History of Flight
On August 29, 2022, about 1204 Alaska Daylight Time, an amateur-built Charles Brad Story TT FOX airplane, N2723P, sustained substantial damage when it impacted a hangar at Wolf Lake Airport (4AK6) in Wasilla, Alaska. The pilot, who was the sole occupant, was fatally injured. The airplane was operated by the pilot as a Title 14 Code of Federal Regulations Part 91 test flight. According to family, the purpose of the flight was to complete the required hours during Phase I testing of the experimental aircraft.
Witnesses at the airport observed the airplane depart to the south and then heard it return. The pilot radioed that he was on the downwind leg of the traffic pattern for landing, with no further transmissions. Flight path data from an onboard Dynon Skyview D1000 showed the airplane turned crosswind after takeoff, then entered a right downwind for runway 08. Once abeam the departure end, it stopped climbing, began descending, and turned toward the approach end of the gravel strip, runway 02. Witnesses then saw the airplane flying low and fast toward the gravel strip. They reported hearing engine rpm changes described as revving, going to idle, and surging. Two witnesses noted pitch oscillations. One witness saw the airplane abruptly pitch down as if it hit something, then impact the hangar.
Personnel Information
The pilot was the owner and builder of the airplane. He had completed four test flights in this aircraft starting on August 21: the first and second flights each logged 0.6 hours, and the third and fourth flights were 1 hour each. All flights were conducted at 4AK6.
Aircraft Information
The pilot began building the airplane about three years before the accident and finished a few weeks prior. The FAA DAR-F Inspector completed a Conformity Inspection on August 13, 2022, and a Special Airworthiness Certificate was issued the same day. After passing inspection, the airplane required 25 to 40 hours of test flights in designated non-populated areas to ensure all components operated properly before carrying passengers. At the time of the accident, the airplane had accumulated about 3.2 flight hours during this test phase.
Airport Information
Wolf Lake Airport (4AK6) is a public-use airport in Wasilla, Alaska. The accident occurred in a relatively flat, residential area adjacent to the airport.
Wreckage and Impact Information
The airplane impacted in a nose-low attitude into the back of a hangar and came to rest inside. Evidence of a tree strike was found about 60 to 80 feet before the impact site; the top 10 to 12 feet of the tree was broken off and lying on the ground in the direction of flight. Branches and tree parts were scattered between the tree, the hangar, and inside the hangar.
The main fuselage was on the hangar floor, with the right wing still attached in the attic. The left wing was impact-separated and found outside. The flaperon handle was set to the 10° position. Flight control continuity was established for all controls, with separations due to impact damage.
Examination of the engine revealed compression in both cylinders, clean spark plugs, and engine continuity confirmed by operating the starter pull handle, which moved the propeller. The engine was a Rotax 850, originally designed for snowmachines and not for aircraft use. The airplane had a three-blade composite propeller, all blades showing impact damage. No mechanical malfunctions or anomalies were noted that would have precluded normal operation.
Data from the Dynon Skyview system, downloaded at the NTSB Recorders Laboratory, showed that at 1203, about 8 seconds before impact, engine rpm cycled from idle to maximum three times. Witnesses also reported hearing engine rpm fluctuations just before impact.