GV FLT CREW FAILS TO REMOVE LNDG GEAR PINS PRIOR TO FLT RESULTING IN LOSS OF NOSEWHEEL STEERING UPON LNDG.

Narrative

PRIOR TO DEP FROM TTN; NJ; I FAILED TO NOTICE THE LNDG GEAR PINS HAD NOT BEEN REMOVED. AFTER TKOF; LNDG GEAR OF COURSE FAILED TO RETRACT. I REALIZED THE GEAR PINS WERE STILL IN; SO I SELECTED LNDG GEAR HANDLE DOWN AND CONTINUED TO HPN IN VFR CONDITIONS. I PLANNED TO REMOVE THE PINS AFTER LNDG AND CONTINUE THE PAX PORTION OF THE TRIP. UPON LNDG THE NOSEWHEEL STEERING WOULD NOT WORK NECESSITATING WE STOP ON THE RWY AND AWAIT A TOW TO THE FBO. THIS STOPPED OPS AT HPN FOR ABOUT 30 MINS. ONCE AT THE FBO; WE CONTACTED THE NE GULFSTREAM TECHNICAL REPRESENTATIVE WHO INFORMED US WE WOULD NEED TO JACK THE ACFT AND COMPLETE A LNDG GEAR RETRACTION CYCLE TO RE-SEQUENCE THE LNDG GEAR SYS. THIS WAS ACCOMPLISHED AND THE LNG GEAR AND NOSEWHEEL STEERING RETURNED TO NORMAL. WHILE THE ACFT WAS ON JACKS; GULFSTREAM CALLED BACK TO TELL US THERE WOULD BE NO NEED FOR THE GEAR SWING; WE COULD JUST PUSH THE 'LNDG GEAR RESET V' SWITCH IN THE COCKPIT OVERHEAD PANEL. THIS WOULD HAVE ALSO RESET THE SYS INFLT AVOIDING THE LNDG WITH INOP NOSEWHEEL STEERING. THE PROB WAS CAUSED BY MY RELIANCE ON MAINT TO ALWAYS PULL AND STOW THE PINS AND OF COURSE MY FAILURE TO NOTICE THEY HAD NOT. OUR NEW PROC IS ONLY THE CAPT IS ALLOWED TO STOW THE PINS; WHOEVER REMOVES THEM MUST PLACE THE PINS ON THE AIRSTAIR STEPS; SO THE CAPT CAN STOW THEM.