Narrative:

After takeoff, an EICAS message appeared 'landing gear air/ground fail' and shortly after that, an 'engine 1-2 reverser disagreement' message appeared. As the aircraft was configured for climb and handling normally, the QRH's and after takeoff checklists were completed. The first officer and I discussed the problem and then contacted company dispatch in ZZZ. We were handed over to maintenance control where we discussed a proximity switch problem 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 descent into ZZZ, the first officer applied speed 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 landing. I tested the flight attendant in the cockpit and made an announcement to the passenger telling them of the situation. I also informed company operations of our declared emergency. When I checked on with ZZZ approach, an emergency was declared, a request for runway 15L made (long runway and prevailing wind) and arff equipment standing by for a possible loss of steering and braking upon landing. The EICAS messages still appeared. During the approach phase, both EICAS messages remained on the screen. At 400 ft, above touchdown, the EICAS messages cleared the screen and a normal landing was made with no control difficulties on the runway. I steered the aircraft off the runway, stopped, and the first officer ran the after landing checklist while I consulted with ground control and the flight attendant. We taxied to the gate without further incident and a maintenance write-up was logged in the logbook. Callback conversation with reporter revealed the following information: the reporter stated the landing gear ground shift circuit failed in the ground mode and was caused by a main landing gear proximity sensor.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.