AN EMBRAER 145 IN CLB AT 10000 FT HAD EICAS MESSAGE 'LNDG GEAR AIR-GND FAIL.' DECLARED AN EMER AND CONTINUED TO SCHEDULED TRIP TERMINATION. FOUND FAILED GEAR PROX SWITCH.

Narrative

AFTER TKOF; AN EICAS MESSAGE APPEARED 'LNDG GEAR AIR/GND FAIL' AND SHORTLY AFTER THAT; AN 'ENG 1-2 REVERSER DISAGREEMENT' MESSAGE APPEARED. AS THE ACFT WAS CONFIGURED FOR CLB AND HANDLING NORMALLY; THE QRH'S AND AFTER TKOF CHKLISTS WERE COMPLETED. THE FO AND I DISCUSSED THE PROB AND THEN CONTACTED COMPANY DISPATCH IN ZZZ. WE WERE HANDED OVER TO MAINT CTL WHERE WE DISCUSSED A PROX SWITCH PROB AND THE MESSAGES ON THE EICAS. A DECISION WAS MADE TO CONTINUE FOR ZZZ AND THE CRUISE PORTION OF THE FL UNEVENTFUL. THE EICAS MESSAGES REMAINED ON THE SCREEN. DURING THE DSCNT INTO ZZZ; THE FO APPLIED SPD BRAKES BUT NOTHING DEPLOYED AND A DISAGREEMENT MESSAGE APPEARED. AT THIS POINT; WE BRIEFED THE PROPER QRH'S FOR A LOSS OF BRAKES; STEERING; REVERSERS; AND SPOILERS FOR OUR LNDG. I TESTED THE FLT ATTENDANT IN THE COCKPIT AND MADE AN ANNOUNCEMENT TO THE PAX TELLING THEM OF THE SIT. I ALSO INFORMED COMPANY OPS OF OUR DECLARED EMER. WHEN I CHKED ON WITH ZZZ APCH; AN EMER WAS DECLARED; A REQUEST FOR RWY 15L MADE (LONG RWY AND PREVAILING WIND) AND ARFF EQUIP STANDING BY FOR A POSSIBLE LOSS OF STEERING AND BRAKING UPON LNDG. THE EICAS MESSAGES STILL APPEARED. DURING THE APCH PHASE; BOTH EICAS MESSAGES REMAINED ON THE SCREEN. AT 400 FT; ABOVE TOUCHDOWN; THE EICAS MESSAGES CLRED THE SCREEN AND A NORMAL LNDG WAS MADE WITH NO CTL DIFFICULTIES ON THE RWY. I STEERED THE ACFT OFF THE RWY; STOPPED; AND THE FO RAN THE AFTER LNDG CHKLIST WHILE I CONSULTED WITH GND CTL AND THE FLT ATTENDANT. WE TAXIED TO THE GATE WITHOUT FURTHER INCIDENT AND A MAINT WRITE-UP WAS LOGGED IN THE LOGBOOK. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE LNDG GEAR GND SHIFT CIRCUIT FAILED IN THE GND MODE AND WAS CAUSED BY A MAIN LNDG GEAR PROX SENSOR.