Pilot Debrief

ENSTROM 280 near Port Orange, FL — 2021-08-21

Final reportERA21LA339
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Date
2021-08-21
Location
Port Orange, FL, USA
Airport
7FL6
Aircraft
ENSTROM 280
Registration
N9285
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Landing

Probable cause

The failure of the tail rotor drive shaft at the coupling due to torsionally applied shear stress.

NTSB narrative

The pilot was conducting a local flight when just prior to touchdown, the helicopter began to spin to the right and made an uncommanded climb and spin to the right. The pilot applied full left rudder pedal, but the helicopter continued to spin to the right. He lowered the collective and landed hard on the skids, which resulted in substantial damage to the fuselage. Postaccident examination of the helicopter revealed the tail rotor driveshaft was separated and free to spin inside the coupling. Metallurgical examination of the driveshaft revealed the bolt holes in the driveshaft were distorted, consistent with torsional shear-stress in the clockwise direction.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have checked tail rotor drive shaft connection before flight.

NTSB coding

Evidence available

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

Docket documents7

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