Aviation Accident Summaries

Aviation Accident Summary BFO94LA105

ELIZABETHTOWN, KY, USA

Aircraft #1

N2346J

ROBINSON R22 BETA

Analysis

THE PILOT AND PASSENGER WERE DEPARTING FROM A LOT THAT WAS SURROUNDED BY OBSTRUCTIONS. ACCORDING TO THE PILOT, HE TOOK OFF IN A HOVER, THEN AS THE HELICOPTER WAS PASSING TREES AT ABOUT 70 FEET AND 30 TO 35 KNOTS, IT BEGAN SPINNING TO THE RIGHT. HE SAID HE TRIED TO STOP THE TURNING WITH LEFT PEDAL, WHICH DID NOT CORRECT THE PROBLEM. HE ENTERED AN AUTOROTATION TO A ROAD. DURING THE AUTOROTATIVE LANDING, THE HELICOPTER TOUCHED DOWN HARD, DAMAGING THE UNDERSIDE OF THE AIRFRAME. ACCORDING TO WITNESSES, THE MAIN ROTOR BLADES CLIPPED A TREE, BUT NO BLADE DAMAGE WAS REPORTED. POST-ACCIDENT EXAMINATION REVEALED NO PREIMPACT MECHANICAL DISCREPANCIES. ACCORDING TO THE HEIGHT-VELOCITY DIAGRAM IN THE R22 OPERATING HANDBOOK, DIRECTIONAL CONTROL WAS LOST WHEN THE HELICOPTER WAS OUTSIDE THE AREA FOR THE 'RECOMMENDED TAKE-OFF PROFILE' (AIRSPEED/ALTITUDE ENVELOPE FOR A SUCCESSFUL AUTOROTATION).

Factual Information

On June 17, 1994, about 1200 eastern daylight time, a Robinson R-22 Beta, N2346J, was substantially damaged during a hard landing that followed an autorotation, in Elizabethtown, Kentucky. The pilot and passenger were not injured. The personal flight was being operated by J.R. Aviation, Elizabeth, Indiana. Visual meteorological conditions prevailed. The flight was being conducted under CFR 14 Part 91. In the NTSB form 6120.1/2, the pilot stated, I took off at back end of gravel lot behind First Christian Church of Elizabethtown. All gauges looked normal, so proceeded to hover then forward flight. As I passed by trees to my right at approximately 30 to 35 knots [the] airplane started to spin to [the] right. I tried to enter left pedal to stop turning. After noting this was not correcting the problem, I lowered the collective to try to arrest the rotation. After two 360 degree spins, I entered autorotation to road.... At the termination of the autorotation, the helicopter landed hard causing damage to the underside of the airframe. According to witness statements and a police report, the helicopter struck a tree prior to landing. Post accident examination by a Federal Aviation Administration Inspector revealed no mechanical discrepancies with the helicopter or the engine. According to the height-velocity diagram in the R-22 Pilot's Operating Handbook, between 0-53 knots and 15-400 feet, was an area outside of the "RECOMMENDED TAKE-OFF PROFILE" area.

Probable Cause and Findings

THE PILOT'S FAILURE TO MAINTAIN DIRECTIONAL CONTROL. A FACTOR RELATED TO THE ACCIDENT WAS: THE HELICOPTER WAS OUTSIDE THE HEIGHT-VELOCITY ENVELOPE (FOR A SUCCESSFUL AUTOROTATION), WHEN LOSS OF DIRECTIONAL CONTROL OCCURRED.

 

Source: NTSB Aviation Accident Database

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