Pilot Debrief

Hughes 369A near St Louis, MO — 2020-08-06

Final reportCEN20CA326
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Date
2020-08-06
Location
St Louis, MO, USA
Airport
KSUS
Aircraft
Hughes 369A
Registration
N911EP
Category
Helicopter
Highest injury
None
Fatalities
0

Probable cause

The flight instructor's failure to maintain helicopter control which resulted in a hard landing while preforming a practice autorotation.

NTSB narrative

The instructor reported that during the instructional flight, he was manipulating the controls and accepted the option to land on the taxiway; he decreased the throttle for a full touchdown auto rotation. About 50 ft above the ground (agl), he flared the helicopter and leveled off about 5 to 10 ft agl. The instructor reported that everything seemed "normal" at this point. He then raised the collective, but the descent was not arrested, so he raised the collective full up. The helicopter landed hard and shook violently. The instructor closed the throttle to which stopped the fuel supply. The tailboom was substantially damaged. The flight instructor reported that there were no mechanical anomalies with the helicopter that would have precluded normal operation. The instructor added that he felt a slight tailwind after exiting the helicopter and that the tail wind caused a "vortex ring state" which stalled the main rotor blades.

NTSB coding

Evidence available

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

Docket documents2

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