A PA31 CPR PLT ATTEMPTED TO HOLD THE BRAKES WHILE WAITING FOR THE CONDENSATION ON THE WINDOWS TO CLR AS THE ENGS WARMED UP. THE ACFT CREPT FORWARD AND THE L WING STRUCK THE R WING OF AN HS25 CAUSING MINOR DAMAGE TO BOTH ACFT.

Narrative

AFTER BOARDING AND SERVING 5 PAX; I STARTED BOTH ENGS AND GOT MY IFR CLRNC. AS THE RESULT OF HIGH HUMIDITY (MODERATE RAIN) AND THE 6 PEOPLE ON BOARD; ALL THE RAINSTORMS ON THE ACFT FOGGED UP. I TURNED ON THE HEATER AND DEFROSTER. I PROCEEDED WITH MY CHKLIST WHILE WAITING FOR THE WINDSHIELD TO CLR. I THEN FELT A LIGHT JERK. LOOKING OUT; I SAW THAT MY L WING WAS TOUCHING THE R WING OF A CPR JET. MY FIRST THOUGHT WAS THAT THE OTHER ACFT HAD HIT ME AS I WAS STANDING STILL. THE R SEAT PAX THEN INFORMED ME THAT MY ACFT HAD BEEN CREEPING FORWARD AND CAME IN CONTACT WITH THE OTHER ACFT. MY FEET WERE ON THE BRAKE; BUT I MUST HAVE RELAXED THE PRESSURE WITHOUT REALIZING IT ALLOWING MY ACFT TO MOVE FORWARD. BECAUSE OF THE FOGGY WINDOWS; THE RAIN AND THE DARKNESS; I DIDN'T HAVE ANY VISUAL CLUES THAT I WAS MOVING. MY ACFT HAD MOVED ABOUT 50 FT BEFORE CONTACTING THE OTHER ACFT (#2). THE DAMAGE TO MY ACFT WAS MINIMAL: A SMALL TEAR IN THE DEICING BOOT AND A 4 INCH SCRATCH ON TOP OF THE LEADING EDGE. PRELIMINARY INSPECTION OF THE ONLY ACFT (#2) SHOWS THE ONLY DAMAGE TO BE A TORN-OFF STATIC WICK ON THE R AILERON. THIS INCIDENT WAS CAUSED BY MY FAILURE TO PROPERLY SET THE HAND BRAKE PRIOR TO STARTING THE ENGS. CONTRIBUTING FACTORS WERE RAIN; DARKNESS; CONDENSATION AND FOG INSIDE THE ACFT AND TO A SMALL EXTENT TIREDNESS. AT THE TIME OF THE INCIDENT I HAD BEEN UP FOR OVER 15 HRS AND ON DUTY FOR 8 HRS. I LEARNED A VALUABLE LESSON: I WILL NEVER EVER START AN ACFT ENG UNTIL I ASSURE THAT THE HAND BRAKE IS SET PROPERLY AND LEAVE IT SET UNTIL READY TO TAXI OUT.