20210824014719A

On August 24, 2021, at approximately 1926 eastern daylight time (2326 UTC), a just highlander, N101KL, was substantially damaged from an off field landing accident while landing at a Private landing strip near Crittenden, Kentucky. The personal flight was operating under title 14 CFR part 91. Visual meteorolgical conditions prevailed at the time of the accident. The cincinnati/northern Kentucky airport METAR reported at 2252 uct, winds 220 degrees at 5 knots.

The pilot took off from his Private field at 6:45 pm and performed two touch and go landings at the gene snyder airport(K62), falmouth, Kentucky before returning to his Private field on a ten minute flight. On the return leg from K62, he stated he observed fuel in both fuel tank site tubes. He estimated there was over an hour of fuel reseve based on his departure calculation and expected fuel burn.

The pilot?s Private landing strip has two turf runways. The first runway was oriented 030° and about 940 ft long. The second runway bent sharply to the left, was oriented 330° and about 725 ft long. The pilot stated he planned to land on the field oriented on the 030º heading. At 300? On final approach to the 030º heading runway, he decided to perform a go around and land on the south strip which is orientated on a 210º heading. The pilot stated he applied full power and was climbing to set up for left downwind for the south bound landing. He was about to cross-mid field when the engine completely stopped. The pilot performed a forced landing. The airplane crossed a road and came to rest upright with the right main landing gear separated, and substantial damage to the wings and empennage.

This inspector examined the aircraft?s fuel system. No fuel was found in the engine?s twin carburator bowls giving an indication of a possible fuel interruption. There was approximately 1.5 gallons of fuel drained from the aircraft post accident. The POH does not mention or have warnings of possible fuel interuption due to unusable fuel remaining. The fuel sight tubes do not show fuel quanity graduation markings to indicate the fuel remaining based on the amount of fuel filling the tube. The pilot is require to do a rough estimate of fuel remaining based on the amount of fuel showing in the tubes.

The following field test was performed on 09/09/2021 to determine usable vs un-usable fuel in each wing tank.

The aircraft was placed on level ground in a hangar. Both wing tanks were emptied via the fuel drain sump. A sling was placed around the empennage of the aircraft and attached to the front end loader of a farm tractor. The fuel lines running from both wing fuel tanks were detached at the header tank, and the ends placed in a bucket. The aircraft was then put in different pitch and roll situations, using the aircrafts EFIS as reference, which mimicked the data downloaded from the aircrafts EFIS during its final flight. Water was then measured and added to both wing tanks until it flowed into the bucket to determine the amount of un-usable fuel with the following results:

With the aircraft at 0° pitch and roll, 1.75 gallons of water was added to each tank before flow was noted into the bucket from both tanks. With the aircraft placed at -12.5° pitch (nose down) and remaining at 0° roll, 6 gallons of water was added to each tank before flow into the bucket was noted. With the aircraft remaining at -12.5° pitch and a left roll of 8° applied, the right tank took 3.5 gallons of water and the left tank 6.5 gallons of water before flow into the bucket was noted. Only 1.5 gallons of fuel was drained after the accident, putting remaining fuel well below useable amounts.

Each fuel tank holds 13 gallons of fuel. The header holds 40 ounces (.31 gallons). There is no secondary pickup in the fuel tanks due to the folding wing design of the aircraft.