Accident Overview
On an instrument flight rules flight from Calgary International Airport (CYYC), Alberta, to Hinton/Entrance Aerodrome (CEE4) and back, a Piper PA-31 Navajo operated by Airborne Energy Solutions Inc. experienced a dual engine failure during the final approach to CYYC, resulting in a forced landing on a golf course south of Runway 35R. The aircraft came to rest approximately half a nautical mile south of the threshold of Runway 35R. The pilot, the sole occupant, received minor injuries. There was no post-accident fire. The aircraft sustained substantial damage.
Flight Details
The planned round robin flight included a leg from CYYC to CEE4 and a return to CYYC without refueling at CEE4. Before departing from CEE4, the pilot determined that sufficient fuel was available for the return flight. During cruise, the left engine experienced fluctuating fuel pressure and erratic operation while being supplied by the left outboard tank. The pilot switched the left engine to the left inboard fuel tank. Concerned about fuel quantity in the left-wing tanks, the pilot elected to cross-feed the left engine from the right-side fuel system.
Engine Failure Sequence
During the final approach into CYYC, the right engine stopped running. The pilot secured the right engine, feathered its propeller, declared a Mayday with air traffic services, and chose to continue the approach. Two to three minutes later, the left engine also stopped operating. The pilot then executed a forced approach onto a golf course located directly south of the approach end of Runway 35R.
Emergency Landing
The forced landing was conducted without further incident. The aircraft came to rest on the golf course, south of the runway threshold. Emergency services responded, and the pilot was reported to have minor injuries.
Post-Accident Examination
On-site examination of the aircraft revealed the left-hand fuel selector in the outboard position, the right-hand fuel selector in the off position, and the cross-feed valve in the off (normal) position. Fuel recovery showed no fuel remaining in the left inboard, left outboard, and left nacelle fuel tanks. The right nacelle tank was empty, while approximately 24 US gallons were recovered from the right inboard tank and approximately 29 US gallons from the right outboard tank. The aircraft was subsequently transported to a secure location for further investigation.