What happened
On 26 March 2015, an Airbus helicopters AS 355 NP, registration EC-KYJ, operated by TAF Helicopters for the Catalonia Regional Police, was performing a surveillance mission. During the cruise phase of the flight, a CHIP 2 warning light illuminated in the cockpit, indicating the presence of metal particles in the right engine. The pilot noted that the right engine oil pressure had risen to 12.3 bars, exceeding the maximum limit of 10 bars.
Rather than following the flight manual's requirement to shut down the engine, the pilot placed the right engine in training (TRNG) mode to reduce vibrations and power demand. The pilot then diverted from the original destination to the Catalonia Race Track helipad to perform a landing. During the short final approach and landing flare, as power was demanded from the engines, the right engine suffered a catastrophic failure. A portion of the power turbine and the exhaust pipe detached, causing the power turbine shaft to be ejected. This event damaged several components, most notably shearing the tail rotor shaft and causing the aircraft to lose yaw control.
Following the landing, the right engine caught fire. The crew and passengers successfully evacuated the aircraft without 0 injuries. The occupants used onboard fire extinguishers and assistance from a track service truck to extinguish the flames, which had begun to spread toward the left engine.
The investigation
The investigation focused on the mechanical failure of the engine and the pilot's management of the emergency. Investigators examined the engine's lubrication and fire detection systems, the wreckage, and the flight recorder data. Technical analysis was performed on the turbine drive shaft and the engine's thrust bearing. The investigation also reviewed the pilot's adherence to the flight manual's emergency procedures regarding the CHIP 2 warning.