Fuel Exhaustion & Starvation · NTSB DCA22FA157
BEECH A35 — Centralia, IL
| Date | July 23, 2022 |
| Location | Centralia, IL |
| Aircraft | BEECH A35 |
| Purpose of flight | Personal |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Enroute Fuel starvation |
| Pilot age | 66 |
| Pilot total time | 419 hrs · Building experience |
| Time in type | 17 hrs |
| Fatalities | 1, 1 serious |
Probable cause
NTSB findings
- Personnel issues-Experience/knowledge-Experience/qualifications-Total experience w/ equipment-Pilot
- Aircraft-Fluids/misc hardware-Fluids-Fuel-Fluid management
- Aircraft-Fluids/misc hardware-Misc hardware-(general)-Incorrect service/maintenance
What happened
The pilot had purchased the airplane about 3 months before the accident and, according to his logbook, had accrued about 17 hours of flight experience in the airplane. The airplane departed for a cross-country flight with the fuel selector in the LEFT fuel tank position, which was consistent with guidance from the pilot’s operating handbook.
About 1 hour 13 minutes into the flight, as the airplane approached an airport while at 6,500 ft, the pilot attempted to switch to the RIGHT fuel tank. The pilot had wanted to switch fuel tanks “just in case” because he “didn’t trust the wobble pump” (a manually operated auxiliary fuel pump that is integrated with the fuel selector valve). He recalled that it was “hard to feel the detents” in the fuel selector valve and that it was “possible that it [the fuel selector valve] was not fully engaged.”
About 4 to 5 minutes after switching fuel tanks, the engine lost power. The pilot noted that the engine RPM was at 1,500 and believed that it had sufficient power to fly a traffic pattern to the runway. However, the engine was likely instead windmilling, with no power. The pilot turned around, flew past the nearest end of the runway at the airport he just overflew, and attempted to fly a left traffic pattern toward the runway’s opposite end. However, during the approach, the airplane “got too low,” and there was “no place to land.” The airplane continued to descend and then impacted terrain. The wreckage was located about 0.5 nautical miles north of the runway threshold.
After the accident, the pilot stated that, in hindsight, he should have made a straight-in approach to the nearest end of the runway and slipped the airplane to descend. Given the airplane’s altitude and proximity to the airport, had the pilot done this, it is likely that the airplane would have landed on the runway.
Examination of the airplane revealed that the fuel selector handle was not fully in the down position. When pushed fully downward, the fuel selector handle engages the fuel selector valve. When rotated in this position, the fuel selector handle can select either the LEFT or RIGHT fuel tank. When the fuel selector handle is pulled upward, it disengages from the fuel selector valve and can then be used as a manual fuel pump. Although the pilot reported using the handle in “pump mode” after the loss of power, the handle was also likely in “pump mode” when he rotated the handle to switch to the right fuel tank. While in this mode, rotating the handle would have no effect on the fuel selector valve, indicating that the handle likely remained in the LEFT fuel tank position. In addition, the pilot stated that it was difficult to detect the fuel selector valve detents, but postaccident examination showed that the detents could be felt when the fuel selector valve was engaged and rotated.
An electrical switch that was intended to warn the pilot, via a light on the instrument panel, when the fuel selector handle is not fully down and engaged with the fuel selector valve, was found not installed and stored in a map pocket in the cockpit. A Federal Aviation Administration airworthiness directive required the installation of this switch and cockpit warning light, (or the replacement of the selector valve/pump mechanism with one that has separate fuel selector and pump controls). If this switch had been installed, it would likely have warned the pilot that the fuel selector handle was in “pump mode” and was unable to change fuel tanks when rotated.
Fuel usage calculations indicated that the fuel burn for the flight was likely 16.2 gallons or greater, leaving less than 1 gallon of usable fuel in the left fuel tank. Therefore, the loss of total engine power was likely due to fuel starvation when all the fuel in the left fuel tank expended.