Narrative:

I returned to my car with the intention of returning to my office for a headset when I remembered that my flight helmet was in the trunk. I returned to the aircraft with my flight helmet and, once again as is my normal custom before flying a helicopter, I walked completely around the machine, specifically checking for loose panels, doors, and seatbelts. I started the aircraft and lifted from the dolly. I had to hover next to the dolly for about 1 min to establish contact with the tower. I then departed toward the southeast into the wind, accelerated to 60 mph, and climbed at that airspeed. I began my turn to a northwest heading approximately over the jet hangars, and leveled off at about 300 ft. It was my intention to fly a circle of approximately 1 mi diameter back to the FBO ramp. As I leveled off and the aircraft accelerated, everything was normal until the airspeed reached about 120 mph, at which time I heard 2 thumps and felt the helicopter shake. I immediately lowered the collective, reduced my speed and noted a large field about 1/2 a mi ahead. I reported to the tower that I was going to make a precautionary landing, the controller told me to report when landing was assured. The helicopter flew perfectly normally during the approach, I landed and shut down uneventfully, and noted that the left engine access door had come open in-flight and struck the main rotor blades. I reported the problem to X via telephone, he drove me back to the airport where I contacted the fll FSDO of the FAA.I spoke with Y at XA55 and told him what had happened, and that I was not sure what had caused the incident, but that FBO had another helicopter identical to the incident machine and would replace the damaged blades and engine covers with parts from this aircraft. Y said that he had no problem with this, but told me to be sure that the work was properly accomplished in accordance with maintenance procedures and checked by a mechanic. He told me he felt that the cause was very likely a latch failure, and asked that an FAA malfunction and defect report be filed. The blades and engine cowling were changed, and the aircraft returned to FBO without further incident.

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Original NASA ASRS Text

Title: ENG COWL STRUCK ROTOR, RPTR DID AN EMER OFF ARPT LNDG.

Narrative: I RETURNED TO MY CAR WITH THE INTENTION OF RETURNING TO MY OFFICE FOR A HEADSET WHEN I REMEMBERED THAT MY FLT HELMET WAS IN THE TRUNK. I RETURNED TO THE ACFT WITH MY FLT HELMET AND, ONCE AGAIN AS IS MY NORMAL CUSTOM BEFORE FLYING A HELI, I WALKED COMPLETELY AROUND THE MACHINE, SPECIFICALLY CHKING FOR LOOSE PANELS, DOORS, AND SEATBELTS. I STARTED THE ACFT AND LIFTED FROM THE DOLLY. I HAD TO HOVER NEXT TO THE DOLLY FOR ABOUT 1 MIN TO ESTABLISH CONTACT WITH THE TWR. I THEN DEPARTED TOWARD THE SE INTO THE WIND, ACCELERATED TO 60 MPH, AND CLBED AT THAT AIRSPD. I BEGAN MY TURN TO A NW HDG APPROX OVER THE JET HANGARS, AND LEVELED OFF AT ABOUT 300 FT. IT WAS MY INTENTION TO FLY A CIRCLE OF APPROX 1 MI DIAMETER BACK TO THE FBO RAMP. AS I LEVELED OFF AND THE ACFT ACCELERATED, EVERYTHING WAS NORMAL UNTIL THE AIRSPD REACHED ABOUT 120 MPH, AT WHICH TIME I HEARD 2 THUMPS AND FELT THE HELI SHAKE. I IMMEDIATELY LOWERED THE COLLECTIVE, REDUCED MY SPD AND NOTED A LARGE FIELD ABOUT 1/2 A MI AHEAD. I RPTED TO THE TWR THAT I WAS GOING TO MAKE A PRECAUTIONARY LNDG, THE CTLR TOLD ME TO RPT WHEN LNDG WAS ASSURED. THE HELI FLEW PERFECTLY NORMALLY DURING THE APCH, I LANDED AND SHUT DOWN UNEVENTFULLY, AND NOTED THAT THE L ENG ACCESS DOOR HAD COME OPEN INFLT AND STRUCK THE MAIN ROTOR BLADES. I RPTED THE PROB TO X VIA TELEPHONE, HE DROVE ME BACK TO THE ARPT WHERE I CONTACTED THE FLL FSDO OF THE FAA.I SPOKE WITH Y AT XA55 AND TOLD HIM WHAT HAD HAPPENED, AND THAT I WAS NOT SURE WHAT HAD CAUSED THE INCIDENT, BUT THAT FBO HAD ANOTHER HELI IDENTICAL TO THE INCIDENT MACHINE AND WOULD REPLACE THE DAMAGED BLADES AND ENG COVERS WITH PARTS FROM THIS ACFT. Y SAID THAT HE HAD NO PROB WITH THIS, BUT TOLD ME TO BE SURE THAT THE WORK WAS PROPERLY ACCOMPLISHED IN ACCORDANCE WITH MAINT PROCS AND CHKED BY A MECH. HE TOLD ME HE FELT THAT THE CAUSE WAS VERY LIKELY A LATCH FAILURE, AND ASKED THAT AN FAA MALFUNCTION AND DEFECT RPT BE FILED. THE BLADES AND ENG COWLING WERE CHANGED, AND THE ACFT RETURNED TO FBO WITHOUT FURTHER INCIDENT.

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.