LTT ATX MOVES FORWARD DURING ENG START AND HITS APU CART.

Narrative

WHILE STARTING ENGS; PARKING BRAKE DID NOT HOLD ALLOWING ACFT TO CREEP FORWARD; CAUSING DAMAGE TO ACFT AND GND PWR UNIT; AS FOLLOWS: MY COPLT AND I HAD BEEN ON DUTY FOR ABOUT 7 HRS. WE HAD FLOWN INTO IND -- ABOUT A 1 1/2 HR FLT -- ARRIVED AT ABOUT AM00 EST. THE TEMP WAS ABOUT 25 DEGS F. THE ENGS (AND CREW) WERE COLD AND DIFFICULT TO START. THE BEFORE START CHKLIST WAS RUN THAT CALLED FOR 'BRAKES SET.' THE GND CREWMAN CALLED TO START ENG. I CUSTOMARILY START THE #2 ENG FIRST; SINCE IT GIVES BETTER CTL IN THE COCKPIT. THE ENG STARTED; RUNNING ROUGH; AS USUAL AS IT HEATED UP. I THEN SIGNALED FOR THE GND PWR UNIT TO BE REMOVED. I PERCEIVED THAT THE APU HAD BEEN REMOVED TO A SAFE DISTANCE -- HOWEVER; IT HAD BEEN DISCONNECTED IN PLACE; IN FRONT OF THE R ENG. NOTE: THE GPU IS NOT VISIBLE BY THE CAPT. MY COPLT WAS RUNNING THE AFTER START CHKLIST FOR THE R ENG AND WATCHING THE ENG INSTS FOR A VERY SLOW OIL PRESSURE RISE. I WAS SIGNALED BY A MECH OUTSIDE TO START THE L ENG. I WAS VERY BUSY TRYING TO START THE COLD ENG; SWITCHING MAGNETOS ON; JUST THE R PRIME AND JUST AS THE L ENG BEGAN TO TRY TO START; I HEARD THE BANG THE ACFT HAD CREPT FORWARD AND THE R PROP STRUCK THE APU. I THOUGHT THERE HAD BEEN AN EXPLOSION AND SHUT DOWN THE ENGS AND PWR. CONTRIBUTING FACTORS: COLD TEMP; RUSH BY CUSTOMER POOR LIGHTING ON THE RAMP; WRONG PLACEMENT OF APU; BOTH CREWMEMBERS CONCENTRATING ON THE TASK AT HAND. CORRECTIVE ACTION: APU NOW PLACED REAR AND R OF ACFT. COPLT HOLDS BRAKES DURING STARTING OP (NOTE CAPT SETS BRAKES; COPLT CANNOT UNSET FROM HIS SIDE. BETTER LIGHTING HAS BEEN REQUESTED).