Event Summary
On 2 July 2021 at 17:30 UTC, a Eurocopter (Airbus Helicopters) AS350 B3 helicopter, registration I-TNLD, was returning from aerial work in Borgo Valsugana to its base at Trento's Caproni Airport. After a stop at Vigolo Vattaro to drop off one of two crew assistants, the helicopter departed for the final leg of about 3 NM. Shortly after takeoff, the pilot observed the red GOV warning light illuminate, accompanied by an audible warning and the FLI FAILED indication on the VEMD.
To manage the malfunction while maintaining parameters within limits, the pilot gained approximately 2000 ft of altitude. After regaining control, he continued the flight. During the downwind and base turn, while in contact with the AFIU at Trento, at about 300 ft altitude the pilot perceived a sudden drop in main rotor RPM and initiated an autorotation. The helicopter impacted a relatively obstacle-free area, but during landing the tail struck a small tree and the fuselage came to rest on a flowerbed near the SS12 road.
The crew assistant evacuated the helicopter unaided, while the pilot was rescued by bystanders. Both were transported to a hospital and admitted with serious injuries. The helicopter sustained serious damage from the hard landing, vegetation impact, and ground resonance-induced blade strikes.
Aircraft Information
The AS350 B3 is a light multirole helicopter with a metal structure, skid landing gear, and a maximum takeoff mass of 2250 kg. It is powered by a Turbomeca Arriel 2B engine. The accident aircraft, I-TNLD (serial number 3383), was first registered in 2001 and operated by the Autonomous Province of Trento (Nucleo elicotteri VVF). The operator held COA, COAN, and CAMO approvals for continuing airworthiness and was authorized by ENAC for high-risk specialized commercial operations.
The helicopter was equipped with a Vehicle and Engine Multifunction Display (VEMD) and a Digital Engine Control Unit (DECU) capable of recording fault and exceedance data. The Airworthiness Review Certificate was valid until 22 May 2022.
Personnel
The pilot, aged 41, held a valid CPL(H) with ratings for AS350, EC130, AW109 (IR), mountain aerial work, paradropping, and radiotelephony (English and Italian, Level 4). He had logged 3867 hours total, with 3617 on AS350 type. In the last 12 months he flew 221 hours; in the last 30 days about 32.5 hours. He joined the operator on 1 May 2021, completed conversion training from 3–7 May, and an Operator Proficiency Check (OPC) on 18 May 2021 on an AS350 B3 (I-TNAA). Notably, the OPC aircraft had a different governor and twist-grip collective system than I-TNLD. After the OPC, he flew mainly I-TNAA until 16 June, then exclusively I-TNLD until the incident.
The crew assistant, aged 56, had been employed by the helicopter unit for about 22 years, serving as a technician for aerial work and HEMS. He had completed courses on SA313/318, SA315, AS350, and AS365 helicopters.
Flight Details
The flight was an operational transfer under Visual Flight Rules (VFR) at the end of a day of aerial work. The initial malfunction prompted the pilot to climb to about 2000 ft above departure elevation. After troubleshooting, he proceeded toward Trento. On final approach, while turning base at approximately 300 ft, the rotor RPM decayed rapidly, forcing an autorotation. The impact sequence resulted in substantial damage, but both occupants survived with serious injuries.
Probable Cause
The investigation report does not state a probable cause; therefore, none is provided.