A BA3100 ON ENG START ROLLED FORWARD AND STRUCK A PARKED TUG INCURRING DAMAGE TO THE RADOME. CAUSE WAS THE FAILURE OF THE CAPT TO SET THE PARKING BRAKE.

Narrative

AFTER PULLING ACFT FROM THE HANGAR THE TUG WAS UNHOOKED AND MOVED INTO POS TO USE THE BUILT-IN GPU TO START THE ACFT. AFTER STARTING #2 ENG AND DOING THE CAPT FLOW; I LOOKED OUT THE WINDOW TO TELL THE GND PERSONNEL TO REMOVE THE GPU WHEN I NOTICED HIM WAVING AT ME TO STOP. I WAS GUARDING THE TOE BRAKES WITH MY FEET SO I APPLIED PRESSURE AND DID NOT FEEL ANYTHING. I REACHED DOWN AND PULLED ON THE HAND BRAKE AND IT CLICKED 1 MORE TIME TO THE FULL UP AND LOCKED POS AND STILL DID NOT FEEL THE ACFT MOVE OR STOP MOVING. WE SHUT THE #2 ENG DOWN AND GOT OFF THE AIRPLANE TO LOOK. THE AIRPLANE HAD ROLLED SLOWLY ABOUT 1 FT AND WAS LEANING AGAINST THE TUG. THE TUG WAS BACKED UP AND A SCRATCH ABOUT 4 INCHES LONG WAS NOTED ON THE NOSE CONE OF THE PLANE. MAINT LOOKED AT THE PLANE AND SAID TO BE ON THE SAFE SIDE THEY WOULD SEND IT TO THE REPAIR SHOP TO BE LOOKED AT AND IT WAS REPLACED WITH A NEW NOSE CONE. THERE WERE NO PAX OR BAGS ON THE PLANE AT THE TIME AND WE WERE IN THE PROCESS OF BRINGING THE PLANE FROM THE HANGAR TO THE GATE TO START OUR MORNING SHIFT. I FEEL A MAJOR CAUSE OF THE INCIDENT WAS THE CAPT NOT COMPLETELY SETTING THE PARKING BRAKE AND THE FACT IT WAS DARK WITH NO VISUAL REFS TO SEE THE PLANE ROLLING FORWARD.