Amateur-built LANCAIR 4P accident near Hartford, Connecticut, January 28, 2023

The NTSB's narrative final · quoted from the NTSB record

The pilot of the turbine-powered, experimental amateur-built airplane had ongoing issues with fuel migrating from the right wing fuel tank to the left wing tank when the airplane sat in the hangar for several days or more. Multiple witnesses at the airport on the day of the accident observed the airplane sitting with its left-wing low while parked in the hangar and on the ramp; however, the pilot did not notice the leaning during his preflight inspection nor did he visually check the fuel tanks before flight. The pilot recalled that before takeoff both fuel gauges indicated 38 gallons of fuel was present in each fuel tank. The pilot taxied for takeoff and performed a rejected takeoff due to “something not feeling right” with the airplane. The pilot returned to the ramp environment and taxied around briefly, before deciding to return to the runway for another takeoff attempt. During the second takeoff, at rotation, the airplane briefly climbed but immediately began a roll and turn to the left. The pilot attempted to correct the left roll by applying right roll with the flight controls and by reducing engine power; however, the left roll and turn continued. The airplane impacted terrain in a left turn with the left wing impacting the ground first. Subsequently, the airplane cartwheeled and an explosion and postcrash fire immediately ensued. The pilot was ejected from the airframe during the impact and was rescued by first responders. Data recovered from the primary flight display (PFD) found that the last indicated fuel quantity recorded, during the second taxi for departure, was 82 gallons in the left tank and 39 gallons in the right tank, resulting in an imbalance of 43 gallons. During initial flight testing of the accident airplane make and model, it was found to have a lack of roll control with an imbalance of fuel of 30 gallons below 100 knots airspeed. The accident flight’s takeoff was likely initiated with an imbalance of nearly 43 gallons of fuel, and once the airplane lifted off around 65 knots, the airplane likely lacked the roll authority to stop the left rolling tendencies due to the imbalance. The most recent fuel system maintenance work involved the replacement of an on/off cross-feed valve. The valve was found in the wreckage mostly closed and it had seized; however, it displayed a slight angle towards the open position. It is likely that the slight opening allowed for fuel to migrate from the right wing to the left wing over the course of the 30 days the airplane sat between flights. The pilot had multiple opportunities to notice the fuel imbalance. He could have checked the fuel filler caps during preflight or observed that the PFD displayed a significant fuel imbalance. Furthermore, two witnesses at the airport observed that the airplane was leaning to the left before flight. Given the airplane’s history with a fuel imbalance, the pilot should have checked the airplane’s overall disposition during preflight inspection. Lastly, he performed a rejected takeoff due to something not feeling right with the airplane, but performed no meaningful troubleshooting nor did he exit the airplane before deciding to take off again. Had the pilot ended the flight after the rejected takeoff and checked the fuel, or called for maintenance to examine the airplane, the fuel imbalance likely could have been discovered. Further exacerbating rolling tendency was a gusting crosswind from the airplane’s right side, which likely added to the left rolling tendency the pilot experienced.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.