Pilot Debrief

BIELAWA ROTORWAY E near Sequim, WA — 2009-07-16

Final reportWPR09LA350
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Date
2009-07-16
Location
Sequim, WA, USA
Airport
W28
Aircraft
BIELAWA ROTORWAY E
Registration
N3213K
Category
Helicopter
Highest injury
Minor
Fatalities
0
Phase of flight
Hover

Probable cause

The failure (disbonding) of a composite main rotor blade for undetermined reasons, leading to an immediate loss of control in flight during hover.

NTSB narrative

During a stationary low hover of the recently built experimental helicopter, it suddenly and without warning rotated rapidly in a counter-clockwise direction around its longitudinal axis, and immediately impacted the ground. The investigation determined that one of the main rotor blades had failed (disbonded), leading to an immediate loss of control in flight. The composite blade, which was designed specifically for use on one manufacturer's experimental helicopter, was being used on another manufacturer's experimental helicopter, as allowed by its experimental designation. Due to the lack of sufficient engineering, manufacturing, and testing data, the precise initiating factor of the disbonding event could not be determined.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Use of non-manufacturer approved rotor blades for the helicopter.

NTSB coding

Evidence available

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

Docket documents5

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