Date: 201205
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight phase: Landing
ATC / advisory: Tower ZZZ
Aircraft component: Squat Switch
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Critical; Ground Event / Encounter Loss Of Aircraft Control; Ground Excursion Runway
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Declared Emergency; General Maintenance Action
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: I reviewed the logbook and called Maintenance Control to speak about the previous 2 days write ups. I asked if the airplane needed a flight check regarding the LG AIR/GND FAIL and un-commanded swerving. Maintenance Control investigated the actions taken by Maintenance and said no flight checks were required and aircraft was in airworthy condition. After takeoff; received EICAS LG AIR/GND FAIL; E2 REV FAIL; E1-2 REV FAIL and complied with checklist. We declared an emergency with ATC and prepared cabin for emergency landing. We lowered landing gear and performed an approach to allow the Tower to view whether our gear was down. Tower confirmed gear down and we were vectored to land with flaps 45. The landing was smooth; on centerline; and not overweight. As the aircraft slowed down it became unresponsive and swerved towards the right and EICAS STEER INOP. Brakes were not working. The aircraft drifted onto grassy area and I had to pull the EM/PARK BRAKE to stop. The aircraft was surrounded by CFR. I made an announcement for cabin to remain calm and seated. I smelled smoke and called Flight Attendant who said she smelled smoke. I made announcement to evacuate and fire fighters were helping passengers evacuate but then they confirmed the aircraft was not on fire and they stopped the evacuation. The evacuation checklist was completed. Paramedics arrived and evaluated the passengers. Passenger service manager stated our unaccompanied minor was in his possession. No injuries reported. Paramedics evaluated the flight crew and no injuries reported. I made logbook entries regarding the EICAS messages.


Second narrative: Around 400-500 FT off the ground the LG AIR/GND FAIL message presented itself on the EICAS; followed by the E1-2 REV FAIL message. The decision was then made to return. I contacted ATC and stated the problem. We then declared an emergency and asked to make a low fly-by so that the Control Tower personnel could confirm that all three of the landing gear appeared to be down. After following the appropriate checklists we performed the fly-by. After flying by the Control Tower we were vectored for the visual approach. Captain performed a smooth landing followed by a normal/steady deceleration. Once slowed to approximately 20-30 KTS Captain stated that she couldn't keep the aircraft on the centerline and the brakes were not functioning. The aircraft was veering off to the right of the centerline; and eventually off the runway. Once I saw that Captain could not control the aircraft's direction; nor slow it down; I used brakes/differential brakes and left rudder to help prevent an excursion; which was also unsuccessful. The aircraft came to a halt on the paved surface; where CFR were ready to assist. The Captain and I smelled smoke or a burning smell of some sort and called the Flight Attendant right away to ask if she smelled smoke in the cabin. Flight Attendant confirmed that it smelled like something was burning and the evacuation was initiated by making the 'Easy Victor' PA. Evacuation checklist was performed. During the initial stages of the evacuation a fireman yelled that there was no smoke and to stop the evacuation. A ramp was then used by the Fire Department to deplane the remainder of the passengers; who were then escorted onto the bus and taken back to the terminal. The aircraft was powered by batteries until they had to be turned off due to low battery capacity.


Synopsis: EMB145 flight crew reports an EICAS LG AIR/GND FAIL message after selecting the landing gear up and elects to return to the departure airport. The aircraft had been previously written up for the same problem and repaired by Maintenance. During landing roll the brakes and nosewheel steering fail at low speed and the aircraft departs the runway before the parking brake can be applied. A partial evacuation ensues before it is deemed unnecessary.