What happened
On December 9, 2010, a Piper PA-30, registration PT-WJW, was performing a check flight for a multi-engine rating when it experienced a total loss of power. The flight originated from Caldas Novas (SBCN) and was bound for Goiânia (SBGO). During the descent into SBGO, the left engine failed. Approximately five minutes later, the right engine also stopped functioning.
Unable to restart the engines, the crew performed a forced landing in a flat, unobstructed field near Fazenda Bela Vista, Goiás. The aircraft landed with the landing gear extended and locked. All three occupants—the pilot, the instructor, and a passenger—emerged uninjured, and the aircraft sustained no damage.
The investigation
CENIPA's investigation focused on why both engines failed despite the presence of usable fuel in the auxiliary tanks. The investigation established that the aircraft had been flying for approximately two and a regular half hours, utilizing only the main fuel tanks. Because the flight involved various power settings and maneuvers, the actual fuel consumption had likely increased, exhausting the main tanks sooner than anticipated.
Investigators found that while the auxiliary tanks were full, the crew failed to switch the fuel selectors to the auxiliary position before the main tanks ran dry. Furthermore, when attempting to restart the left engine, the crew moved the fuel selector to the 'AUX' position but failed to verify the position of the wingtip tank switches. These switches were set to 'ON', which directed the fuel flow from the wingtip tanks, which were already empty.
Additional complicating factors included unreliable fuel gauges, which the pilots were aware of, and a lack of standardized procedures within the flight school regarding the specific timing for switching between main, auxiliary, and wingtip tanks.
Findings
- Improper fuel management was the primary cause, as the crew did not monitor fuel consumption or plan the transition between tanks.
- Inadequate situational awareness regarding remaining fuel levels, exacerbated by unreliable fuel gauges.
- Incorrect fuel system configuration during the engine restart attempt, specifically failing to check the wingtip tank switches.
- Lack of standardized procedures for fuel tank selection during different phases of flight.