EMERGENCY LNDG BY HELICOPTER DUE TO SMOKE WARNING.

Narrative

AFTER GETTING A CHIP LIGHT ON MY #2 ENG MAINT WAS PERFORMED AND I WAS RUNNING THIS ENG WITH THE COWLING BACK AND THE ROTOR BRAKE ON FOR A LEAK CHK. I THEN SHUT DOWN THE ENG AND WAITED AT THE CONTROLS FOR THE MECH TO SECURE THE COWLING. HE SAID EVERYTHING WAS BUTTONED UP; SO I RESTARTED THE #2 ENG FOR A 30 MIN GND RUN; AND COMPLETED THIS WITH NO PROB. I THEN SHUT DOWN AND WENT INSIDE TO RPT THAT THERE WAS NO PROB AND SEE IF THE ACFT WAS NOW AIRWORTHY. THE MECH SAID YES; SO I DECIDED TO FLY IT LOCALLY FOR 10 MINS TO BE SURE I WOULDN'T GET ANOTHER CHIP LIGHT BEFORE A COMMERCIAL FLT. AFTER TKOF AND ABOUT 5 MINS INTO THE FLT; MY #1 ENG N2 QUIT WORKING. I CALLED OUR RADIO MAN AND TOLD HIM TO INFORM MAINT. AS I WAS RETURNING TO THE ARPT I THEN GOT A BAGGAGE SMOKE WARNING LIGHT. I LANDED IMMEDIATELY; SHUT DOWN THE ENGS AND RAN BACK TO THE BAGGAGE COMPARTMENT. IT WAS FULL OF SMOKE BUT NO FIRE. SMOKE WAS COMING OUT OF THE RIGHT HAND ENG COMPARTMENT; BUT STILL NO FIRE; SO I WALKED AROUND TO THE LEFT HAND SIDE TO UNDO THE COWLING LATCHES. THE LEFT HAND COWLING LATCHES WERE NOT LATCHED AND THE SLIPSTREAM HAD FORCED THE COWLING OUT AND AFT. THIS RESULTED IN A MISALIGNMENT OF THE ENG EXHAUST AND THE COWLING EXHAUST PORT. BECAUSE OF THIS PART OF THE EXHAUST WAS BEING DEFLECTED BACK INSIDE ON THE ENGS. THIS EXHAUST MELTED MANY WIRES AND BURNED PAINT ON THE COWLING WHICH RESULTED IN THE SMOKE. I FAILED; AS A PLT; IN NOT RECHKING BOTH SIDES OF THE ENG COWLING; AS MY SIDE WAS LATCHED. AT THE TIME; IT SEEMED INCONCEIVABLE THAT A MECH WOULD ONLY LATCH HALF OF THE COWLING AND THEN TELL ME IT WAS COMPLETELY LATCHED.