NOSE GEAR STUCK ON AN ACR MDT ACFT RESULTING IN A NOSE GEAR UP LNDG.

Narrative

AFTER DEPARTING BOS AND COMPLETING AFTER TKOF CHKLIST CREW FOUND THAT THE GEAR IN TRANSIT LIGHT REMAINED FLASHING. THE 3 GREEN INDICATOR LIGHTS DID EXTINGUISH. CREW PERFORMED CHKLIST FOR SIT. CYCLED GEAR DOWN AND THE 3 GEAR LIGHTS ILLUMINATED BUT THE GEAR IN TRANSIT LIGHT REMAINED FLASHING. THE POH DOES NOT INCLUDE A CHKLIST FOR A SIT GEAR HANDLE DOWN AND THE GEAR IN TRANSIT LIGHT ON. CREW DECIDED TO CYCLE GEAR AGAIN. WHEN CREW SELECTED GEAR UP; THE 3 GREEN INDICATOR LIGHTS EXTINGUISHED AND GEAR IN TRANSIT LIGHT REMAINED FLASHING. WHEN GEAR WAS SELECTED DOWN THE MAIN GEAR INDICATORS LIGHTED BUT NOT THE NOSE WHEEL. GEAR WAS CYCLED 4 MORE TIMES. SIT REMAINED THE SAME; MAIN WHEEL INDICATORS LIGHTED BUT NOT NOSE WHEEL AND GEAR IN TRANSIT LIGHT REMAINED FLASHING. WHILE SIT WAS DEVELOPING; CREW WAS IN RADIO CONTACT WITH DISPATCH AND MAINT. CREW DECIDED TO USE EMER GEAR EXTENSION SYS. MAINT CONFIRMED THIS USE. THE EMER EXTENSION SYS DID NOT EXTEND NOSE GEAR. OUR DIRECTOR OF OPS ADVISED CREW TO DIVERT TO MHT (APPROX 25 MI AWAY FROM BOS). ACFT WAS LANDED IN MHT WITH NOSE WHEEL RETRACTED. NO PAXS OR CREW WAS HURT. CREW FOLLOWED ALL CHKLISTS WHICH WERE AVAILABLE. WHEN GEAR HANDLE WAS SELECTED DOWN AND GEAR IN TRANSIT LIGHT FLASHING; CREW HAD NO CHKLIST TO FOLLOW. CREW WORKED WITH MAINT DEPT TO DETERMINE COURSE OF ACTION AND CONTINUED TO CYCLE GEAR. MAINT CONFIRMED THAT WITH THE GEAR IN TRANSIT LIGHT FLASHING THAT WE HAD GEAR UNSAFE SIT. THE POH DOES NOT SUPPLY ENOUGH INFO CONCERNING THE SIT EXPERIENCED. A CHKLIST FOR GEAR HANDLE DOWN; GEAR IN TRANSIT LIGHT FLASHING WOULD HAVE AVOIDED ANY QUESTIONS ABOUT WHAT PROC TO TAKE.