What happened
On March 23, 2014, a CAP-4 aircraft, registration PP-HJA, departed from the Aeroclube de Passo Fundo, RS, for a local flight. During the return to the airfield, the pilot attempted to switch fuel sources by selecting the upper tank. This action caused the engine to stop abruptly. The pilot subsequently performed an emergency landing in a soybean field. The pilot remained uninjured, and the aircraft sustained no damage.
The investigation
The investigation focused on the fuel system configuration and the pilot's positioning within the cockpit. The CAP-4 fuel system utilizes two tanks: an upper tank located in the cabin and a lower tank situated between the instrument panel and the firewall. Fuel selection is managed via a valve located behind the front seat, which features four settings: Upper, Both, Lower, and Off. When set to "Both," fuel from the upper tank is transferred to the lower tank.
Investigators determined that the pilot had used the "Both" setting to transfer residual fuel from the upper tank to the lower tank. Upon completion of the transfer, the pilot mistakenly selected the "Upper" position instead of the "Lower" position. Because the upper tank was already empty, the engine lost power. Furthermore, the investigation found that the pilot was operating the aircraft from the front seat. This contradicted the aircraft's specifications (EA-6501), which mandate that solo flights must be conducted from the rear seat, as indicated by a placard in the nacelle. This positioning obstructed the pilot's view of the fuel selector valve, contributing to the error.
Findings
- Improper cockpit positioning: The pilot was flying from the front seat, which is contrary to the aircraft's operating specifications for solo flight.
- Reduced visibility: The pilot's position in the front seat hindered the ability to clearly see the fuel selector valve.
- Pilot error: The pilot incorrectly selected the empty upper tank during the fuel transfer process.
- Flight indiscipline: Failure to adhere to established solo flight seat requirements.
- Judgment error: Errors in pilot decision-making during the fuel management sequence.