What happened
On 28 March 2022, an Airbus Helicopters EC145 (registration EC-MSD), operated by Babcock for emergency medical services, was returning to its operational base at Tenerife Sur-Reina Sofía Airport. After completing a patient transport flight from El Hierro, the crew proceeded to the K3 helipad on the airport's restricted-use emergency apron.
During the air taxi maneuver to the parking stand, the crew attempted to orient the helicopter with its tail toward a garden to facilitate easier access for ground personnel. However, the aircraft encountered significant wind conditions, with surface winds reported at 26 knots and gusts up to 31 knots. As the co-pilot struggled to stabilize the aircraft, the captain took control of the flight controls. During this transition, the helicopter experienced intense vibrations and the autopilots disengaged. The aircraft climbed and performed a 180-degree turn, causing the tail rotor to strike the branches of a nearby tree. The captain immediately performed an emergency landing on the helipad.
The investigation
The CIAIAC examined the flight data recorder (FDR) and cockpit voice recorder (CVR) to reconstruct the sequence of events. The investigation established that the positioning maneuver was prolonged due to instability caused by the wind. The investigation also reviewed the aircraft's maintenance history and the operational procedures of the operator. Investigators noted that while the crew was aware of the high winds, the desire to prioritize ground personnel safety and operational efficiency led them to attempt a landing orientation that was difficult to maintain under the prevailing meteorological conditions.
Findings
- The crew intended to position the helicopter facing the service building to enhance safety for ground support staff.
- The strength and direction of the wind were known to the crew prior to the maneuver.
- The aircraft became unstable during the positioning maneuver on the K3 apron.
- The crew failed to adequately account for the strong wind while positioning the helicopter above the parking apron.
- The captain took over the flight controls with low awareness of the existing instability condition of the helicopter.
- The tail rotor struck tree branches, leading to damage to the tail rotor blades, the vertical stabilizer, and the partial detachment of the tail rotor gearbox.