CE560 FLT CREW REMOVES NOSEWHEEL SCISSORS PIN FOR TOW IN TO PARKING THEN FORGETS TO REINSTALL PRIOR TO TAXI. WHEN OMISSION IS DISCOVERED ACFT IS STOPPED ON TXWY AND CAPTAIN RUNS OUT TO REINSTALL THE PIN.

Narrative

FO WAS AT THE CTLS DURING TAXI; DURING RUDDER BIAS CHK (WE) NOTICED A NOSE SHIMMY. IMMEDIATELY WE STOPPED ON THE TXWY AND THE CAPT WAS GETTING OUT OF HIS SEAT; AS WE BELIEVED THE SHIMMY TO BE AN UNATTACHED STEERING PIN. (THE ACFT WAS TOWED ABOUT 45 MINS PRIOR TO TAXI.) AT THAT TIME I INFORMED GND THAT WE HAD AN INDICATION TO CHK. DURING THE CONVERSATION; THE CAPT HAD OPENED THE DOOR TO EXIT THE ACFT TO CHK OR REATTACH THE STEERING PIN. AT THAT TIME THE GND ATC SAID; 'NO ONE MAY EXIT THE ACFT.' I YELLED OUT TO THE CAPT TO RELAY THIS INFO; BUT HE WAS HALF WAY OUT THE DOOR. THE ENGS WERE RUNNING SO THERE WAS 'NO WAY' HE COULD HAVE HEARD ME. I REMAINED AT THE CTLS WITH THE PARK BRAKE ON. THE CAPT RETURNED TO STATION AND ATC WANTED PLT INFO AND INSTRUCTED THE PIC TO CALL HPN UPON LNDG AT DEST. NORMAL TAXI AND TKOF WAS PERFORMED. THERE WAS NO DANGER TO ANY PERSONS OR PROPERTY DURING THE EVENT; WHICH WAS ABOUT 45 SECONDS. UPON REACHING DEST; THE CAPT CALLED HPN AND HAD A DISCUSSION. ALL WAS UNDERSTOOD AND HPN DROPPED ANY PENDING FAA CONSULTATIONS.