Amateur-built DOMINATOR N85KY accident near Valkaria, Florida

Probable cause

The pilot’s failure to maintain adequate power and airspeed, which resulted in a loss of control, abrupt descent, and impact with terrain. Contributing to the accident was the pilot’s failure to obtain adequate experience in the gyroplane before making the flight.

NTSB analysis

The pilot purchased the single-seat gyroplane and then took flying lessons in a gyroplane with a tandem-seating configuration. The pilot recorded about 7.8 hours in two-seat gyroplanes and had no experience in single-seat gyroplanes. On the day of the accident flight, the pilot was anxious to fly the gyroplane before traveling to the northeast for the summer. During his first flight in the single-seat gyroplane, the pilot had just crossed the approach end of runway 14 when the gyroplane pitched down 30 degrees, then pitched up 45 degrees, and subsequently descended to the ground. Witnesses, who were personal friends of the accident pilot, noted that, in their opinion, the pilot was not experienced enough to fly his gyroplane solo. One witness also stated that he was going to test fly the gyroplane for the owner2 days before the accident flight but was unable due to inclement weather . According to the inventor of the gyroplane, and based on his analysis of the accident flight details, the engine power was reduced with the control stick positioned slightly aft of center and that it appeared that the pilot decreased power and airspeed just before entering a vertical descent to the ground.

Toxicological testing revealed therapeutic levels of diphenhydramine (for example, Benadryl) in the pilot's blood samples. Diphenhydramine is a sedating antihistamine that could impair a pilot's cognitive and psychomotor performance. The diphenhydramine in cavity blood (0.038 ug/ml) was slightly above the lower limit of the normal therapeutic range (0.0250 to 0.1120 ug/ml). Diphenhydramine undergoes significant postmortem redistribution; as a result, it is likely that the pilot's diphenhydramine level was most likely at or below the lower therapeutic level about the time of the accident. Therefore, it is unlikely that impairment from diphenhydramine degraded the pilot's ability to safely operate the gyroplane. The clinical findings of an elevated hemoglobin A1C (9.2%) and elevated glucose in the urine is consistent with poorly controlled diabetes. The hemoglobin A1C of 9.2% correlates with an average blood sugar level of about 250 mg/ml (below 140 mg/ml is normal). Blood sugar elevated into this range causes few identified symptoms other than increased urination and is not acutely impairing. However, long-term diabetes can cause loss of vision, neuropathy in the lower limbs, and kidney disease. The investigation could not determine if the pilot had any symptoms from diabetes or its long-term complications.

Examination of the airframe, engine, and flight control system components revealed no evidence of preimpact mechanical malfunctions or anomalies that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for ERA13FA219 for the full record.