CEN24LA020

The total loss of engine power due to fuel starvation as a result of the pilot’s improper configuration of the automatic fuel transfer system. Contributing to the accident was the pilot’s failure to adequately monitor the header tank’s fuel quantity.

The pilot reported that before takeoff on the cross-country flight, the airplane contained 100 gallons of fuel, with 11 gallons in the header fuel tank, and the airplane’s automatic fuel transfer system was configured as per the checklist. No anomalies were noted during the engine start, takeoff, and initial climb. About 7 minutes into the flight and climbing through 12,000 ft mean sea level (msl), the engine sustained an abrupt loss of power that was confirmed by the loss of torque and engine compressor turbine rpm (Ng) speed. The pilot noted no cockpit warning or abnormal indications before the loss of engine power. The pilot declared an emergency and then executed a 180° turn back to the departure airport. The pilot attempted two engine restarts, and both were unsuccessful. Unable to make it back to the airport, the pilot executed an off airport forced landing. During the forced landing, the airplane sustained substantial damage to the fuselage and both wings. A postaccident examination of the airframe, fuel system components, and functional engine test revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The fuel transfer pump switch was found in the manual position. The engine’s fuel was provided by the airframe header tank. Avionics data indicated that during the short flight, the header fuel tank quantity consistently decreased, and the airplane’s automatic fuel system did not continually resupply fuel to the header tank. Based on the available data, a functional engine test, and functional testing of the airplane’s fuel system, it is likely the pilot improperly configured the airplane’s fuel transfer system, which prevented the header fuel tank from automatically refilling during the flight and resulted in fuel starvation and total loss of engine power. Although the pilot reported that he had configured the airplane’s automatic fuel transfer system per the checklist, it is likely that the fuel transfer switch was in the manual or OFF position during the flight. In addition, the pilot did not properly monitor the header tank’s fuel quantity.

A review of the airplane’s maintenance records revealed that in 2003 the airplane was modified to a JetProp DLX per a supplemental type certificate, which included the installation of a Pratt and Whitney Canda (PWC) PT6A-35 turboprop engine. The pilot reported that he purchased the airplane in 2014. On August 22, 2023, an airframe logbook entry indicated that a Garmin G500TXi system and other avionics were installed, and an Aspen Avionics primary and multifunction flight display system was removed. According to the pilot, due to delays in available avionics components, the airplane was out of service in maintenance for about 1 year and 4 months. According to the airplane HOBBS indicator, at the time of the accident, the airplane had accumulated about 11 hours of total time since the avionics installation. An autopsy was not performed on the passenger. On October 23, 2023, at 1611 central daylight time, a Piper PA-46-350P airplane, N92884, sustained substantial damage when it was involved in an accident near Pierre, South Dakota. The pilot sustained serious injuries, and the passenger sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, before takeoff from the Pierre Regional Airport (PIR), Pierre, South Dakota, the airplane was fueled with 10 gallons of fuel for a total of 100 gallons on board for the planned flight to Steamboat Springs, Colorado. The pilot reported that before takeoff, the header fuel tank contained 11 gallons of fuel, fuel boost pump No. 1 was selected, the fuel transfer switch was in the AUTO position, and the fuel selector was in the right fuel tank position. No anomalies were noted during the engine start, takeoff, and initial climb. About 11,000 ft mean sea level (msl), air traffic control cleared the pilot to flight level 220. While climbing through 12,000 ft msl, the engine sustained an abrupt loss of power that was confirmed by the loss of torque and engine compressor turbine rpm (Ng) speed. The pilot noted no cockpit warning or abnormal indications before the loss of engine power. The pilot declared an emergency and then executed a 180° turn back to PIR (see Figure 1). Figure 1. Overhead view of the flight track. During the emergency descent, the pilot attempted to restart the engine by switching boost pumps, switching the fuel tank selector, and activating the emergency header tank pump, but the restart was unsuccessful. The pilot declared an emergency and intended to return to PIR. The pilot attempted another engine restart procedure with the fuel at cutoff, boost pump on, igniters at AUTO, generator off, and starter on. At this time, Ng was about 15%, the fuel condition lever was advanced, and a “pop” was heard with a puff of smoke from the right exhaust. The engine torque did not increase, so the pilot closed the fuel condition lever. The pilot reported he did not use the manual override fuel switch during the emergency descent. The pilot also reported that while maneuvering back toward PIR, the airplane also lost electrical power, which resulted in a loss of the primary flight display, both GPS displays, and annunciator panel. The condition resulted in the pilot becoming disorientated in the descent to the airport. He realized he was going to be unable to make PIR and attempted a forced landing to bluffs and rolling terrain (see Figure 2). Figure 2. Airplane as it came to rest in the rolling terrain. The airplane impacted the terrain, came to rest upright, and sustained substantial damage to the fuselage and both wings. After the accident, the pilot observed that the passenger, who was seated in a rear forward-facing seat, was barely conscious. After checking the passenger’s vital signs, the pilot performed cardiopulmonary resuscitation until first responders arrived on scene.  Initial postaccident examination of the airplane at the accident site revealed no preimpact external anomalies or malfunctions, and the airplane was retained for further examination. Examination of the airframe revealed the cockpit battery display indicated 24.7 volts, the fuel selector was in the right tank position, the fuel transfer pump switch was in the manual position, and the emergency fuel transfer switch was off. The header tank contained about 2.4 gallons of fuel consistent with Jet A. The fuel line between the oil/fuel heater and the engine fuel pump was opened and no fuel drained from the fuel line. The airframe fuel filter and bowl contained about 1 pint of fuel that was clear of contaminants. The airframe fuel system, to include the right-wing fuel transfer pump, fuel selector valve, emergency transfer fuel pump, header tank Nos. 1 and 2 boost pumps, header tank float switch, header tank pressure transducer, firewall shutoff valve, and annunciator panel lights were tested, and no anomalies were noted. The fuel lines, from the wings to the engine fuel pump, were clear of obstructions when blown with compressed air. The left-wing fuel transfer pump wiring was damaged during the recovery process, and the pump was removed for further examination. The transfer pump was bench tested at Piper Aircraft, Inc, Vero Beach, Florida, and no anomalies were noted. All four propeller blades were bent aft and found secure in the propeller hub. The blades were in the low pitch position and displayed minor cambered face scratching. Following an airframe examination, the engine was removed from the airframe and shipped to PWC for a functional test. The engine was installed in the test cell and serviced with oil. The engine was functionally tested, which included a dry motoring check, engine start, engine warm up at ground idle setting, normal acceleration, normal deceleration, and shut down. A second engine start was done to perform engine handling tests, slam acceleration, and slam deceleration checks. According to PWC, during both engine functional test runs, the engine performance and behavior was within specifications with no limits exceeded. The Garmin G500 TXi system primary flight display was removed and sent to the National Transportation Safety Board’s Recorders Laboratory for data extraction. According to the data, about 7 minutes after takeoff, the engine sustained a loss of fuel flow, engine torque, and Ng, consistent with the reported loss of engine power. Before takeoff, the header fuel tank quantity indicated 10.8 gallons, and during the flight, the header tank fuel quantity continually decreased to 5.7 gallons until the engine power loss. About 1 minute after the power loss, the header fuel tank quantity began to increase, and about 4 minutes later, the header tank fuel quantity reached 11.1 gallons and remained at that quantity until the accident impact. The following are excerpts and procedures from the JetProp DLX Pilot’s Operating Handbook and Federal Aviation Administration Approved Airplane Flight Manual: Section 3 Emergency Procedures Engine Power Loss in Flight – Engine Flame Out A flameout will be noticed by a drop in InterTurbine temperature (ITT), torquemeter pressure, and Ng. The engine may be restarted in the manner described under Air Starts. Air Start The best air start technique is to initiate the re-light procedure immediately after a flameout occurs, provided the pilot is certain that the flameout was not the result of some malfunction which might make it dangerous to attempt a re-light. If Ng drops below 50%, ignition switch off and proceed with normal air start procedures. Figure 3. Jet Prop DLX air start procedures. Manual Override Operation The manual override switch should only be used to modulate engine power to allow the pilot to continue flight to the nearest airport should one of the following conditions occur: (a) Uncommanded engine power roll back to idle and unable to recover with the Power Control lever. (b) No response to the Power Control lever when st