What happened
On July 22, 2019, a Robinson R66 helicopter, registration RA-07370, crashed into the Tyrrhenian Sea approximately 6 nautical miles southwest of Gorgona Island. The aircraft had departed from Massa Cinquale for a private landing site in Porto Cervo, flying under Visual Flight Rules (VFR) at an altitude of approximately 500 feet. During the flight, the engine suddenly shut down, causing the helicopter to impact the sea with high vertical and forward velocity. While the passenger was found deceased inside the wreckage, the pilot was lost at sea.
The investigation
The ANSV investigation focused on the engine and the flight sequence. Analysis of the Engine Monitoring Unit (EMU) confirmed a sudden engine shutdown consistent with a sudden interruption of fuel supply. While the fuel level was sufficient for the flight duration, the exact cause of the fuel interruption could not be determined. The investigation examined the engine components, noting that while the fuel pump showed damage, this was attributed to the impact rather than a pre-existing failure.
Investigators also reviewed the pilot's actions and the aircraft's configuration. The aircraft was equipped with emergency pop-out floats, which were found floating with the wreckage, though there was no evidence the pilot had manually deployed them. Furthermore, the ignition key was found in the 'OFF' position, which would have prevented any attempt at an in-flight restart.
Findings
- The engine experienced a sudden shutdown that appeared to be caused by a sudden interruption of fuel supply.
- The pilot likely failed to transition effectively to an autorotation maneuver following the engine failure.
- The impact dynamics suggest the pilot did not sufficiently reduce the rate of descent or forward speed, as evidenced by the lack of decoupling between N1 and N2 engine speeds on the EMU.
- The 'surprise effect' of the sudden engine failure may have caused a delayed response to the emergency.
- The ignition key was in the 'OFF' position, precluding an in-flight restart attempt.
- Environmental conditions were clear with excellent visibility and did not contribute to the accident.