Accident to the Piper PA30 registered F-BPIR on 04/12/2023 at Villejuif

During the preflight check, the pilot in training probably omitted to put the fuel tank selectors in the MAIN position after having drained successively the MAIN and AUX fuel tanks. The Before start-up “checklist” was carried out under time pressure due to the CTOT slot for take-off coming to an end, and without the supervision of the instructor. The item of the “checklist” which consisted of making sure that the fuel tank selectors were correctly positioned to MAIN, was not checked.

The outbound and return flights were then carried out using the fuel in the AUX fuel tanks without the occupants being aware of this. The pilot in training and the instructor thought that they were carrying out the flight using the fuel in the MAIN fuel tanks, in accordance with the ATO’s practices which recommended their exclusive use for this type of flight. The fuel tank gauges were used neither on the ground or in flight.

During the descent to join the Toussus-le-Noble Intermediate Fix (IF) IN25R, in the cloud layer, the fuel system of each engine unprimed due to the fuel in the AUX fuel tanks having been completely used. The two engines no longer provided power. The instructor then took the controls and tried to restart the RH engine. He did not select a fuel tank containing fuel during his actions. He did not feather the propellers hoping to restart the engines and carried out a forced landing in the clean configuration, at night, in an urban environment.

The investigation was not able to determine what caused the untimely triggering of the stall warning for the last six to nine minutes of the flight when the aeroplane was in descent to start the approach. This warning probably generated a stressful situation and an additional workload, involving greater monitoring of the parameters, notably when conducting the forced landing.

In the scope of the IR/ME training given by the ATO, fuel management was simplified for short flights in order to allow the pilots in training to concentrate on the other aspects considered training priorities, such as the management of IFR procedures and controlling the flight with one engine inoperative. This simplification was based on the exclusive use of the MAIN fuel tanks in order to reduce the in-flight workload. The ATO “checklists” which differed from the flight manual procedures were consistent with this practice. This simplified approach may, however have led to a reduction in the pilot in training’s knowledge of the fuel system and decreased vigilance with respect to certain aspects of fuel management.