Accident Details
Probable Cause and Findings
A partial loss of engine power for undetermined reasons.
Aircraft Information
Registered Owner (Current)
Analysis
On June 30, 2024, about 1115 central daylight time, a Raytheon Aircraft Company A36, N47RT, was substantially damaged when it was involved in an accident near Land O’ Lakes, Wisconsin. The pilot and passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot reported that, during the initial climb, the engine exhibited a partial loss of engine power. She executed a forced landing into trees off the departure end of the runway, which resulted in substantial damage to both wings and the fuselage.
The pilot reported that the left fuel tank contained 30 gallons of fuel, and the right fuel tank contained 10 gallons of fuel. The pilot stated that she had selected the left fuel tank for takeoff. The fuel selector was found in the off position. Postaccident fuel levels were not confirmed on scene. The placard placed near the fuel selector states, “Do not take off if fuel quantity gages indicate in yellow band or with less than 13 gallons in each main tank.” The auxiliary fuel pump was found in the LOW position at the accident site. The pilot reported that it was positioned in the OFF position during the takeoff.
A review of the maintenance records revealed that the most recent annual inspection was dated July 1, 2024, the day after the accident. The signing Authorized Inspector stated that the annual inspection was completed on June 29, 2024, and that he mis-dated the entry.
A postaccident examination did not reveal any preimpact mechanical malfunctions or failures that would have precluded normal operation. The wings had been removed for transport. The right fuel tank, main supply, and vent lines were tested with pressurized air and no obstructions were noted. The left fuel tank was ruptured during the accident sequence and the main fuel supply line was bent and disconnected; however, no obstructions were observed in the separated line. No obstructions were found in the left fuel tank vent line.
The engine remained attached to the fuselage but was shifted forward and bent downward. The propeller remained attached to the engine and all three blades remained attached at the hub. All three blades were bent aft, one of which was bent midspan about 45°, consistent with little or little or no power being produced at the time of impact.
Three postaccident engine runs were conducted. During the first engine run, the engine started, idled, and accelerated without hesitation. During the second engine test run, the auxiliary fuel pump was moved from the OFF to the LOW and HIGH switch positions while the engine operated near the red line, as indicated by the manifold pressure gauge. No noticeable changes were observed. When the throttle was reduced to about 1,000 RPM and the auxiliary fuel pump was in the LOW position, it ran slightly rough; in the HIGH position, the engine ran noticeably rougher. For the third engine run, a portable optical tachometer was used; when the engine ran at full power, the portable tachometer indicated a maximum rpm of 2,600.
The fuel selector valve was tested with pressurized air from the left and right main fuel lines and no anomalies were found. The fuel pump, fuel control unit, and the fuel flow divider were tested at Continental Aerospace Technologies in Mobile, Alabama, and no anomalies were found that would have precluded the engine from producing the full rated horsepower.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# CEN24LA245