N124CF

On March 14, 1999, at 1038 eastern standard time, a homebuilt Rotorway Exec 162F, N124CF, was substantially damaged while the pilot was practicing hovering in an open field in Mechanicsburg, Pennsylvania. The certificated private pilot received minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed for the flight conducted under 14 CFR Part 91.

In an interview, the pilot reported that he was on his first solo flight when the accident occurred. He had brought the helicopter to what he estimated was a 6 inch hover. After a few seconds, the helicopter drifted left and settled. The left rear skid caught on the ground and the helicopter rolled over on its left side. The frame and main rotor drive shaft were bent, and the main rotor blades were destroyed. The landing surface was a flat, hard packed field, about 5 acres in size which had recently been rolled.

According to the pilot, he held a single engine land rating for airplanes, and had logged 69.3 hours in airplanes; however, he had not flown in several years. As the construction of the helicopter neared completion, the pilot went to the kit manufacturer's facility in Arizona, where he received 9.9 hours of dual helicopter instruction in the same model. The pilot had been signed-off for solo flight on January 29, 1999, and had not flown again until the accident flight. The pilot's total flight time, including his recent helicopter dual instruction, was 79.2 hours.

The flight instructor who signed the pilot off for solo flight reported the pilot was "good" and did not remember him as having any specific problems.

According to Federal Aviation Administration Advisory Circular 90-87 HELCIOPTER DYNAMIC ROLLOVER:

"...During normal or slope takeoffs and landings with same degree of bank angle or side drift with one skid/wheel on the ground, the bank angle or side drift can place the helicopter in a situation where it is pivoting (rolling) about a skid/wheel which is still in contact with the ground. When this happens, lateral cyclic control response becomes more sluggish and less effective than for a free hovering helicopter. Consequently, if a roll rate is permitted to develop, a critical bank angle (the angle between the helicopter and the horizon) may be reached where roll cannot be corrected, even with full lateral cyclic, and the helicopter will roll over onto its side. As the roll rate increases, the angle at which recovery is still possible is significantly reduced...."