ERA21LA081 · Piper PA28 140

During an instructional flight, the flight instructor noted that the flight was getting low during final approach and instructed the student pilot to add power, which he did; however, the engine did not respond. The flight instructor assumed control of the airplane and attempted to restore power but was unable to do so. The airplane subsequently impacted a utility pole and power lines during a forced landing. A postimpact fire ensued, and the airplane fell to the ground.

Postaccident examination of the engine revealed no evidence of any mechanical anomalies that would have precluded normal operation. Examination of the airframe revealed that the fuel selector was in the OFF position. During the approach and forced landing, the student pilot was not instructed to move, and was not observed moving, the fuel selector to OFF, and he did not recall doing so. The student pilot had repositioned his seat during the final approach. The passenger (in the rear seat) noticed that the loss of engine power occurred shortly after the student pilot had repositioned his seat and that the fuel pressure indicated zero just before the impact with the power lines. Given all available information, it is likely that the student pilot moved the fuel selector inadvertently to the OFF position when he repositioned his seat before the approach. The incorrect fuel selector position led to fuel starvation and a total loss of engine power.

The fuel selector was located on the airplane’s left sidewall near where the left seat pilot’s knee would be positioned. The fuel selector cover and bezel allowed the pilot to freely rotate the handle through its four positions (right tank, left tank, and two OFF positions) with no safety provision to prevent the handle from being inadvertently moved to one of the off positions. The fuel selector was the original model design. The airframe manufacturer had twice upgraded the fuel selector design; the most recent design required the pilot to depress a spring-loaded stop while positioning the fuel selector to OFF to prevent the inadvertent selection of that position. The manufacturer issued a service bulletin to upgrade fuel selectors from the original to the most recent design, but the Federal Aviation Administration did not issue an airworthiness directive, which would have required operator compliance with that service bulletin. Examination of the accident airplane’s logbook revealed that the fuel selector was replaced during the last annual inspection (about 3 months before the accident); however, the replacement fuel selector, including its cover and bezel, had the original design. Had the fuel selector in the accident airplane been replaced with the newer model, rather than the original model, it is possible that the inadvertent movement of the fuel selector to the OFF position might not have occurred.

Verbatim NTSB analysis and probable cause from the NTSB dataset