MLG ACFT DAMAGED DURING RAMP OP PUSHBACK PROC.

Narrative

PREEXISTING CONDITIONS: APU GENERATOR INOP. ASKED GND PERSONNEL ON HEADSET IF WE COULD START AN ENG AT THE GATE ON GND PWR; OR PUSHBACK AND DO A BATTERY START. GND REQUESTED WE START #2 ENG AT THE GATE; THEN PUSH. BEFORE START; AND BEFORE PUSH/TAXI CHKLISTS COMPLETED. DURING START WITH BOTH HYD A PUMP SWITCHES OFF; THE A HYD SYS PRESSURIZED. INFORMED GND PERSONNEL THAT A HYD SYS HAD PRESSURIZED. ASKED IF THEY WERE ABLE TO BYPASS PRESSURE TO STEERING; OR SHUT DOWN ENG FOR THE PUSH. WAS TOLD THEY COULD BYPASS STEERING; OK TO PUSH. PUSHED STRAIGHT BACK FROM GATE; NO TURNS. BUMP WAS FELT AT START OF PUSH; WHICH IS COMMON AS TUG TAKES UP SLACK. AT END OF PUSHBACK; SET BRAKES; THEY DISCONNECTED TOW BAR AND HEADSET AS PER STANDARD OPERATING PROC. DEPARTED UNAWARE OF ANYTHING OTHER THAN COMPLETELY NORMAL OPS; AND FLT CONTINUED UNEVENTFULLY. AT ARR AT DEST; MAINT FOUND THE TOW PIN ON FRONT OF NOSE STRUT BROKEN. AFTER CONFERRING WITH MAINT; I FOUND THERE IS NO WAY TO BYPASS PRESSURE OR DISCONNECT THE STEERING ON THIS MODEL. OUR COMPANY HAS 3 DIFFERENT EARLY MODELS; AND 2 DIFFERENT LATE MODELS OF THIS ACFT. KEEPING TRACK OF DIFFERENT HANDLING PROCS REQUIRED FOR ALL THE ACFT AND VARIANTS IN OUR FLEET IS NOT EASY FOR OUR GND PERSONNEL; MANY OF WHICH ARE NOT PLTS OR MECHS. THE BOTTOM LINE IS I MUST KNOW MY ACFT'S SYS BETTER THAN ANYONE ELSE; AND NOT BE LED INTO A DANGEROUS SITUATION.