CEN22LA040 · Beech 23

The flight instructor completed about a 1-hour instructional flight with a student pilot, then was able to add only 4.19 gallons of fuel due to an issue with the airport’s fuel pump. The flight instructor then completed another 1-hour flight with a second student pilot. During this flight they used both fuel tanks, switching between tanks about every 30 minutes, and the flight instructor thought there would have been about 11 gallons remaining in the left tank and about 3 gallons in the right tank. They had completed one touch-and-go landing, then after takeoff, about 500 ft above ground level, the engine sustained a loss of power. The flight instructor took control of the airplane and requested that the student pilot complete the emergency checklist for a loss of engine power. They were unable to restart the engine and made an emergency landing to an area of mesquite trees. The airplane sustained substantial damage to the wings, fuselage, and empennage. The initial postaccident examination revealed that the wing fuel tanks were breached during the impact with trees and there was no sign or smell of residual fuel at the accident site. A detailed examination of the engine and fuel system did not reveal any residual fuel in the fuel system or engine components, and there were no anomalies found that would have precluded normal operation. The airplane manufacturer issued service instructions in 1974 that increased the amount of total unusable fuel from 1 gallon to 7.6 gallons (3.8 gallons per tank). The instructions had not been complied with since there were no updated placards to indicate 26 gallons of usable fuel for each tank. A postaccident fuel consumption estimation was completed based on the available evidence, which concluded that there could have been up to 7.79 gallons of usable fuel available. Since there was no recorded engine data, fuel quantity data, fuel at the accident site, or fuel remaining the airplane, the investigation was unable to determine the exact amount of usable fuel available, if any, when the loss of engine power occurred. It is likely that the flight instructor’s misunderstanding of the usable fuel quantity, and his inadequate management of the available fuel, resulted in fuel starvation and a loss of engine power.

Verbatim NTSB analysis and probable cause from the NTSB dataset