20070227002149A

(-23) Sequence: the accident aircraft, CE-182-H, N1864X departed henderson executive airport (hnd) and flew to the dry lake area south of Jean, NV to practice airwork. The pilot then proceeded northbound so as to arrive in the traffic pattern at Jean Airport, NV (0L7), for a right downwind rwy 20R. Winds at 0L7 had been reported from 180 to 15 knots. N1864X was number two behind a mercy air bell-222 helicopter (N403MA) already in sequence to land on 20R. N403MA advised on CTAF that he would change to rwy 20L in order to accommodate the arrival of N1864X. N403MA continued the approach ro rwy 20R, then broke-off sse and approached the threshold of rwy 20L. The helicopter hovered momentarily, and landed on the approach end of rwy 20L facing south. At approximately 50 to 100 feet on the approach to 20R behind the helicopter, N1864X experienced an uncommanded roll to the left that the pilot could not counter with opposing control inputs. The aircraft's left wing contacted the ground approximately 60 feet left of the 20R runway threshold edge. At approximately 110 feet from the threshold edge, the aircraft nosed into the sand with a force sufficient to break off the nose gear and propeller, deform the cockpit, cockpit floor, and instrument panel, and disintegrate the plexiglas windshield. Marks in the sand at this point, and damage to the propeller are consistent with an engine producing greater than idle power. The propeller and nose gear came to rest approximately 150 feet and 170 feet respectively from the threshold edge, on the same energy line approximately 75 degrees to the runway centerline. After making contact on the nose, the aircraft rebounded and rolled right so as to cause the outboard half of the right wing leading edge to make heavy contact with the ground. At this point the passenger side door separated from the aircraft. The aircraft then upended, coming to rest on the nose at a 60 degree angle approximately 205 feet to the left of rwy 20R. Damage: the aircraft was damaged beyond repair. The left wing tip fairing and navigation light were destroyed. The left wingtip structure was deflected up from the norm at a 30 degree angle, starting approximately five feet from the tip. The inboard end of the left aileron was deformed. The outboard 60 percent of the right wing leading edge was crushed and the entire wing panel deflected up 15 degrees at the point where the strut attached to the spar. The inboard end of the right aileron was deformed. The dorsal and side skins of the aft fuselage were deformed showing evidence of significant torsion loads, likely the result of the impact on the nose. The propeller and spinner had separated from the engine as a unit. The propeller blades were scored and curled aft. The nose landing gear strut had separated at the mounting trunnion. Most of the nose gear fairing was still attached and intact. The cockpit, cockpit floor and instrument panel were deformed, having pulled away from the airframe with the firewall and engine. The windshield was destroyed. The left main tire/wheel assembly was bent outward 30 degrees where it attached to the spring steel strut. Controls: investigators were unable to establish control continuity to any control surface due to the destruction of the primary control connections at the firewall. In the cockpit the following positions and indications were noted: fuel selector - both, props - full fwd, primer - in/locked, cowl flaps - closed, mixture - rich, carb heat - off, flaps - 10 degrees, parking brake - off, throttle - low power, magnetos - both, altimeter - 2460' (29.92). Injuries: the pilot in command suffered a laceration and minor injuries to his shoulders. Findings: there was no post crash fire. There was no evidence of fuel starvation, fuel exhaustion, or engine failure. The physical evidence, together with pilot and witness statements leads to loss of control as the cause of the accident. A contributing factor was significant wake turbulence caused by the rotor wash from the mercy air bell 212 helicopter. The rotor wash had migrated downwind into the 20R approach end environment, contributing to the upset of the accident aircraft.