Pilot Debrief

MD Helicopters Inc MD 902 near Salinas, CA — 2008-07-21

Final reportLAX08IA241
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Date
2008-07-21
Location
Salinas, CA, USA
Airport
SNS
Aircraft
MD Helicopters Inc MD 902
Registration
N902CS
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Hover

Probable cause

The pilot's inability to maintain directional control due to the fatigue failure of the threaded portion of the forward directional control cable as a result of the improper installation a lock washer.

NTSB narrative

During the approach to land, the pilot reported that he brought the helicopter to an 8- to 10-foot hover when the nose broke to the right and the helicopter started an uncommanded right spin. The pilot's attempt to correct with full left pedal failed to stop the spin. The pilot then initiated a hovering autorotation, which resulted in a hard landing and minor damage to the landing skids. The postaccident airframe inspection revealed that the threaded portion of the rear of the forward directional control cable of the no tail rotor (NOTAR) had separated. The forward directional control cable and the rotating cone control rod of the NOTAR, as well as associated hardware, were sent to an NTSB specialist for a detailed examination. The examination of the cable and associated hardware revealed that the cable had failed in fatigue due to the misplacement of the lock washer that was located between the cable's telescopic part and the rotating cone control rod.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have aborted the landing when noticing excessive left pedal usage.

NTSB coding

  • Flight control sys malf/fail · Landing
  • Maintenance

Evidence available

  • 5 docket documents
View NTSB final reportView NTSB docket

Docket documents5

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