NTSB Identification: CHI01LA178.
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Accident occurred Monday, June 18, 2001 in Eldridge, IA
Probable Cause Approval Date: 05/21/2002
Aircraft: Enstrom F-28A, registration: N612B
Injuries: 1 Serious,1 Minor.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The helicopter pilot said, "...(5) Preflighted, got in, shut doors, seat belts on, headset on, started, warmed up then picked up to a 3 [foot] hover. Everything was in the green and looked normal. I then rotated 180 [degrees] to transition out, stopped, everything looked normal. (6) I then added full power, lower cyclic and slightly raised collective to start moving [forward]. As we climbed to about 15-17 [feet], we heard a coughing sound, then silent. Engine quit, I tried to get it back on the ground as flat and level as possible. You can not auto[rotate] at 17 [feet]." A Federal Aviation Administration publication states, "A height/velocity (H/V) diagram, published by the manufacturer for each model of helicopter, depicts the critical combinations of airspeed and altitude should an engine failure occur. Operating at the altitudes and airspeeds shown within the crosshatched or shaded areas of the H/V diagram may not allow enough time for the critical transition from powered flight to autorotation." The helicopter flight manual states, "... The effects of wind on take-off and landings are important factors and should be considered in the operation of the helicopter; however, in planning critical helicopter operations, the effects of winds can be relied upon to assist in accomplishing landings and take-offs from unobstructed areas. If the helicopter were riding a gust of wind on the final approach and the gust should decrease as the helicopter was approaching a hover, the helicopter would probably rapidly 'settle' if the wind factor was planned on to execute the landing. This condition would also hold true during the initial phase of take-off. ... Another effect of wind that must be considered is the 'lee' effect of the wind over hills, ridges, and obstacles. The downdrafts resulting from these conditions particularly affect the initial phase of take-off or the final phase of landing." A postaccident examination of the helicopter and accident site was conducted. The helicopter was found facing in a northerly direction in an open, flat, unobstructed field. There were buildings to the south of the field. No anomalies were found with respect to the helicopter. The winds were reported to be from 200 degrees at 17 knots gusting to 22 knots with a peak wind of 210 degrees at 26 knots.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The inadequate autorotation and disregarded wind information by the pilot. Factors were the gusting tailwind and the loss of engine power for undetermined reasons. Full narrative available
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