Pilot Debrief

HOFFMAN ZENITH 701 near Trinidad, CO — 2015-04-30

Final reportCEN15FA211
Sign in to save
Date
2015-04-30
Location
Trinidad, CO, USA
Aircraft
HOFFMAN ZENITH 701
Registration
N95MH
Category
Airplane
Highest injury
Fatal
Fatalities
1
Phase of flight
Maneuvering

Probable cause

The noncertificated pilot's failure to maintain airspeed following a loss of engine power while maneuvering at a low altitude, which resulted in the airplane's wing exceeding its critical angle-of-attack and a subsequent aerodynamic stall. The reason for the loss of engine power could not be determined because postaccident examination revealed no evidence of mechanical failure or malfunction.

NTSB narrative

The noncertificated pilot was conducting a personal flight in the experimental amateur-built airplane. A witness reported seeing the airplane circling overhead about 200 to 300 ft above ground level. According to the witness, the airplane's engine was running normally. The witness reported that during the third circle, the airspeed was low, the wings were level, and the pilot was turning the airplane using only the rudder. The witness heard the engine noise stop, and the airplane "flipped over to the left" and descended in a nose-down attitude to ground impact. Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The propeller blades displayed no evidence of rotational damage, indicating that the engine was not producing power at ground impact. An engine run was conducted, and the engine started and ran smoothly. Although it is possible that the uncoordinated (wings level) turns the pilot was making caused fuel to move away from the fuel tank ports resulting in fuel starvation, the reason for the loss of engine power was not determined. The pilot did not hold any type of pilot certificate, a medical certificate, or a valid driver's license and his flight time is unknown. It is likely that as the pilot maneuvered the airplane at a low altitude, he allowed the airspeed to decay to the point of exceeding the wing's critical angle-of-attack, which resulted in an aerodynamic stall. Further, it is likely that the pilot was lacking in flight training and experience, which prevented him from maintaining control of the airplane. Toxicological testing identified diphenhydramine, a sedating antihistamine, in the pilot's blood and urine, but the pilot's decision to perform turns at low altitude was likely not due to the effects of diphenhydramine.

Analysis

Primary failure mode
Fuel management
First missed decision gate
Pilot could have ensured adequate fuel before attempting maneuvers.

NTSB coding

Evidence available

  • Photos
  • 7 docket documents
View NTSB final reportView NTSB docket

Docket documents7

Related mishaps