Narrative:

Introduction: on a clear warm humid summer day with a stiff breeze of about 8-10 KTS out of the northwest I was giving event attendees rides over the lake in a bell 47 helicopter. I had completed many rides that day; which lasted about 5 mins each. Uneven heating of the surface caused turbulence at several locations on the route. On this flight I completed the takeoff and then turned left continuing to climb to our crosswind turn to the right and final cruise altitude of about 1000 ft AGL. As I banked right and crossed the lake shoreline I hit turbulence and the aircraft yawed left and then silence; the engine hesitated and suddenly quit. I entered an autorotation and selected my landing spot; which required a 180 degree turn to the left to land into the wind in a low growth cornfield. The descent; flare and landing was accomplished and no injuries or damage resulted from the successful autorotation. The passenger were reassured and another helicopter was summoned to pick up the passenger and return them to the base of operations. Corrective action: reserve fuel will be kept to 30 mins minimum. Stop clock will continue to be used to validate burn rate and helicopter will only be dipped on level ground. Pilots will be cautioned to minimize bank in turns when approaching reserve fuel status especially when experiencing turbulence.

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Original NASA ASRS Text

Title: BELL 47 PILOT REPORTS ENGINE FAILURE AND SUCCESSFUL AUTO ROTATION FROM 800 FT AGL. FUEL STARVATION WAS SUSPECTED DUE TO MANEUVERING WITH RESERVE FUEL.

Narrative: INTRODUCTION: ON A CLR WARM HUMID SUMMER DAY WITH A STIFF BREEZE OF ABOUT 8-10 KTS OUT OF THE NW I WAS GIVING EVENT ATTENDEES RIDES OVER THE LAKE IN A BELL 47 HELI. I HAD COMPLETED MANY RIDES THAT DAY; WHICH LASTED ABOUT 5 MINS EACH. UNEVEN HEATING OF THE SURFACE CAUSED TURB AT SEVERAL LOCATIONS ON THE RTE. ON THIS FLT I COMPLETED THE TKOF AND THEN TURNED L CONTINUING TO CLB TO OUR XWIND TURN TO THE R AND FINAL CRUISE ALT OF ABOUT 1000 FT AGL. AS I BANKED R AND CROSSED THE LAKE SHORELINE I HIT TURB AND THE ACFT YAWED L AND THEN SILENCE; THE ENG HESITATED AND SUDDENLY QUIT. I ENTERED AN AUTOROTATION AND SELECTED MY LNDG SPOT; WHICH REQUIRED A 180 DEG TURN TO THE L TO LAND INTO THE WIND IN A LOW GROWTH CORNFIELD. THE DSCNT; FLARE AND LNDG WAS ACCOMPLISHED AND NO INJURIES OR DAMAGE RESULTED FROM THE SUCCESSFUL AUTOROTATION. THE PAX WERE REASSURED AND ANOTHER HELI WAS SUMMONED TO PICK UP THE PAX AND RETURN THEM TO THE BASE OF OPS. CORRECTIVE ACTION: RESERVE FUEL WILL BE KEPT TO 30 MINS MINIMUM. STOP CLOCK WILL CONTINUE TO BE USED TO VALIDATE BURN RATE AND HELI WILL ONLY BE DIPPED ON LEVEL GND. PLTS WILL BE CAUTIONED TO MINIMIZE BANK IN TURNS WHEN APCHING RESERVE FUEL STATUS ESPECIALLY WHEN EXPERIENCING TURB.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.