Helicopters - 2024
In 2024, the BEA published four reports concerning helicopters accidents. Two of these are principally based on the pilots’ statements.
One of the four accidents was the mid-air collision, during a passenger commercial air transport flight, between a helicopter (F-HEGT ) and an aeroplane (F-AYVV) on 8 February 2024 at Cozy. During this accident, both aircraft were damaged but no occupant was injured. The safety investigation did not find any contributing factor specific to flying a rotorcraft. For this reason, this accident is not enlarged on further in this review. It is detailed, however, in the 2024 light aeroplanes review as a reminder of the weakness of the “see and avoid” rule alone.
The other three accidents involved light, single-engine helicopters and highlighted a recurring difficulty: controlling the helicopter and its environment. One person was injured, two helicopters were damaged and the third was destroyed.
In accordance with international provisions, in addition to the investigations it must or may conduct into events occurring on French territory, the BEA is involved in foreign investigations, in its capacity as representative of the State of design, manufacture, operator or registry. Due to the export of many French-designed and -built helicopters and helicopter engines, the BEA was notified of 69 foreign safety investigations concerning helicopter occurrences in 2024 (including 16 fatal accidents), and appointed an accredited representative for nearly 50 of them.
Accident to the Schweizer 269C registered F-GEXN on 12/05/2023 at Saint-Julien-de-Concelles.
1. Obstacle and safety margin
The ability of helicopters to manoeuvre, land and take off close to obstacles is a notable operational feature. Regulations do not require a minimum distance from obstacles during ground manoeuvres. This flexibility is not without risk. Pilots may authorise themselves to manoeuvre on sites where there is no safety margin for pilot error or unforeseeable technical or environment-related elements.
During the accident to OO-MOK on 15 July 2023 at Dijon-Darois, the pilot hover taxied to the refuelling area with the intention of landing on the H (Helicopter landing and take-off area marking.) close to the pumps. When the skids touched down, the pilot perceived vibrations which he associated with ground resonance. During the manoeuvre to return to hover flight, the helicopter drifted and the blades struck the canopy of the refuelling station. A photo of the windsock close to the accident site indicated wind of at least 25 kt, and an orange weather warning message concerning the risk of severe storms was in force for Côte-d’Or.
Obstacles are a hazard, and flying close to them requires extreme vigilance. The pilot had control of the helicopter, but did not perceive the small safety margin at the tip of the blades, nor the drift caused by the strong wind.
The accident to F-GEXN on 12 May 2023 at Saint-Julien-de-Concelles concerned a power line being struck during an aerial spraying flight. The pilot, although experienced in low-level flying, waived good practices such as site reconnaissance. The repetitiveness and brevity of each rotation may have allowed a certain routine to set in. In addition, the visual hindrance caused by the pilot having the sun ahead of him very probably increased the difficulty of distinguishing obstacles.
Five people were injured in the occurrences mentioned above.
2. Loss of control
Piloting a helicopter requires well-coordinated movements on the flight controls. Each action on one of the reference axes (yaw, for example) automatically requires a correction to be made on the other two axes (pitch and roll, in this case) as quickly as possible.
F-HDFV was damaged during the accident on 24 April 2024 at Herm. During an examination flight for the PPL (H), the student pilot and the examiner lined up on final for an autorotation exercise with a go-around (without ground contact). The examiner noted a number of training points, including a flare carried out too high. During the second exercise, with the engine in idle with the intention of landing, the student again carried out a flare that was too high, and then made a quick, large input when he raised the collective pitch lever. The instructor took the flight controls and lowered the collective pitch lever, before making another input on it to dampen ground contact despite the reduction in rotor speed. With little lift and a slight tilt, the helicopter collided with the ground, slid and rolled onto its side (desktop investigation).
Reminder of themes in previous years
Lack of knowledge of helicopter characteristics and performance
Control of the helicopter and its environment
Collision with terrain in adverse weather conditions for a visual flight
Conducting a flight under the influence of drugs
Lack of knowledge of helicopter characteristics and performance
Risks associated with flying near obstacles or terrain
Organizational weaknesses
In-flight loss of control
Wake vortex generated by a helicopter
Near-collision with a drone
Medical monitoring of crew
Loss of control