Aviation Accident Summaries

Aviation Accident Summary MIA96LA191

LUTZ, FL, USA

Aircraft #1

N5061F

Fairchild Hiller FH1100

Analysis

The pilot stated that he was ground running a helicopter and did not intend to takeoff. He increased the collective pitch, and the helicopter became light on the skids and pulled to the right. The pilot applied left cyclic, but the helicopter rolled over on its right side. Examination of the crash site revealed gouge marks to the right rear of the helipad. Dirt was present on the right rear skid of the helicopter. The pilot believed there was a problem with the lateral trim unit; however, an examination of the cyclic force trim revealed no malfunction or abnormality or lack of movement of the cyclic control with the force trim engaged.

Factual Information

On July 19, 1996, about 0945 eastern daylight time, an unregistered Fairchild FH1100, N5016, operating as a 14 CFR Part 91 personal flight, crashed on takeoff in the vicinity of Lutz, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The helicopter sustained substantial damage. The private pilot sustained serious injuries. The flight was originating from a private residence at the time of the accident. The pilot stated on the NTSB Pilot/Operator Aircraft Accident Report that he was ground running the helicopter with no intention of flight. He pulled slight collective pitch and the helicopter became light on the skids. The helicopter pulled to the right. He applied left cyclic, and the helicopter rolled over on its right side. The pilot stated, "A later investigation revealed failure of the lateral trim unit which caused the left cyclic to jam, resulting in no lateral control of the aircraft, which was the reason for the accident." Examination of the crash site by the FAA, revealed several main rotor blades impact marks on the ground on the right side of the helicopter. A gouge mark or impact mark was present at the right rear of the helipad where the helicopter was parked. The mark was about 6 inches long and 3 inches wide. Dirt was present on the right rear skid. Examination of the cyclic force trim revealed no malfunction or abnormalities or lack of movement of cyclic control with the force trim engaged. The FAA accident coordinator was contacted as a result of a letter submitted by the accident pilot to the NTSB on November 5, 1998. The FAA inspector stated in a subsequent statement, "During a second visit to the accident site, Mr. Chapman's backyard, I checked the movement of all the flight controls. Reaching down into the aircraft there was initial resistance of movement of the cyclic. I then handed my notebook that I was carrying in my left hand to Mrs. Chapman and repositioned my arm to simulate the approximate position of a pilot sitting in the aircraft. The cyclic moved fore and aft and right lateral direction, there was some resistance in the left lateral direction but with a slight amount of pressure the cyclic moved freely. Mr. Chapman mentioned this point several times in our telephone conversation stating that the cyclic was "jammed" because of the force trim. In this inspector's opinion, under the circumstances and amount of resistance of left lateral cyclic was not significant enough to be a single causal factor of the accident."

Probable Cause and Findings

the pilot's improper use of the flight controls (collective and cyclic), while conducting a ground run, resulting in a roll over.

 

Source: NTSB Aviation Accident Database

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