A CREW WAS DIRECTED TO FOLD THE JIB OUT ON AN 80 TON CRANE. THEY BEGAN TO PULL THE PINS ON THE STOWAWAY JIB WITHOUT INSTALLING THE HINGE PINS THAT PIVOT THE JIB OUT. AS A RESULT, THE JIB FELL OFF THE SUPPORT AND HIT THE EMPLOYEE ON THE WAY DOWN. IT CAME TO REST ON THE OUTRIGGER.