Incident Description
On 11 August 2020, at approximately 15:50 UTC, a Diamond DA-42 aircraft, registration SP-TRL, was conducting an IFR training flight on the route from EPBC to EPMO and returning to EPBC. During vectoring for the ILS approach to runway 08 at EPMO, the left engine momentarily lost power. After all engine parameters returned to normal, the commander decided to abort the task and return to EPBC at a safe altitude. The crew informed AFIS Warsaw of the situation. The aircraft landed without incident on runway 10 at EPBC at 16:13 UTC. While turning 180 degrees on the runway, the left engine shut down, preventing the aircraft from vacating the runway and blocking it for approximately five minutes.
Investigation Findings
A post-flight inspection revealed that the flexible fuel hoses were incorrectly connected at the fuel tank. The fuel supply hose was connected to the return port, and the return hose was connected to the supply port. This configuration caused fuel to be drawn from the top of the tank rather than the bottom. The left engine shut down when the fuel level dropped below the connection point of the return hose. The reverse installation likely occurred during the last structural inspection of the airframe after 1,000 flight hours.
Probable Cause
The probable cause of the incident was the reverse connection of the flexible fuel hoses (supply and return) to the fuel tank.
Safety Recommendations
The aircraft operator was recommended to mark the fuel tank ports and hose end fittings with different colors during the next scheduled maintenance to prevent recurrence. No additional safety recommendations were formulated by the commission.