CEN18LA047

The pilot's inadequate preflight planning and his decision to depart without the required fuel reserve, which resulted in fuel exhaustion during a night approach and subsequent loss of engine power.

The private pilot departed on a cross-country flight in his high-performance, turbine-powered airplane with full tanks of fuel. He landed and had the airplane serviced with 150 gallons of fuel. He subsequently departed on the return flight. As the airplane approached the destination airport, the pilot asked for priority handling and reported that the airplane "lost a transfer pump and had a little less fuel than he thought," and he did not want to come in with a single engine. When asked if he needed assistance, he replied "negative." The pilot was cleared to perform a visual approach to runway 19 during night conditions. As the airplane approached the airport, the pilot requested the runway lights for runway 25 be turned on and reported that the airplane lost engine power in one engine. The controller advised that the lights on runway 25 were being turned on and issued a landing clearance. The airplane impacted terrain before the threshold for runway 25. During examination of the recovered wreckage, flight control continuity was established. No useable amount of fuel was found in any of the airplane's fuel tanks; however, fuel was observed in the fuel lines. All transfer pumps and boost pumps were operational. The engine-driven fuel pumps on both engines contained fuel in their respective fuel filter bowls. Both pumps were able to rotate when their input shafts were manipulated by hand. Disassembly of both pumps revealed that their inlet filters were free of obstructions. Bearing surfaces in both pumps exhibited pitting consistent with pump operation with inadequate fuel lubrication and fuel not reaching the pump. The examination revealed no evidence of airframe or engine preimpact malfunctions or failures that would have precluded normal operation of the airplane. Performance calculations using a flight planning method described in the airplane flight manual indicated that the airplane could have made the return flight with about 18 gallons (119 lbs) of fuel remaining. However, performance calculations using a fuel burn simulation method developed from the fuel burn and data from the airplane flight manual indicated that the airplane would have run out of fuel on approach. Regulations require that a flight depart with enough fuel to fly to the first point of intended landing and, assuming normal cruising speed, at night, to fly after that for at least 45 minutes. The calculated 45-minute night reserves required about 56 gallons (366 lbs) of fuel using a maximum recommended cruise power setting or about 37.8 gallons (246 lbs) of fuel using a maximum range power setting. Regardless of the flight planning method he could have used, the pilot did not depart on the accident flight with the required fuel reserves and exhausted all useable fuel while on approach to the destination.

A National Transportation Safety Board (NTSB) senior meteorologist collected weather data and produced a Weather Study. The study is appended to the docket material associated with this investigation. The 46-year-old pilot held an FAA private pilot certificate with airplane single and multi-engine land and instrument ratings. He also held an FAA third class airman medical certificate, dated May 17, 2017. According to information from the FAA, the pilot reported that he had accumulated 2,500 hours of total flight time. The pilot's experience was requested from a point of contact for the pilot and a King Air C90 Recurrent Training Course certificate, dated October 25, 2017, was provided. An RFD deputy director, in part, reported that from first responders and his knowledge of the scene, there was never any visible fuel exiting the aircraft while it was sitting on the ground or while it was being lifted and moved. No pooled fuel was observed. However, there was a slight fuel smell around the airplane. The wreckage was recovered to a hangar at RFD and the airframe and engine were subsequently examined by air safety investigators from the airplane and engine manufacturers, FAA inspectors, and the NTSB investigator in charge. The empennage was found separated from the fuselage aft of the rear pressure bulkhead. The ends of a rudder trim cable exhibited a separation consistent with overload and the rudder torque tube was found separated from its bellcrank. Flight control continuity was established. Both the left and right transfer pump switches were found in the OFF position. The airplane's battery was reconnected. Both the left and right transfer pumps and the right boost pump were operational using the airplane's wiring. However, a wire going to the left boost pump was found separated in an area of structural damage. The left boost pump was operational when battery power was applied directly to that pump's wiring. No useable amount of fuel was found in any of the airplane fuel tanks. However, a liquid consistent with fuel was observed in fuel lines. All engine cable control continuity was established to the left engine and right engine power and condition control cable continuity was established. The right engine's propeller control was bound when it was manipulated by hand. None of the propeller blades exhibited any leading-edge damage and both spinners did not exhibit any rotational witness marks. The first stage blades in both engines' compressor section were manipulated by hand and continuity was established to their respective accessory gearboxes. Some of the left engine power turbine blades exhibited fracture witness marks. Observation of the right engines power turbine blades revealed that they were intact. The engine driven fuel pumps on both engines were removed. Liquid consistent with fuel was found in both engines' fuel filter bowls. However, both their bowl fuel filters were discolored. Both pumps were able to rotate when their input shafts were manipulated by hand. Disassembly of both pumps revealed that their inlet filters were free of obstructions. Bearing surfaces in both pumps exhibited pitting consistent with pump operation with inadequate fuel lubrication. No airframe or engine preimpact anomalies were found that would have prevented normal operation of the airplane. The Stratus unit was recovered from the cockpit and was shipped to the NTSB Vehicle Recorder Laboratory. N500KR, a 1977 model Beech C90A King Air, was an all-metal, pressurized, low-wing, retractable landing gear, twin-engine airplane with serial number LJ-708. According to the airplane flight manual (AFM), the airplane could operate at altitudes up to 30,000 ft. The airplane was equipped with two Pratt & Whitney Canada (PWC) turbo propeller PT6A-21 engines each rated at 550 horsepower, each driving their own McCauley 4-blade, constant speed, fully reversing, aluminum alloy propeller. The left-hand engine had serial number 24390 and the right-hand engine had serial number 24387. An airplane maintenance record endorsement dated August 25, 2017, showed that the airplane was inspected in accordance with a phase 3 and 4 inspection program and that the airplane had accumulated 9,856.7 hours of total time. The PT6A-21 engines have three-stage axial and single stage centrifugal compressors, driven by single stage reaction turbines. The power turbine, another single stage reaction turbine, drives the propeller shaft. Both the compressor turbine and the power turbine are located in the approximate center of the engine with their shafts extending in opposite directions. The accessory drive at the aft end of the engine provides power to drive the fuel pump, fuel control unit, oil pump, starter-generator, and tachometer. The engine fuel system consists of an engine-driven fuel pump, a fuel control unit, a flow divider, inlet manifold, thirteen manifolds nozzles, and two fuel drain valves. The fuel pump fuel control unit assembly is mounted on the engine accessory case and is shaft-driven at a speed proportional to that of the compressor turbine. The fuel system consists of two separate systems connected by a crossfeed system. Fuel for each engine is supplied from a nacelle tank and four interconnected wing tanks for a total of 192 gallons of usable fuel for each side with all tanks full. The outboard wing tanks supply the center section wing tank by gravity flow. The nacelle tank draws its fuel supply from the center section tank. Since the center section tank is lower than the other wing tanks and the nacelle tank, the fuel is transferred to the nacelle tank by the fuel transfer pump in the low spot of the center section tank. Each system has two filler openings, one in the nacelle tank and one in the leading-edge tank. Servicing the nacelle tank first, then the wing tanks, assures that the system is properly filled. A crossfeed valve in the left-hand fuel system connects the two systems when the crossfeed valve is OPEN. Each system has a submerged boost pump in the nacelle tank that supplies the motive force to transfer fuel as well as fuel boost to one or both engines. With one engine inoperative, the crossfeed system allows fuel from the inoperative side to be supplied to the operating engine. The fuel system is vented through a recessed ram scoop vent that is coupled to an external vent, located on the underside of the wing, adjacent to the nacelle. The external vent is heated to prevent icing. One vent acts as a back-up for the other should one or the other become blocked. The boost pumps are submerged, rotary, vane-type impeller pumps, electrically driven. One pump is located in each nacelle tank. Fuel transfer is accomplished when the TRANSFER PUMP switches are turned ON, unless the nacelle tanks are full. A TRANSFER TEST switch (placarded L and R) is provided to verify the operation of each pump when its nacelle tank is full. The nacelle tanks will continue to fill until the fuel reaches the upper transfer limit and a float switch turns the pump off. As the engines burns fuel from the nacelle tanks (60-gallon capacity each tank), fuel from the wing tanks transfers into the nacelle tanks when their level drops approximately 10 gallons. When 131 gallons of fuel (each side) are used from the wing tanks (132 gallons usable each side), a pressure sensing switch reacts to a pressure drop in the fuel transfer line. After 30 seconds. the transfer pump shuts off and the annunciator panel illuminates, showing a NO FUEL TRANSFER light. The NO FUEL TRANSFER light also functions as an operation indicator for the transfer pump. Extinguishing the NO FUEL TRANSFER light is accomplished by turning the transfer switch OFF. If the transfer pump fails to operate during flight, gravity feed will perform the transfer. When the nacelle tank level drops to approximately 150 lbs, the gravity feed port in the nacelle tank opens and gravity flow from the wing