Date: 201401
Local time of day: 1801-2400
Location: ZZZZ.TRACON, FO
Flight conditions: VMC
Light: Daylight
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Climb
ATC / advisory: TRACON ZZZZ
Aircraft component: Squat Switch
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Critical
Detector: Automation Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Just after takeoff; the First Officer who was the non-flying pilot called positive rate. I called for gear up and immediately we received a Landing Gear Air/Gnd Fail message on the EICAS and the aural warning 'Takeoff Trim' message began sounding continuously. We continued climbing to 11;000 MSL and finished the after takeoff flow and checklist with the exception of leaving the Flaps at 9 to prevent the 'Takeoff Flaps' aural message from sounding. During the climb as an attempt to get the Takeoff Configuration aural warning to stop; I called for Gear Down. My thought was that if the Air/Ground Sensor failed; then by putting the gear down; I might be able to stop the Takeoff Configuration warning from sounding. That didn't work and in fact the gear lever could not be moved to the up position after it was selected DOWN. I then called for the Landing Gear Air/Gnd Fail QRH which directs us to the - Gear Lever Cannot Be Moved After Takeoff Checklist. We completed the checklist and per the QRH returned to the nearest suitable airport. The First Officer advised ATC of our intentions to return to the airport. The Flight Attendant was informed and we were vectored back to the airport and completed the In-Range; Approach; and Landing Checklists from the QRH. Made a smooth touchdown since our landing weight was 48;600 LBS. Upon landing we had no thrust reverse; however; with 13;000 FT of runway and normal braking; we were able to stop the airplane about halfway down the runway. We taxied back to the hardstand where the emergency authorities were waiting and we deplaned the aircraft. There were numerous threats on this flight to include: Language Barrier; Mountainous Terrain; and Difficulty Communicating with Aural Warning sounding; Overweight Aircraft; No Thrust Reverse after Landing. Each time an abnormal event occurs; I am truly in admiration of the professionalism exhibited by each of the crewmembers around me. Everyone from the First Officer running checklists and coordinating with ATC along with the Flight Attendant keeping everyone calm in the cabin made this air return seem almost routine. With the master warning bell and aural warning going off the entire time along with knowing the inherent dangers that surrounded us with the terrain; I sensed a little more urgency than normal in my own actions and overlooked the fact that I probably should have declared an emergency knowing that the thrust reverse; ground spoilers; and ground idle might not be selectable upon landing. Thankfully; the Tower had the fire trucks standing by although everything was uneventful. Definitely a lesson learned; when in doubt declare the emergency.




Synopsis: EMB-145 Captain experiences an Air/Gnd Fail message on the EICAS at takeoff as the gear is retracting. In an attempt to silence some of the many warnings the landing gear is extended to no avail then cannot be retracted. Flight returns to the departure airport for an overweight landing.