WPR22LA083

The pilot reported that, during previous flights, he had observed overheating of two of the engine cylinders, and activation of the auxiliary fuel boost pump had worked to resolve the overheating. Shortly after takeoff on the accident flight, the pilot observed cylinder heating and activated the boost pump, after which the engine lost total power. The pilot performed a forced landing in an open desert field. The airplane landed hard and impacted vegetation during the landing roll, resulting in substantial damage to the airplane. Data retrieved from the airplane’s engine monitoring system showed that the fuel flow rate increased from 23.4 gallons per hour (gph) to 28.7 gph, with a peak fuel flow of 30.8 gph, followed by a sudden decrease. The engine manufacturer recommended that the fuel flow setting should be between 23.2 – 24.9 gph. Both the pilot operating handbook for the airplane and a placard on the auxiliary boost pump indicated that the pump should be off during takeoff and only turned on in the event of a loss of fuel pressure. It is likely that the pilot’s activation of the auxiliary fuel boost pump resulted in excess fuel being delivered to the engine during the initial climb, which resulted in the total loss of engine power. A postaccident examination of the airframe and engine revealed no evidence of mechanical failures or malfunctions that would have precluded normal operation.

On January 26, 2022, about 1055 mountain standard time, a Beech F33A airplane, N1HH, was substantially damaged when it was involved in an accident near Williams, Arizona. The pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he departed and turned left to the west. While climbing through about 700 to 800 ft above ground level, the engine lost power and the pilot initiated a right turn back toward the airport. The pilot stated that he realized he was unable to make it to the airport and elected to land in an open desert field. The airplane subsequently landed hard and impacted vegetation during the landing roll. The pilot stated that he had topped off the right fuel tanks before the flight and that the fuel selector was placed to the right main tank position. On previous flights, the pilot had observed “minor heating” in two of the engine cylinders and informed his mechanic. His mechanic directed him to turn on the fuel boost pump when the pilot observed the overheating, and the pilot stated that this method had “worked great until the day of the accident.” On the day of the accident, the two cylinders began to heat up, and the pilot activated the boost pump. Shortly thereafter, the engine lost total power. The mechanic reported that the pilot was “in a rush” to take possession of the accident airplane and indicated an urgent desire to fly from Arizona to California. After releasing the airplane, the pilot called and indicated that the airplane "was running great, but cylinder number 2 was still running ‘Hot’." The mechanic suggested that the pilot note exhaust gas temperature (EGT), cylinder head temperature (CHT), and fuel flow indications and bring the accident airplane in for further maintenance. He did not recall suggesting that the pilot use the auxiliary fuel boost pump during takeoff or climb. The airplane was equipped with an electric auxiliary fuel boost pump that could be manually activated by the pilot via a cockpit switch. The auxiliary fuel pump placard stated, “Take-off and land with AUX fuel pump off except in case of loss of fuel press.” The airplane’s pilot operating handbook (POH), section IV, Normal Procedures, Before Take-Off, states, “Auxiliary Fuel Pump – CHECK OFF”. The airplane was also equipped with an Insight Instrument engine monitoring system. The data showed that, during the accident flight, the fuel flow increased from 23.4 to 28.7 gph with a peak fuel flow of 30.8 gph, followed by a sudden decrease, with a corresponding drop in CHT and EGT. The Continental Motors service information directive (SID) SID97-3F recommended that the fuel flow setting should be between 23.2 – 24.9 gph. Postaccident examination showed bending and crushing near the roots of both wings. Flight control continuity was established from all primary flight control surfaces to the cockpit controls. There was no evidence of any preaccident mechanicalfailures or malfunctions with the airplane that would have precluded normal operation.