pilot, a second pilot, and a flight assistant.

During the final approach, the helicopter was flying at a low horizontal speed with a light tailwind. Approximately 30 meters above the ground, the pilot maneuvered the aircraft to slow down by pulling the nose up and then easing the cyclic forward. During this maneuver, the aircraft entered a vulnerable vortex ring state (VRS). The pilot, observing a group of approximately 10 people directly in front of the aircraft, chose not to apply the necessary cyclic input to escape the state due to the proximity of the bystanders. Consequently, the helicopter experienced a rapid increase in descent rate, which escalated from 1,000 fpm to 1,600 fpm in just 11 seconds. To avoid a nearby mountain slope, the pilot executed a 90-degree left turn just before impact. The resulting hard landing caused substantial damage to the tail boom and the rear body structure, though the occupants escaped without injury.

The investigation

The BEA examined data from the aircraft's Engine Data Recorder (EDR) and the Appareo Vision 1000 recorder. The investigation included a visual inspection of the wreckage and an analysis of meteorological conditions, which noted a light breeze blowing up the valley. Technical examinations of the engine and flight control linkages confirmed that all components were operational and no mechanical failure contributed to the accident. The investigation also reviewed video footage captured by witnesses on the ground and analyzed the theoretical VRS envelope using Froude’s theory based on the aircraft's weight and environmental conditions at the time of the accident.

Probable cause

The helicopter entered a vortex ring state due to a high rate of descent during an approach conducted with a tailwind. This situation was compounded by the pilot's decision to avoid aggressive cyclic inputs to prevent endangering people on the ground, as well as potential delays in reaction time caused by the stress of the sudden descent.

Frequently asked questions

What happened in the 2022-05-30 Airbus AS350 - B3E accident near Borce, vallée d’Aspe, locality of “Belonce”, FR?

An Airbus AS350 B3e helicopter experienced a vortex ring state during a landing approach in the Aspe valley, resulting in a hard landing and significant structural damage.

What aircraft was involved and where did it happen?

The accident on 2022-05-30 involved a Airbus AS350 - B3E, registration F-HMFA, at Borce, vallée d’Aspe, locality of “Belonce”, FR.

What was the probable cause of the accident?

The helicopter entered a vortex ring state due to a high rate of descent during an approach conducted with a tailwind. This situation was compounded by the pilot's decision to avoid aggressive cyclic inputs to prevent endangering people on the ground, as well as potential delays in reaction time caused by the stress…

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