Accident Details
On June 5, 2020, at approximately 1925 eastern daylight time, an experimental, amateur-built Challenger II airplane, registered as N850RW, was substantially damaged in an accident near Wurtsboro-Sullivan County Airport (N82), Wurtsboro, New York. The pilot and a student pilot aboard were fatally injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a test flight.
Witness Account
According to a witness, the airplane appeared tail-heavy before departure. The pilot and student pilot added ballast to the front of the airplane and performed several high-speed taxi runs prior to taking off for the test flight. After liftoff, the airplane began to yaw to the left and continued in a left yaw toward a ridgeline. The airplane did not climb and remained just above the treetops. The witness reported hearing the pilot reduce power shortly before losing sight of the airplane over the trees and then hearing the impact.
Site and Airplane Examination
An inspection by a Federal Aviation Administration (FAA) inspector revealed that the airplane descended nose-first into the trees, came to rest mostly intact and inverted in a wooded area approximately 1,420 feet and 143° from the center of the airport. The debris field was limited to the size of the airplane. Both wings were substantially damaged; the right wing was mostly separated at the wing root due to impact forces. The empennage remained largely undamaged. A faint odor of fuel was present at the accident site.
After recovery, the engine and accessories were examined under FAA supervision. Both cylinder carburetor float bowls and the primer bulb in the fuel line contained fuel free of water and debris. All spark plug leads were securely attached except for the aft spark plug in cylinder No. 2, which was damaged by impact. The spark plugs showed no anomalies when removed. The propeller could be rotated by hand, and thumb compression and suction were noted on both cylinders. No engine anomalies were identified. One propeller blade was fractured about 8 inches from the hub and had leading edge damage near the tip; no chordwise scratching was present on either blade.
Control continuity was established through the rudder cables, but the rudder pedals were not movable. Three canvas bags of sand ballast were found in the forward section: one on each side of the rudder pedals and one forward of the pedals on the tube bracing the nose wheel. The right-side bag had a small tear and contained 18 pounds of sand, with small amounts of sand nearby. The left-side bag was wrapped around the bottom of the left rudder pedal, significantly torn, and weighed 5 pounds, with a small amount of sand nearby. The center bag was mostly intact and weighed 22 pounds. The inspector opined that all bags were likely of equal weight before the flight.
Weight and Balance Considerations
According to FAA records, the two-seat airplane was issued a Special Airworthiness Certificate on November 22, 2019. It was powered by a rear-facing Rotax 503ULDCDI, two-cylinder, 50-horsepower engine mounted aft of the wings behind the main cabin, driving a Warp Drive two-bladed propeller. Logbook examination showed that the airplane had not completed the required 40 hours of Phase I flight testing.
Weight and balance calculations were performed using the aircraft's weight and balance documents, an estimated fuel load of 5 gallons (half a tank), the pilot's most recent FAA physical weight, the student pilot's autopsy weight, and 66 pounds of ballast. The calculated takeoff weight was about 927 pounds, with a center of gravity 82.86 inches aft of datum. The manufacturer's specifications listed a maximum allowable gross takeoff weight of 800 pounds and a center of gravity range at takeoff of 80 to 90 inches aft of datum.
The Quad City Ultralight Aircraft Corp. "Challenger Owner's Manual" stated that if the nose wheel does not remain in contact with the ground, ballast must be added. Solo flight was restricted to the front seat, and for two-seat models with the heavier 503 engine, electric start, and 10-gallon fuel tank, ballast might need to be added for pilots under 160 pounds.