Pilot Debrief

HUGHES 269B near Edgerton, IN — 2011-04-29

Final reportCEN11LA315
Sign in to save
Date
2011-04-29
Location
Edgerton, IN, USA
Airport
VNW
Aircraft
HUGHES 269B
Registration
N9561F
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Climb

Probable cause

A loss of clearance between the tail rotor drive shaft and the tailboom bulkhead for undetermined reasons, which resulted in the overstress failure of the drive shaft.

NTSB narrative

The pilot reported a vibration in the helicopter antitorque pedals and a subsequent loss of directional control. The pilot initiated an autorotation to a field, and the helicopter sustained damage to the left landing skid and fuselage. A postaccident examination revealed that the tail rotor drive shaft failed due to an overstress fracture that resulted from contact with the tailboom bulkhead. Examination of the tailboom support structure was unable to determine the underlying cause of the contact between the tailboom and drive shaft. The operator reported that he was not aware of any events prior to the accident that would have compromised the tailboom support structure.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Inspect tail rotor drive shaft for damage before returning to service.

NTSB coding

Evidence available

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

Docket documents5

Related mishaps