CEN21LA151 · Beech 35 UNDESIGNAT

The airplane was recently purchased by the copilot. The day before the accident, a mechanic performed a pre-buy/annual inspection on the airplane, which had not been inspected in over 8 years, with no issues annotated in the maintenance records. On the day of the accident, the pilot and copilot departed for the cross-country flight of about 200 nautical miles to the copilot’s home airport. The copilot reported a total of 54 gallons of fuel between the three fuel tanks (17 gallons each in the left and right tanks and 20 gallons in the auxiliary tank) at departure. He also reported that the generator was inoperative, and the flight was made with the retractable landing gear in the extended position. About 43 minutes into the flight, the fuel in the left-wing fuel tank was “depleted,” and the crew switched to the right-wing fuel tank with no issues. The pilot suggested they switch to the auxiliary fuel tank, and when the copilot switched to the auxiliary fuel tank, a total loss of engine power occurred. The copilot switched the fuel selector to its “opposite position” and then switched it back to the right fuel tank but power was not restored. The crew attempted to restart the engine several times with no success, and the pilot transferred the flight controls to the copilot for a forced landing. The copilot maneuvered the airplane through a canopy of trees, and the airplane then impacted the ground resulting in substantial damage to both wings and the fuselage. During postaccident examination, the required fuel selector placard depicting the four selectable positions (RIGHT TANK, LEFT TANK, AUXILIARY TANK, and OFF) was not observed in the wreckage. The fuel selector was found with the handle between the OFF and LEFT TANK positions; in this position, fuel would not pass through the selector. Detents that should have been felt at the four selectable positions were not noted as the handle was rotated through the fuel tank positions. The mechanic reported there were no issues noted with the airplane during the annual inspection performed one day before the accident and the mechanic classified the airplane as “complete.” None of the three fuel tanks contained observable fuel levels on scene. There was no evidence of fuel spillage, smell, or vegetation blighting at the accident site. The right-wing and auxiliary tanks were not breached. The left-wing bladder was punctured by a fracture in the inboard wing rib that likely occurred during impact. Although the copilot reported that the fuel selector placard was installed, review of his cell phone records indicated that during the flight, he sent a text message to the previous airplane owner asking what position on the fuel selector was for the auxiliary fuel tank. Therefore, it is likely the fuel selector placard was not installed in the airplane. The text message also indicates the flight crew lacked an understanding of how to properly operate the fuel selector. According to the copilot, there should have been fuel available when the engine power loss occurred. Based on the examination of the fuel system, the reason for the lack of fuel at the accident site could not be determined. Given that the fuel selector was found in a position where fuel would not pass through it, that the fuel selector placard was not installed, and that the flight crew lacked adequate knowledge of fuel selector operation, it is likely the flight crew incorrectly placed the fuel selector between the fuel tank detents, which resulted in a loss of engine power. The airframe manufacturer issued a service bulletin 23 years before the accident about adding an updated placard to the fuel selector due to reports of incidents and accidents involving engine failure due to pilots incorrectly positioning the fuel selector between fuel tank detents. The service bulletin stated that a no-flow condition exists between the fuel tank detents. The airplane maintenance records did not show that this service bulletin was complied with, nor was it required to be complied with. Based on autopsy findings, the pilot had severe atherosclerotic disease in his left anterior descending coronary artery. Although this condition placed him at an increased risk for a sudden incapacitating event, including a heart attack, stroke, or arrhythmia that could cause acute symptoms without leaving evidence on autopsy, his autopsy did not show any evidence of an acute event. Additionally, the surviving copilot did not report that the pilot had experienced an impairing or incapacitating event, and they were both making efforts to correct the power loss and land the airplane. The autopsy also noted evidence of medical intervention on the fatally injured pilot. Atropine, a drug used for resuscitation that was detected on toxicology testing, was likely administered in life-saving efforts. Thus, the pilot’s cardiovascular condition would not have contributed to this accident, and the detection of atropine was from postaccident treatment.

Verbatim NTSB analysis and probable cause from the NTSB dataset