EC155 / Light Aircraft Mid Air Collision: All Survive (Airbus EC155B1 F-HEGT of Héli Sécurité and Nord 1203 III F-AYVV)
On 8 February 2024 Airbus EC155B1 F-HEGT of Héli Sécurité and vintage single engine piston Nord 1203 III F-AYVV collided in mid air over Montmélian, Savoie. Both aircraft were damaged, but remained controllable. Their pilots managed to land, in a field for the helicopter and at Albertville aerodrome for the aeroplane.
Damage After Mid Air Collision of Airbus EC155B1 F-HEGT of Héli Sécurité and Nord 1203 III F-AYVV (Credit: BEA)
Le Bureau d’enquêtes et d’analyses pour la sécurité de l’aviation civile (BEA) issued their safety investigation report in December 2024.
The Accident Flights
The dark blue helicopter, flown by a single pilot (3000 hours total time) accompanied by a ‘safety pilot’ (400 hours), was transporting six passengers from Chambéry airport to the Courchevel mountain airfield.
The aeroplane (white with red wing tips and propeller hub) was making a local post-maintenance check flight with a pilot (23,000 hours total time) accompanied by a mechanic to record engine parameters. The 1957 built aircraft was not equipped with, nor was it required to have, a transponder.
Both aircraft were operating under Visual Flight Rules (VFR) in Class G uncontrolled airspace and were on converging flight paths in the Albertville valley at the, same altitude with a closing speed of c 280 kt. The helicopter crew described good visibility but heavy cloud cover. Despite both pilots monitoring the same radio frequency, neither was aware of the other’s presence until moments before the collision. The BEA recount:
At 11:45:53, the two pilots on board the helicopter perceived F-AYVV coming towards them, at the same altitude. The pilot flying sharply turned right while pitching down while the aeroplane continued in a straight line. The aeroplane pilot who saw the helicopter at the last moment, did not have the time to carry out an evasive action.
At 11:45:55, the tips of the helicopter’s [12.6 m diameter] main rotor blades came into contact with the aeroplane’s left fairing and made a cut in the root of the left wing, between the leading edge and the main spar (see Figure 1, point ❶).
The helicopter pilot started an emergency descent, reducing the speed to 80 kt. While searching for an obstacle-free area for landing, he transmitted a distress message by radio and activated the emergency locator transmitter. He landed in a field less than three minutes later (point ❷).
The helicopter’s landing gear sank into soft ground by c 10 cm. The damage was limited to the tips of two of the five main rotor blades, a notch on the trailing edge of one blade and blade rubbing marks the fenestron fairing that probably occurred during the landing.
After checking the controllability, the Nord [pilot initiated a descent, returning to Albertville aerodrome, landing five minutes later. Cuts were found cut on the left-hand side of the engine cowling and the left-hand wing leading edge down to the spar. The left-hand wing fuel tank was torn and the he left-hand aileron control rod was severed.
BEA Analysis
The collision took place in Class G uncontrolled airspace, not covered by a Flight Information Service (FIS), in a mountainous area. In this class of airspace, neither a transponder or radio calls are mandatory. Maintaining separation is based on the ‘see and avoid‘ principle.
See and avoid relies on flight crew monitoring and detecting nearby aircraft. The BEA highlight limitations in the event of:
- Low contrast between the aircraft’s colour and the background
- Aircraft closing in on a constant bearing as the lack of relative motion make them more difficult to detect
- Aircraft being masked by cockpit structure, the wing or engine cowling
BEA Conclusions
The limits of the see-and-avoid principle…may have contributed to the pilots’ late detection of a conflictual situation
As the two aircraft were closing in head-on, the visible profile of the helicopter and aeroplane was minimal, and visual detection was made all the more difficult by the fact that the two aircraft were approaching each other on a constant bearing.
Alternative Outcomes
Everyone survived this 8 February 2024 Mid Air Collision. A Mid Air Collision of two Airbus EC130B4s (VH-XH9 and VH-XKQ) over Main Beach, Gold Coast, Queensland, on 2 January 2023 tuned out differently.
Wreckage of the two EC130B4s on a Sandbar (Credit: ATSB)
The Australian Transport Safety Bureau (ATSB) issued their safety investigation report on 9 April 2025. While conducting scenic flights from the Sea World theme park the the helicopters collided at a height of 130 ft, around 155 m west-north-west of the Sea World Helicopters heliport.
The converging flight paths of EC130B4s VH-XKQ and VH-XH9 leading to the midair collision (Credit: ATSB)
ATSB report that:
Following the collision, VH-XKQ was uncontrollable and fell to the ground. The pilot and 3 passengers were fatally injured, 3 passengers were seriously injured, and the helicopter was destroyed. VH-XH9 was substantially damaged from the collision, but the pilot made a controlled landing. The pilot and 2 passengers were seriously injured, and 3 passengers had minor injuries.
ATSB summarised their investigation:
We will return to this ATSB article in a future article. We do note two findings with relevance to all air operator’s safety Management Systems (SMS):
- Sea World Helicopters’ implementation of their SMS did not effectively manage aviation safety risk in the context of the operator’s primary business. Additionally, their objectives were non-specific, and the focus of safety management was primarily ground handling and WHS [Workplace Health & Safety] issues. This limited the operator’s ability to ensure that aviation safety risk was as low as reasonably practicable.
- Sea World Helicopters’ change management process, conducted prior to reopening the park pad, did not encompass the impact of the change on the operator’s existing scenic flight operations. Crucially, the flight paths and the conflict point they created were not formally examined, therefore limitations of the operator’s controls for that location were not identified.
Our observation: The ATSB report is a reminder that safety critical decisions made on the basis of SMS processes can be re-examined by third-parties after accidents (including litigators, coroners and prosecutors after fatal accidents) and so need to stand-up without the added benefit of hindsight.
Safety Resources
The European Safety Promotion Network Rotorcraft (ESPN-R) has a helicopter safety discussion group on LinkedIn. You may also find these Aerossurance articles of interest:
Limitations of See and Avoid: Four Die in HEMS Helicopter / PA-28 Mid Air Collision
Alpine MAC ANSV Report: Ascending AS350B3 and Descending Jodel D.140E Collided Over Glacier
Mid-Air Collision of Guimbal Cabri G2 9M-HCA & 9M-HCB: Malaysian AAIB Preliminary Report
AAIB Highlight Electronic Conspicuity and the Limitations of See and Avoid after Mid Air Collision
Military Mid Air Collisions
Fatal Biplane/Helicopter Mid Air Collision in Spain, 30 December 2017
A319 / Cougar Airprox at MRS: ATC Busy, Failed Transponder and Helicopter Filtered From Radar
Mid Air Collision Typhoon & Learjet 35
UK CAA HOFO ACAS Rulemaking 2025 & a 2004 Tornado / AS332L Airprox
The UK Airprox Board (UKAB) has released videos with tips for pilots on preventing mid air collisions:
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