What happened
On 11 May 2019, an Airbus EC135-T2 PLUS, registered F-HTIN, was conducting a HEMS (Helicopter Emergency Medical Service) mission near Le Conquet, France. The crew, consisting of a pilot, a technical crew member, a doctor, and a nurse, was approaching Blancs Sablons beach to treat an injured person.
During the final approach, the pilot observed a paraglider flying on a parallel path. To avoid disturbing the paraglider with downwash, the pilot decided not to perform a go-around but instead continued the approach, assigning the crew to monitor the paraglider's position. Simultaneously, the paraglider pilot was slope soaring near the cliffs. As the helicopter and paraglider passed each other, the paraglider's wing suddenly collapsed, causing the pilot to fall to the ground. The one fatality was the paraglider pilot.
The investigation
The BEA conducted a detailed investigation, utilizing flight path data from the helicopter's Hélisafe system and advanced aerodynamic modeling. To reconstruct the event, investigators worked with Airbus Helicopters Deutschland and specialized modeling firms to simulate the helicopter's wake vortex.
By combining flight path recordings, witness statements, and photogrammetric analysis of photos taken on the beach, the BEA was able to estimate the paraglider's trajectory. The investigation also examined the pilot's decision-making process, the adequacy of the site reconnaissance, and the existing knowledge within the aeronautical community regarding helicopter-generated turbulence.
Findings
- The investigation established that the helicopter's wake vortex reached the paraglider's path and was transported toward the cliffs by the prevailing north-westerly wind.
- The airspeeds and direction changes caused by the turbulence exceeded the structural and aerodynamic limits of the paraglider wing, leading to its collapse.
- The helicopter pilot's decision to use a semi-direct, low-altitude approach restricted the available maneuvering space for the paraglider.
- The site reconnaissance was inadequate, as the pilot did not identify the paraglider early enough to allow for sufficient warning or an alternative flight path.
- There is a significant lack of awareness regarding the strength of helicopter wake vortices; pilots often underestimate the turbulence produced by rotorcraft compared to fixed-wing aircraft of similar weight.
Safety action
Following the accident, the operator, Babcock, implemented enhanced safety promotion regarding threat and error management (TEM) and revised its operations manual concerning site reconnaissance and the presence of paragliders.
Additionally, the BEA issued a safety recommendation [FRAN 2021-007] to EASA, requesting that they work with manufacturers to assess and communicate the magnitude of wake vortices generated by helicopters relative to fixed-wing aircraft of equivalent weight to improve awareness in the aviation community.