Incident Details
On 23 September 2020, a crew consisting of a student and an instructor departed from Warsaw Babice Airport (EPBC) in an AT-3 R100 aircraft, registration SP-TPE, for a training flight. Approximately 30 minutes into the flight, a 'check fuel pressure' alert appeared and fuel pressure indications dropped to nearly zero. The crew activated the electric fuel pump, and the fuel pressure returned to normal. They declared an emergency with Flight Information Service (FIS) and returned to the airport. During the return, fuel pressure remained within normal limits. Near the airport, the crew turned off the electric pump for about 10 seconds to test the system; fuel pressure indications remained correct.
Cause
The investigating authority determined the incident was caused by a defective engine-driven fuel pump.
Preventative Actions
The aircraft manufacturer was informed of the incident. Following the manufacturer's recommendation, the fuel pump was replaced. Ground tests were conducted and the malfunction did not recur. The manufacturer is currently pursuing approval of a fuel system modification to eliminate similar occurrences in the future.