Narrative:

I took off on an far part 91 flight from sbp for the big sur coastline with the owner of the aircraft. Approximately 6 mi northwest of the airport, we heard a thunk. I looked into the mirror and saw that the starboard engine cowling was loose. I immediately made an emergency landing on top of a hilltop that is part of a horse pasture. The landing was normal. Rotor RPM never dropped and power and vibration levels were normal. Upon shutdown, I could see that the lower third of the cowling had been torn away and that the rotor blades had been scratched near the blade root, primarily on the stainless steel leading edge. There was no evidence of any contact or damage to the tail, horizontal or vertical stabilizers of the adjacent cowlings. There was no evidence of foreign object ingestion into the engine. The intake was clean and the screen was undamaged. I know why this incident happened. When we were going through the start problem and hit the starter, nothing happened. We ran through the procedure again and once more it didn't crank. I checked the circuit breakers and then remembered something I had learned in the EC120 course. There is a microswitch on the rotor brake that will not let the starter engage if the rotor brake is on. They had told us that it occasionally sticks. So, I took the plastic end of a screwdriver and tapped the switch. Then, I lowered the cowling without latching it because I wasn't planning to start. I just wanted to tap the starter switch to see if it would engage. It did. The tap had solved the problem. I was excited that I had found the problem. I then got out of the ship and looked aft to be sure the cowling was closed and forgot that I had left it unlatched. I broke a fundamental rule of mine, which is to always walk around the aircraft just before you get in to check obvious things such as latches, fuel cap, tie-downs, covers, and rotor blade conditions. As of this writing, the helicopter is still on the hilltop.

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Original NASA ASRS Text

Title: PLT OF EC120 HELI MAKES FORCED OFF FIELD LNDG NEAR SBP AFTER COWLING LEFT UNLATCHED BEFORE TKOF COMES OFF AND CONTACTS MAIN ROTOR.

Narrative: I TOOK OFF ON AN FAR PART 91 FLT FROM SBP FOR THE BIG SUR COASTLINE WITH THE OWNER OF THE ACFT. APPROX 6 MI NW OF THE ARPT, WE HEARD A THUNK. I LOOKED INTO THE MIRROR AND SAW THAT THE STARBOARD ENG COWLING WAS LOOSE. I IMMEDIATELY MADE AN EMER LNDG ON TOP OF A HILLTOP THAT IS PART OF A HORSE PASTURE. THE LNDG WAS NORMAL. ROTOR RPM NEVER DROPPED AND PWR AND VIBRATION LEVELS WERE NORMAL. UPON SHUTDOWN, I COULD SEE THAT THE LOWER THIRD OF THE COWLING HAD BEEN TORN AWAY AND THAT THE ROTOR BLADES HAD BEEN SCRATCHED NEAR THE BLADE ROOT, PRIMARILY ON THE STAINLESS STEEL LEADING EDGE. THERE WAS NO EVIDENCE OF ANY CONTACT OR DAMAGE TO THE TAIL, HORIZ OR VERT STABILIZERS OF THE ADJACENT COWLINGS. THERE WAS NO EVIDENCE OF FOREIGN OBJECT INGESTION INTO THE ENG. THE INTAKE WAS CLEAN AND THE SCREEN WAS UNDAMAGED. I KNOW WHY THIS INCIDENT HAPPENED. WHEN WE WERE GOING THROUGH THE START PROB AND HIT THE STARTER, NOTHING HAPPENED. WE RAN THROUGH THE PROC AGAIN AND ONCE MORE IT DIDN'T CRANK. I CHKED THE CIRCUIT BREAKERS AND THEN REMEMBERED SOMETHING I HAD LEARNED IN THE EC120 COURSE. THERE IS A MICROSWITCH ON THE ROTOR BRAKE THAT WILL NOT LET THE STARTER ENGAGE IF THE ROTOR BRAKE IS ON. THEY HAD TOLD US THAT IT OCCASIONALLY STICKS. SO, I TOOK THE PLASTIC END OF A SCREWDRIVER AND TAPPED THE SWITCH. THEN, I LOWERED THE COWLING WITHOUT LATCHING IT BECAUSE I WASN'T PLANNING TO START. I JUST WANTED TO TAP THE STARTER SWITCH TO SEE IF IT WOULD ENGAGE. IT DID. THE TAP HAD SOLVED THE PROB. I WAS EXCITED THAT I HAD FOUND THE PROB. I THEN GOT OUT OF THE SHIP AND LOOKED AFT TO BE SURE THE COWLING WAS CLOSED AND FORGOT THAT I HAD LEFT IT UNLATCHED. I BROKE A FUNDAMENTAL RULE OF MINE, WHICH IS TO ALWAYS WALK AROUND THE ACFT JUST BEFORE YOU GET IN TO CHK OBVIOUS THINGS SUCH AS LATCHES, FUEL CAP, TIE-DOWNS, COVERS, AND ROTOR BLADE CONDITIONS. AS OF THIS WRITING, THE HELI IS STILL ON THE HILLTOP.

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.