Narrative:

On or about XX00, I landed at commodore heliport from doing traffic watch. I rolled the throttle back to 70 percent N1 and applied cyclic friction. There was minimal friction on the collective. I then exited the helicopter and refueled it. After replacing the fuel hose at the refueling station, I took a ladder to the left side of the aircraft, raised the left engine cowling, performed a quick leak check and closed the cowling. As I was removing the ladder back to its storage area I heard the engine RPM increase. The aircraft then picked up into the air, the tail rotor struck the ground, the helicopter then rolled onto its right side. There were no occupants in the aircraft. There were no injuries or property damage other than damage to the aircraft itself and a wood box at the heliport. NTSB was notified by operator. NTSB stated this was an incident not requiring notification. The FAA from oak FSDO came and looked and took a report, looked at aircraft. Leaving an aircraft engine running without a pilot at the controls is a stupid thing to do. From now on I will not leave the aircraft until the engine is shut down and the rotor blades are stopped. I believe this incident occurred because the cyclic possibly moved forward causing the collective to begin to raise with the throttle opening enough for the helicopter to lift off. I believe this could be the cause of the uncommanded engine acceleration.

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Original NASA ASRS Text

Title: PLT OF ROTARY WINGED ACFT LEAVES BLADES TURNING WHILE EXITING ACFT FOR GND REFUELING PROC. THROTTLE CREEPS OPEN, ACFT LIFTS OFF AND FALLS OVER. ACFT DAMAGED.

Narrative: ON OR ABOUT XX00, I LANDED AT COMMODORE HELIPORT FROM DOING TFC WATCH. I ROLLED THE THROTTLE BACK TO 70 PERCENT N1 AND APPLIED CYCLIC FRICTION. THERE WAS MINIMAL FRICTION ON THE COLLECTIVE. I THEN EXITED THE HELI AND REFUELED IT. AFTER REPLACING THE FUEL HOSE AT THE REFUELING STATION, I TOOK A LADDER TO THE L SIDE OF THE ACFT, RAISED THE L ENG COWLING, PERFORMED A QUICK LEAK CHK AND CLOSED THE COWLING. AS I WAS REMOVING THE LADDER BACK TO ITS STORAGE AREA I HEARD THE ENG RPM INCREASE. THE ACFT THEN PICKED UP INTO THE AIR, THE TAIL ROTOR STRUCK THE GND, THE HELI THEN ROLLED ONTO ITS R SIDE. THERE WERE NO OCCUPANTS IN THE ACFT. THERE WERE NO INJURIES OR PROPERTY DAMAGE OTHER THAN DAMAGE TO THE ACFT ITSELF AND A WOOD BOX AT THE HELIPORT. NTSB WAS NOTIFIED BY OPERATOR. NTSB STATED THIS WAS AN INCIDENT NOT REQUIRING NOTIFICATION. THE FAA FROM OAK FSDO CAME AND LOOKED AND TOOK A RPT, LOOKED AT ACFT. LEAVING AN ACFT ENG RUNNING WITHOUT A PLT AT THE CTLS IS A STUPID THING TO DO. FROM NOW ON I WILL NOT LEAVE THE ACFT UNTIL THE ENG IS SHUT DOWN AND THE ROTOR BLADES ARE STOPPED. I BELIEVE THIS INCIDENT OCCURRED BECAUSE THE CYCLIC POSSIBLY MOVED FORWARD CAUSING THE COLLECTIVE TO BEGIN TO RAISE WITH THE THROTTLE OPENING ENOUGH FOR THE HELI TO LIFT OFF. I BELIEVE THIS COULD BE THE CAUSE OF THE UNCOMMANDED ENG ACCELERATION.

Data retrieved from NASA's ASRS site as of July 2007 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.