History of Flight
On December 2, 2021, at about 1115 Pacific standard time, an experimental amateur-built Sport Copter Vortex gyroplane, registration N425RD, was substantially damaged in an accident near Lakeport, California. The pilot received fatal injuries. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.
Two witnesses located approximately 2 miles west of the accident site reported seeing the gyroplane in level flight at an altitude similar to nearby telephone poles. They then observed it tumble tail over nose three times before losing sight behind a tree line. The gyroplane was not equipped with an automatic dependent surveillance–broadcast (ADS-B) transponder and was flying too low for radar coverage.
Pilot Information
The pilot had been involved in a previous gyroplane accident in the same area in August 2020. The National Transportation Safety Board (NTSB) determined the probable cause of that accident to be the pilot's distraction and failure to maintain adequate airspeed during a low altitude maneuver, resulting in loss of control and collision with terrain (NTSB report WPR20CA253). Flight logbook records for the pilot were not recovered, but at the time of the earlier accident, the pilot reported 853.8 total hours in single-engine airplanes and 71.3 hours in rotorcraft.
Wreckage and Impact Information
The gyroplane came to rest generally intact on its left side on flat, open terrain covered with tall, heavily vegetated brush near the shoreline of a lake. The fuselage sustained crush and bending damage consistent with impact, and there was no evidence of an inflight structural failure. The smell of fuel was present, and no evidence of a wire or bird strike was found. There were no reports of damaged power lines or power outages in the area.
The rotor head and mast remained attached to the airframe. The main rotor blade hub rotated freely, and the two main rotor blades remained attached to the hub bar and straps, both exhibiting a 20° downward bow outboard of the strap fittings. Both blades showed similar tear marks on their trailing edge skins just outboard of the straps. One blade had a black streak on its lower surface next to the strap, consistent with contact from the engine propeller.
Flight control continuity was established from the foot pedals to the rudder surface and from the cyclic control stick to the rotor mast. No evidence of a catastrophic engine failure was found; the engine crankshaft could be rotated via the propeller reduction drive hub. One propeller blade remained attached at the hub, while the second blade detached at the root, and the third blade similarly detached with its tip not located in the surrounding vegetation. Further examination revealed no preaccident mechanical malfunctions or failures that would have precluded normal operation.
Medical and Pathological Information
An autopsy performed by Bennet Omalu Pathology in Stockton, California, listed the cause of death as blunt force trauma. Toxicology testing by the FAA Forensic Sciences Laboratory found no drugs of abuse.
Additional Information
According to the FAA Rotorcraft Flying Handbook (FAA-H-8083-21), Chapter 21 on Gyroplane Emergencies, if rotor force is rapidly removed, some gyroplanes may tend to pitch forward abruptly, a condition referred to as power pushover, forward tumble, or buntover. The handbook states that a power pushover can occur on gyroplanes with propeller thrust line above the center of gravity and without an adequate horizontal stabilizer. Removing rotor force (unloading the rotor) can occur from excessive pilot-induced oscillations, extreme turbulence, or rapid forward nose movement after a steep climb. Without correction, the nose pitching action can become self-sustaining and irreversible. The handbook also notes that an adequate horizontal stabilizer slows the pitching rate and allows recovery time.
The Pilot's Operating Handbook for the gyroplane, Section 3.10, Emergency Procedures, Flight Control Malfunction, states that an immediate reduction of power (or speed) may be necessary to avoid pitch oscillations or other effects affecting dynamic or static stability.