Pilot Debrief

HUGHES OH-6A near Benson, AZ — 2009-06-04

Final reportWPR09TA277
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Date
2009-06-04
Location
Benson, AZ, USA
Airport
E95
Aircraft
HUGHES OH-6A
Registration
N6641D
Category
Helicopter
Highest injury
None
Fatalities
0
Phase of flight
Approach

Probable cause

The pilot under instruction's inadequate autorotation technique and the instructor pilot’s delayed remedial action to arrest the rate of descent of the helicopter while in an autorotation flare.

NTSB narrative

The instructor pilot reported that they were practicing autorotations to the runway. During a straight-in autorotation at approximately 200 feet above ground level, the instructor called for an increase in throttle to bring rotor rpm into the normal operating range in preparation for landing. Between 200 feet and 100 feet agl, the instructor assisted the flying pilot with the throttle increase when he realized that the pilot had delayed throttle application. The flying pilot then initiated the flare at approximately 50 feet agl. The flying pilot leveled the helicopter and applied collective to slow the descent rate. Upon realizing that the descent rate had not been checked prior to beginning the flare, the instructor joined the flying pilot on the controls. The helicopter landed hard on the runway and bounced, rotated to the left of runway heading as it touched down a second time, resulting in the collapse of the right landing skid. The pilot reported that were no mechanical anomalies with the flight control systems.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Throttle application was delayed before initiating the flare.

NTSB coding

Evidence available

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

Docket documents3

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