AN EMB120 IMMEDIATELY AFTER TKOF DECLARED AN EMER AND DIVERTED DUE TO THE R MAIN GEAR UNSAFE LIGHT ON WITH THE GEAR HANDLE UP CAUSED BY THE UPLOCK HOOK OUT OF ADJUSTMENT.

Narrative

ACFT RETURNED TO GATE AFTER R GEAR INTRANSIT LIGHT. EMER EQUIP DISPATCHED EVEN THOUGH 3 GREEN INDICATION. THE PROB WAS WITH THE GEAR HANDLE UP (R INTRANSIT). THE UPLOCK HOOK NEEDED TO BE ADJUSTED. A STEP THAT WAS MISSED DURING A LNDG GEAR CHANGE THE NIGHT BEFORE. THE STEP WAS OVERLOOKED AND COULD HAVE BEEN PREVENTED BY A MORE SUBSTANTIAL TURNOVER BTWN SHIFTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THAT THIS TYPE OF FAULT OCCURS OCCASIONALLY WHERE THE MAIN GEAR IS REPLACED AND THE HOOK IS ADJUSTED BUT IN THE AIR WILL GET THE GEAR UNSAFE LIGHT. THE RPTR SAID IT MAY BE CAUSED BY THE AIR LOADS ON THE WING AND LNDG GEAR MOVING THE GEAR OR HOOK OUT OF ADJUSTMENT AND IF THIS IS THE CASE THE MAINT MANUAL SHOULD BE REVISED TO ALLOW GREATER ADJUSTMENT LIMITS. THE RPTR STATED ON THIS ACFT THE GEAR WAS SWUNG 10 TIMES AFTER REPLACEMENT AND TESTED GOOD EVERY CYCLE. THE RPTR SAID WHEN THE ACFT RETURNED THE HOOK ADJUSTMENT REQUIRED WAS A FEW THOUSANTHS OF AN INCH. THE RPTR SAID THE FAA HAS MADE CONTACT.