FLC OF MLG RETURN TO LAND AFTER THE NOSE GEAR FAILED TO RETRACT AFTER TKOF DUE TO THE GND PIN STILL INSTALLED.

Narrative

I MET THE ACFT AT THE JETWAY AS THE MECHS TAXIED IT IN. AT THAT TIME I DID THE PRELIMINARY WALK-AROUND AND NOTED NOTHING UNUSUAL. THE FLT WAS BOARDED; WE DID HAVE A LAST MIN RE-RTE WHICH HAD TO BE PUT IN THE FMC BEFORE PUSH. A NORMAL PUSH; BOTH ENGS STARTED; WAVE-OFF BY PUSHBACK AND TAXI-OUT WAS ACCOMPLISHED. A NORMAL REDUCED PWR TKOF WAS ACCOMPLISHED AND GEAR RETRACTED AFTER LIFTOFF. THE 2 MAINS CAME UP NORMALLY; BUT THE NOSE GEAR RED AND GREEN INDICATOR LIGHTS WERE BOTH ON IN ADDITION TO THE NOISE ASSOCIATED WITH A NOSE GEAR EXTENDED. THE CAPT WAS FLYING. I TOLD DEP WE HAD A MINOR GEAR PROB. WE LEVELED AT 5000 AND STAYED ON VECTORS. I TOOK OUT THE PLT HANDBOOK BUT THERE WAS NOTHING IN THERE AND NO CIRCUIT BREAKERS OUT. WE TRIED TO RECYCLE THE GEAR ONCE WITH A GOOD DOWN AND LOCKED AS ALL BOGIES. UPON RAISING THE GEAR; THE NOSE GEAR STAYED DOWN AND LOCKED. WE BOTH THOUGHT IT MIGHT BE A NOSE GEAR PIN AT THIS TIME. I NOTIFIED COMPANY WE WERE RETURNING TO TPA WITH A NOSE GEAR PROB. THE CAPT FLEW A NORMAL ILS TO 18R NOTING THAT THIS WAS GOING TO BE AN OVERNIGHT LNDG AT APPROX 121000 LBS. A TOUCHDOWN OF LESS THAN 250 FPM WAS ACCOMPLISHED WITH A TAXI BACK TO THE GATE. THE NOSE GEAR PIN WAS FOUND IN NOSE GEAR AS THE PROB. MANY PEOPLE ARE CONTRIBUTING TO THIS INCIDENT. MY WALK AROUND FAILED TO NOTICE THE PIN INSERTED EVEN THOUGH I LOOKED IN THE WHEEL WELL. THE NEW MECH WHO LEFT THE PIN AFTER MAINT WAS PERFORMED OVERNIGHT. THE PUSHBACK CREW FOR NOT SEEING IT WHEN TAKING OUT THE WHEEL PIN. THE CAPT FOR NOT CHKING THE NUMBER OF GEAR PINS IN THE COCKPIT.