Amateur-built DeBird N140DG accident near Napoleon, Michigan

Probable cause

Separation of the gyroplane’s tail due to main rotor blade contact for reasons that could not be determined.

NTSB analysis

The pilot’s husband reported that his wife was conducting an evening pleasure flight in the accident gyroplane. He heard the gyroplane taxi to the runway and begin its takeoff. He said he did not hear anything unusual until he heard two loud thumps. The gyroplane was later located in a wooded area left of the departure runway. There were no witnesses to the accident and no flight track data was available.

Examination of the gyroplane did not reveal any preimpact anomalies that would have precluded normal operations. The gyroplane’s tail surfaces were found separated from the rest of the gyroplane with unbroken trees between the resting location of the tail surfaces and the main wreckage. Additionally, impact marks and paint transfer on the rotor blades, tail, and tail boom were consistent with the main rotor blades impacting the tail. It is most likely that the main rotors impacted the tailboom which resulted in the separation of the tail.

Main rotor blade contact with the tail would have rendered the gyroplane uncontrollable. Based on the design of the gyroplane, the rotor blades would have had to droop a significant amount in order to contact the tail boom. Without flight track, engine, or rotor speed data to assist the investigation, the reason that the main rotor blade contacted the tail boom could not be determined.

The pilot’s postmortem toxicological testing indicated that the pilot had used the sedating antihistamine medication diphenhydramine. However, diphenhydramine testing in cavity blood was inconclusive. Based on these results, it was not possible to determine whether the pilot had used diphenhydramine recently enough to be experiencing impairing effects at the time of the accident

Text from the NTSB. Open the NTSB docket for CEN24FA298 for the full record.