ACR STRIKES GPU WHEN BEGIN TAXI FROM GATE.

Narrative

SITUATION: APU-MEL. USED A GPU FOR ENG START. AFTER USING NORMAL PROCS TO START THE ENGS THE CAPT SIGNALLED FOR GPU DISCONNECT AND CALLED FOR THE AFTER START CHKLIST. AFTER ACCOMPLISHING THE CHKLIST; I CHKED THE EXTERNAL PWR CONNECT LIGHT AND IT WAS OUT. I ASKED IF HE WAS READY FOR TAXI AND HE ACKNOWLEDGED 'YES.' I CALLED FOR TAXI AND CLRED TO THE R BUT COULD NOT SEE THE GPU TRUCK AS LIHUE PARKS IT VERY CLOSE TO THE R FRONT OF THE ACFT. GND CTL RESPONDED WITH A TAXI CLRNC AND THE CAPT STARTED TO TAXI. A FEW SECONDS LATER WE FELT THE ACFT CONTACT THE GPU TRUCK. WE DEPLANED THE PAXS AND SHUT DOWN BOTH ENGS. THE ACFT HAD MINIMAL DAMAGE. THE GPU TRUCK HAD DAMAGE TO THE TRUCK CAB ABOVE AND AFT OF THE DRIVER'S DOOR. THE R REAR TIRE WAS FLAT BUT THERE WAS NO DAMAGE TO THE GPU UNIT AND AFTER A TIRE CHANGE THE TRUCK DROVE AWAY NORMALLY. IT WAS THE END OF A LONG; HOT DAY. WE HAD NO APU AND THIS WAS OUR LAST FLT OF THE DAY. SO THE MARSHALLER RUNS OVER AND HELPS THE GPU PERSON AND LEAVES NO ONE IN VIEW OF THE CAPT. THE GPU TRUCK IS PARKED VERY CLOSE TO THE R FRONT OF THE ACFT TO MAKE IT EASY FOR THE TUG AND BAGGAGE CARTS TO LINE UP WITH THE FORWARD BELT LOADER; IT CAN'T BE SEEN FROM THE COCKPIT. THE MARSHALLER USED NON-STANDARD HAND SIGNALS WHERE BY THE CAPT THOUGHT ALL WAS CLR AND STARTED HIS TAXI. TO PREVENT ANY FURTHER RECURRENCES I WOULD RECOMMEND THE USE OF A HEADSET BTWN THE MARSHALLER AND THE COCKPIT FOR THE ENG START; ESPECIALLY WITHOUT THE APU OPERATIONAL AT ALL TIMES. PARKING THE GPU OUT FRONT IN CLR VIEW OF THE COCKPIT. STANDARDIZING HAND SIGNALS.