Rockwell 700 N700AK

The pilot reported that after about a 2-hour cross-country flight, the right engine fuel boost pump light illuminated during the final approach to the destination airport. The engine sputtered, began to lose power, and the fuel flow fluctuated between 0 to 75 pounds per hour (pph). Once the airplane reached the runway, the engine lost power completely. The pilot said he applied full left rudder to compensate for the asymmetrical thrust, but it became ineffective (likely due to the airplane’s slowing speed during the landing approach). The airplane made a hard right turn even after he reduced power to the left engine, then struck a taxiway and runway light. The pilot reported that after the airplane left the grass infield, it became airborne again. The airplane subsequently stalled and collided with two hangars, resulting in substantial damage to both wings and the fuselage. There was no postimpact fire. The pilot, numerous witnesses, and first responders to the scene reported that there was no fuel spill or smell of fuel. Examination of the airplane revealed the fuel lines to each fuel tank were impact separated from each wing and both tanks were empty of fuel. The fuel caps were secure and their respective flapper seals functioned properly. There was no evidence of a fuel leak or fuel staining anywhere on the airplane. The engine-driven fuel pumps were removed from the right and left engines and less than a drop of fuel was observed in each. The right engine was examined and no mechanical deficiencies or malfunctions were observed that would have precluded normal operation. The fuel boost pump annunciator light is activated by a pressure switch downstream of the pump. If there is no fuel pressure, the light will illuminate. The pilot reported to the National Transportation Safety Board (NTSB) that the fuel on board the airplane at the last takeoff was 87 gallons. Fuel receipts showed that the pilot purchased about 98 gallons of fuel on the day of the accident. Later, the pilot reported that he filled both of the airplane’s wing fuel tanks to about 1 and 1/2 inches below the top of the tanks for a total of 166 gallons (83 gallons per side). However, the pilot had recently purchased the airplane and had only flown the airplane 9 times for a total flight time of 14.6 hours in the last 11 months, including the accident flight. Due to his limited experience in the accident airplane, it is possible that the pilot may have overestimated how much fuel was in the tanks. The airplane was equipped with an engine data monitor that recorded engine data for the entire flight from engine start to the time of the accident. The engine monitor indicated that the right engine was operating for about 2 hours 3 minutes and the left engine was operating for about 2 hours 4 minutes. The data for right engine showed the exhaust gas temperatures (EGT) dropping from between 1,300° to 1,400°F to about 250°F when the monitor stopped recording. The data for left engine shows the EGTs dropping from between 1,300° to 1,400°F to about 1,200° momentarily, and then less than 600°F when the monitor stopped recording. Although the drop of left engine EGTs could have been due to the pilot’s reduction of power to the left engine, the lack of any fuel in the left fuel tank with no reported fuel spill or leaks indicated that it likely sustained a complete loss of engine power soon after the right engine lost power and before the impact with the hangars. During postaccident interviews, the pilot provided varying fuel consumption numbers for fuel planning. He reported that the normal fuel flow for the airplane was 160 – 170 pph (26.6 – 28.3 gph). However, he also stated that the normal fuel flow for cruise setting was 120 - 130 pph (20 – 21.6 gph); fuel flow at full power was 170 pph (28.3 gph). Apart from the fuel flow estimates, the pilot did not provide any additional flight planning information. According to the airplane’s Pilot’s Operating Handbook (POH), a fuel flow of 160 pph during cruise flight equates to a cruise power setting of 55% power at 2,200 rpm. If the airplane was flown at that power setting during cruise flight, the airplane used about 70 gallons of fuel during the flight. Had the pilot used a 75% cruise power setting (75% power at 2,400 rpm), the fuel flow would have been about 256 pph, which would increase the fuel used during the flight to about 100 gallons. No fuel was observed on the airplane after the accident occurred and there was no evidence of any fuel spill or fuel smell. Although the pilot fueled the airplane with about 98 gallons of fuel, given the lack of fuel found at the accident site the pilot likely overestimated how much total fuel was on board the airplane at departure, which led to fuel exhaustion on the final approach. During the flare and touchdown, the pilot then failed to maintain control of the airplane and it veered off the runway, became airborne again, and stalled before it impacted the two hangars.

Quoted verbatim from the NTSB record.