Flight History
On 5 March 2021, a Diamond DA40 NG registered F-HRPM, operated by Cannes Aviation Academy, was conducting an instructional flight. The aircraft departed Cannes Mandelieu airport in the afternoon for Ajaccio Napoléon Bonaparte airport, where it refueled. After a touch-and-go at Calvi Saint-Catherine airport, the flight began the return to Cannes. At approximately 18:02, while en route at FL060 about 40 NM from the Corsican coast, engine power suddenly decreased without warning. The instructor performed the checklists for loss of engine power and attempted an inflight restart with propeller windmilling, but with no effect. She sent a Mayday message to Nice approach and turned back toward Corsica. At 18:11, she ditched the aircraft approximately 30 NM northwest of the coast.
Occupants and Training
On board were a 35-year-old instructor who held a CPL(A) with ratings including CRI(A) and IR/ME, and had about 3,000 flight hours. The pilot flying was a 24-year-old holding a PPL(A) with 141 flight hours, including 39 as PIC. The rear-seat pilot was a 29-year-old holding a PPL(A) and nearing the end of IR(A) training. All three evacuated the aircraft and entered a life raft.
Meteorological Conditions
Météo-France estimated wind from 270° at 10 kt, visibility greater than 10 km, occasional showers north of the ditching zone, sky clear to few clouds, temperature 13 °C, dewpoint 9 °C, QNH 1017. The sea was smooth with a 265° swell less than 0.6 m and a slight current. Water temperature was 13.8 °C. Aeronautical night began at 18:51, about 40 minutes after ditching.
Statements
The pilot recalled that after takeoff from Calvi, engine indications were normal. En route, the instructor conducted a knowledge exercise covering engine parameters. After a frequency change, the crew heard an aural alert and saw “ECU A fail” and “ECU B fail” on the PFD. The pilot felt the engine stop abruptly and the aircraft yaw left. The instructor noted all engine parameters stayed in the green, no other alerts, and the propeller windmilled until ditching. She initially questioned whether it was an exercise. She disconnected the autopilot and took control. The pilot ran the ECUA FAIL, ECUB FAIL, and engine restart checklists three times with no result. The MFD showed Calvi 41 NM away versus Nice 50 NM; the instructor decided to return to Corsica.
Examination and Cause
The wreckage was not recovered due to sea depth (2,500–3,000 m). A fault tree analysis, supported by the engine and aircraft manufacturers, could not determine the cause of the sudden power loss. However, it was considered probable that only a malfunction in the high-pressure fuel system could have led to the reduction. Possible components included the high-pressure fuel pump, its driving gear, pressure control valve, wiring, fuel flow metering unit, or supply system. A leak in the high-pressure fuel system was also not excluded.
Survival and Rescue
After ditching, the three occupants evacuated into a life raft. At 18:17, the pilot of an APM 30 (F-HNIZ) located them and relayed their position. Rescue services arrived at 18:55 and hoisted them into a helicopter at night, a little over two hours after the accident. The instructor sustained injuries; the aircraft was destroyed.
Engine Information and Service Bulletins
The aircraft had been fitted with a new Austro Engine E4-A (S/N 323) on 21 January 2021, accumulating 42 flight hours before the accident. Between August and November 2021, Austro Engine issued several Mandatory Service Bulletins (MSB-E4-034/3, MSB-E4-035/1, MSB-E4-036/1) addressing potential failure of the high-pressure fuel pump driving gear, which could cause loss of common rail pressure and engine shutdown. EASA adopted these via Airworthiness Directives. The engine of F-HRPM was equipped with the type of pump and cylinder head concerned by these bulletins.