Hughes OH-6A N6641D

Summary

On 4 June 2009 at about 15:50 local time, a Hughes OH-6A registered N6641D, operated by Dept of Homeland Security, was involved in an accident near Benson, Arizona, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

4 June 2009 at 15:50

Classification

Accident

Location

Benson, Arizona, United States

Nearest airport

Benson Municipal Airport (E95)

Coordinates

31.9994, -110.3578

Aircraft

Hughes OH-6A

Registration

N6641D

Category

Helicopter

Engines

1

Operator

Dept of Homeland Security

Operating rule

Part 91: General Aviation

Phase of flight

Not recorded

Route

Tucson → Benson

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR09TA277

Nobody was injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full 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.

Quoted verbatim from the NTSB record.