ERA25LA142

The pilot reported that he was flying to the surveying location about 1,800 ft mean sea level (msl) for about 10 minutes after departing when the engine “just stopped.” He stated that there were no indications of an engine problem until it suddenly lost total power. He switched the fuel tanks and verified the magneto switch position, but the engine did not regain power. He attempted a forced landing in a field but, as the airplane touched down, the left wing contacted trees and stopped the airplane abruptly. The left wing was substantially damaged, and fuel began to leak into the cabin. The pilot and pilot-rated passenger exited through the aft door and called the departure airport’s air traffic control tower for assistance. Postaccident examination and an engine test run revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. Data recovered from the engine data monitoring device installed in the airplane showed that the engine consumed about 10 gallons per hour (gph) more fuel than indicated by the calculations in the Pilot’s Operating Handbook (POH) when the airplane was at a cruise altitude of 1,700 ft mean sea level (msl). The fuel flow increased above that previously established level just before the engine stopped producing power. With the data showing a high fuel flow spike just before the loss of engine power, and the pilot indicating that the mixture lever had been set to the full rich position since takeoff, the spike was likely the result of the higher-than-recommended mixture setting and inadvertent activation of the airplane’s auxiliary fuel pump, which enrichened the fuel-to-air mixture past the point of the engine’s combustion capability. This condition was the subject of a note in the airplane’s POH.

On March 12, 2025, about 1450 eastern daylight time, a Cessna TU206G, N27GP, was substantially damaged when it was involved in an accident near Wedgefield, Florida. The private pilot and a pilot-rated passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 aerial observation flight. According to the pilot, he was flying southeast after departing Orlando Executive Airport (ORL), Orlando, Florida, to the surveying location about 1,800 ft agl for about 10 minutes when the engine “just stopped.” He stated that there were no indications of an engine problem until it suddenly lost total power. He switched the fuel tanks and verified the magneto switch position, but the engine did not regain power. He attempted a forced landing in a nearby field that appeared to be long enough. After the airplane touched down, the left wing contacted trees, stopping the airplane abruptly. The left wing and fuselage were substantially damaged, resulting in a fuel leak in the cabin. The pilot and pilot-rated passenger exited the airplane through the aft door and called the ORL air traffic control tower for assistance. In an interview with the pilot, he described the power settings at the time of the accident as 2,400 rpm and 27 inches of manifold pressure. He also stated that the mixture lever was at the full rich position since takeoff. Postaccident examination of the wreckage found that the master switch and auxiliary fuel pump switches were in the Off position. The throttle lever was in the idle position. The propeller and mixture levers were in the full forward positions. The fuel selector handle was in the Off position. A J. P. Instruments EDM-830 device and a Sentry Plus FFSEN3 were recovered and sent to the NTSB Recorders Laboratory for data extraction. Data from the EDM-830 revealed a spike in fuel flow and a decrease in engine rpm before a total loss of engine power occurred. The data showed that the engine operated at 2,488 rpm and 28 inches of manifold pressure from 1441:57 to 1447:42. In the same period of flight data, fuel consumption fluctuated between 24.7 gph and 28.7 gph. At 1447:47, the fuel flow climbed to 38.7 gph and the engine dropped to 2,050 rpm. The fuel flow remained above 30 gph until 1449:42, when the engine dropped to 1,367 rpm. The engine dropped to 0 rpm over the next 20 seconds. The POH for this airplane model indicated that at a pressure altitude of 2,000 ft, 2,500 rpm, and 28 inches of manifold pressure for standard temperature, the engine consumed 16.1 gph in cruise flight. A note in the POH stated, “If the engine-driven fuel pump is functioning and the auxiliary fuel pump switch is placed in the On position, an excessively rich fuel/air ratio is produced unless the mixture is leaned. Therefore, this switch should be turned off during takeoff.” According to Textron Aviation, the type certificate holder for this airplane, there are different scenarios, conditions, or reasons for turning theelectric auxiliary fuel pump on, but it is typically in the Off position for normal cruise flight. The auxiliary fuel pump switch is a red and yellow split-rocker switch. The yellow right half is labeled Start, and its upper On position is used for normal starting, minor vapor purging, and continued engine operation in the event of an engine-driven fuel pump failure. With the right half of the switch in the On position, the pump operates at one of two flow rates, which are dependent on the throttle setting. With the throttle open to a cruise setting, the pump operates at a high enough capacity to supply sufficient fuel flow to maintain flight with an inoperative engine-driven fuel pump. When the throttle is in the closed position, such as during letdown, landing, or taxiing, the fuel pump flow rate is automatically reduced, preventing an excessively rich mixture during these periods of reduced engine speed. The red left half of the switch is labeled Emerg, and its upper Hi position is used in the event of an engine-driven fuel pump failure during take-off or high-power operation. When the spring-loaded left half of the switch is released, the right half remains in the On position until manually returned to the Off position. A postaccident examination of the airplane and engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The pilot did not report any controllability issues with the airplane. An engine test run was performed using the airplane’s fuel system through the right wing attachment point with no anomalies found. There were no visual discrepancies observed with the engine before the test run. The engine’s fuel injection system was pressurized using the airframe’s auxiliary fuel pump and no leaks were observed. The engine test run was limited to 1,700 rpm as a result of excessive vibration from a bent propeller blade, which was bent aft 20° at about the midspan of the blade. The two remaining propeller blades were undamaged. The left and right wing fuel tank strainers were found to be clean and unobstructed. The fuel vent system was found to be unobstructed. The left wing root main fuel line to the fuel line downstream of the fuel strainer bowl was found to be unobstructed and contained aviation fuel consistent with 100LL. A fuel sample was taken from the fuel strainer bowl, and no water was detected with the use of water detection paste. The fuel strainer bowl and filter were not removed. The airplane was equipped with auxiliary wingtip fuel tanks, each with a capacity of 15 gallons, 14.9 gallons of which were useable. The fuel indicators for both tanks read 0. The left and right tip tank fuel pump switches were found in the Off position. A review of the operator’s Standard Operating Procedures revealed that “initial or annual recurrent training shall consist of at least the following: Company Standard Operating Procedures Manual, aircraft type and aircraft systems,emergency procedures, flight planning, human factors, workload and time management in aircraft, effects of fatigue on performance, avoidance strategies, and mitigations.” When the operator was asked to provide the training record documentation for the pilot, they were unable to provide documentation of proof of training for the accident aircraft type and aircraft systems. A copy of a training certificate for the pilot dated 2023 in a PA31-325 was the only documentation provided. Additionally, when questioned about an excessively rich fuel mixture as a result of operating the auxiliary fuel pump in flight, the operator’s flight director was unaware of the notation in the POH stating that if the engine-driven fuel pump is functioning and the auxiliary fuel pump switch is placed in the On position, an excessively rich fuel to air ratio is produced unless the mixture is leaned.