The experimental-certified 1981 Bell 206B that crashed April 16 in Arizona was performing autorotations at maximum gross weight while fitted with developmental Van Horn Aviation main rotor blades, according to the preliminary NTSB report issued late last week. That accident killed the helicopter’s two occupants—contract test pilot Rucie Moore and Van Horn engineering manager Stephen Estes.
According to the NTSB, a witness one-third of a mile from the crash site heard a loud bang and then saw the helicopter and “several other objects” descending toward the ground. “Initial examination of the main wreckage revealed post-crash fire and impact damage consistent with a right-side-down, nose-level attitude during ground impact. The main rotor hub assembly, vertical tail, tail rotor assembly, tail rotor driveshaft, and forward induction cowl fairing separated from the main wreckage and was found in the debris field. The debris field was about one mile long and 1,000 feet wide, covering an area of wooded desert terrain and flood irrigated alfalfa fields,” the NTSB said.
The helicopter was on the second of two planned test flights that initially departed Mesa’s Falcon Field (FFZ) at 5:45 a.m. local time. Between flights, at 6:20 a.m., approximately 100 pounds of ballast was added to the helicopter, which then again departed Falcon at 6:32 a.m. The crash occurred at 7:06 a.m. Reported weather at FFZ at the time of the accident was wind from 130 degrees at five knots, visibility 10 miles, and clear skies.
These test flights consisted of multiple autorotations at maximum gross weight with simulated loss of engine power. The accident occurred during the last scheduled test flight before the certification process, the NTSB said.