ERA21LA338

The personal flight was approaching a private turf runway for landing. After the airplane completed a continuous 260° left-turning approach toward the runway, the pilot decided that he wanted to land to the south rather than to the north and applied engine power. However, the engine lost total power, and the pilot landed the airplane “abruptly” before it impacted a building. The airplane sustained substantial damage to the right wing and empennage. The pilot reported that the left-wing fuel tank was leaking after the accident. The pilot also reported that, at the time of the accident, the airplane had flown a total of about 4 hours since it was last refueled to capacity (26 gallons total). The pilot stated that his planned fuel consumption rate was 5 gallons per hour. Postaccident examination of the airplane found that the left-wing tank contained no fuel and that the right-wing tank contained about 1.5 to 2.0 gallons. A test run of the engine revealed no mechanical malfunctions or anomalies that would have precluded normal operation. A field test was then performed in which the airplane was suspended from a sling, and the pitch and roll attitude captured by avionics data during the continuous left turn just before the accident was applied to the airplane. Water was added to each of the wing fuel tanks to determine the quantity needed to reach the fuel pickup (which unports fuel) on the inboard side of each tank. The test indicated that, when the airplane was in a descending left-turn attitude, fuel began to flow from the right tank at a quantity of about 3.5 gallons; however, about 6.5 gallons had to be added to the left tank before fuel flow was noted. The total amount of fuel onboard the airplane at the time of the accident and its distribution could not be determined based on the available evidence for this accident investigation. However, given the pilot’s estimated fuel consumption rate and the time since refueling, the airplane likely consumed about 20 gallons of fuel, leaving about 6 gallons divided between the two wing tanks. Postaccident testing showed that it is likely that this amount of fuel could have caused fuel unporting from the tank pickups during the extended left turn, resulting in fuel starvation and a total loss of engine power.

On August 24, 2021, about 1926 eastern daylight time, an experimental amateur-built Just Highlander, N101KL, was involved in an accident near Crittenden, Kentucky. The private pilot and the passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, who was also the owner of the airplane, the accident occurred at the end of a 45-minute “sightseeing” flight. The airplane departed from the pilot’s farm and flew to Gene Snyder Airport (K62), Falmouth, Kentucky, where the pilot performed two touch-and-go landings and then established the airplane on a northwest heading for the return flight. While the airplane was in cruise flight, the pilot confirmed that fuel was visible in the “site tubes” of each wing tank and estimated that the airplane had “over an hour of fuel reserves.” The pilot stated that the airplane was established on the left base leg for a landing on a turf runway oriented to the northeast on a heading of 030°. When the airplane was at an altitude of 300 ft above ground level (agl), he decided to land on the same field but to the south. (A satellite image of the pilot’s property revealed two turf runways bisected by a paved road. When looking north, the second turf runway formed a dogleg to the left after the road and was oriented to the north on a heading of about 345°.) The pilot added “full power” and initiated a climb, but the engine lost total power. The pilot then initiated a left bank to use the remaining field beneath the airplane, but he would not have been able to finish the turn, avoid a building, and complete the landing; as a result, the pilot landed the airplane “abruptly” to the left of the building. The airplane came to rest upright with the right main landing gear separated and substantial damage to the right wing and empennage. The pilot reported that the left-wing fuel tank was leaking after the accident. Data downloaded from the airplane’s avionics depicted the airplane crossing over the paved road that bisected two turf runways at an airspeed of 35 knots, on a 290° heading, and an altitude of about 800 ft agl. The airplane entered a left descending 260° turn, aligned with the northeast-oriented runway, and flew its full length (940 ft). The airplane was at an altitude of 100 ft agl, an airspeed of 35 knots, and an engine speed of 1,024 rpm when it overflew the departure end and the extended centerline at the approach end of the north-oriented runway. Five seconds later, the airplane was 215 ft to the right of the north-oriented runway centerline at an altitude of 75 ft agl, an airspeed of 43 knots, and an engine speed of 0 rpm. The airplane’s track arced back toward the north-oriented runway and crossed it on a 320° heading. The final two targets depicted the airplane bisecting the runway on the ground traveling at 35 knots, after which the data ended. Fuel fed from the wing tanks to a small header tank (about 0.3 gallons) andthen to the electric fuel boost pump; the gascolator; the engine-driven fuel pump; and the “splitter,” which supplied fuel to the two carburetors. The pilot reported that he serviced the airplane with 93-octane automotive gasoline and that the engine manufacturer’s estimated rate of fuel consumption was 4.5 gallons per hour; the pilot usually planned for 5 gallons per hour. The pilot stated that, at the time of the accident, he had flown the airplane for about 4 hours since its most recent refueling (2 days before the accident), during which the airplane was fueled with 26 gallons (the total fuel capacity). The pilot also stated that he did not turn on the electric boost pump during the flight, which was his normal practice. Postaccident examination of the airplane revealed that the left-wing tank was empty and that 1.5 to 2.0 gallons of fuel was drained from the right-wing tank. The gascolator was full of fuel, and fuel was present in the inlet line to the engine-driven fuel pump. No fuel was observed in the outlet line of the pump or in either carburetor bowl. The carburetors were reassembled, the fuel lines were resecured, and the fuel system was primed with the electric boost pump. Afterward, an engine start was attempted with the airplane’s battery. The engine started immediately, accelerated smoothly, and ran continuously without interruption until it was stopped with the engine controls in the cockpit. A field test was conducted during which the Federal Aviation Administration inspector assigned to this case returned to the accident site and, with the pilot/owner’s assistance, suspended the airplane by a sling. The purpose of the field test, which was performed in a static environment, was to determine usable versus unusable fuel in each wing tank at pitch and roll attitudes (using the airplane’s electronic flight instrument system) that reflected those in the downloaded data from the accident flight. The results of the testing were intended to demonstrate the fuel quantities at which the main fuel pickups could unport and fuel flow to the 0.3 gallon header tank would be interrupted. Each 13-gallon main fuel tank was equipped with one fuel pickup; neither had a secondary pickup due to the airplane’s folding-wing design. The inspector disconnected the main fuel lines, added water to the fuel tanks, and noted the quantity at which water would flow from the lines. When the airplane’s extended left turn before landing was simulated with a 12.5° nose-down pitch attitude and an 8° left roll, water flowed from the right fuel tank at a quantity of 3.5 gallons. Water did not flow from the left fuel tank until it contained 6.5 gallons. The pilot reported that the fuel pickup in each wing tank was located on the inboard part of the tank and that, given the continuous left turn before landing, the fuel “might have unported.”