Flight Details
On June 4, 2009, at 0850 mountain standard time, a Hughes OH-6A, registration N6641D, experienced a hard landing at Benson Municipal Airport, Benson, Arizona. The flight was operated by U.S. Customs and Border Protection as a public-use pilot training flight under 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from Tucson International Airport, Tucson, Arizona, at 0715.
Accident Sequence
The instructor pilot reported that they were practicing autorotations to the runway. During a straight-in autorotation at approximately 200 feet above ground level (AGL), the instructor called for an increase in throttle to bring rotor rpm into the normal operating range in preparation for landing. Between 200 and 100 feet AGL, the instructor assisted the flying pilot with the throttle increase after realizing the pilot had delayed throttle application. The flying pilot initiated the flare at approximately 50 feet AGL, then 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. During the second touchdown, it rotated to the left of runway heading, resulting in the collapse of the right landing skid. The helicopter came to rest oriented 150 degrees to the left of runway heading.
Aircraft Examination
Examination by a Federal Aviation Administration (FAA) inspector revealed structural damage to the right landing skid and the fuselage. The pilot reported no mechanical anomalies with the flight control systems prior to the flight.
Weather Conditions
Weather reported at Fort Huachuca, Arizona, 24 miles south of the accident location, at 0755 MST, indicated wind variable at 1 knot, visibility 50 miles, and a ceiling of 20,000 feet.