Date: 201908
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
Airspace: Class C ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Aircraft component: Squat Switch
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Confusion; Workload; Troubleshooting
Anomaly: Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Fuel Issue
Detector: Automation Aircraft Other Automation
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Overcame Equipment Problem; Flight Crew Returned To Departure Airport; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Departing Runway XX at ZZZ; right at rotation; there was a master caution and EICAS message for LG AIR/GND FAIL. I have seen this happen before; so I initially wasn't concerned; sometimes it's a brief nuisance message. I was PM (Pilot Monitoring); so I called 'Positive Rate' and my FO (First Officer) responded 'Gear Up'. At this point; I realized that the landing gear lever wouldn't move. I told my FO to just fly the airplane; keep the speed below 200. I tried the lever multiple times in short order; but it would not move. I informed ZZZ Tower of what was going on and took the handoff to [TRACON]. [TRACON] asked what I wanted and I said delay vectors to run the QRH checklist. The checklist was limited in scope and since the weather was good; the FO and I agreed to return to ZZZ. I checked the weight and realized we were over max landing weight. The airplane was flying well; so we agreed to burn off fuel and return below MLDW (Maximum Landing Weight).[TRACON] was helpful in giving us vectors. I informed the FA (Flight Attendant) of what was going on and told her to prepare for a normal landing and made an announcement to the passengers. I called Operations and I sent Dispatch an ACARS text to inform them of what was occurring. I was asked if I could divert the airplane to ZZZ1 instead of a ZZZ return. I briefly considered it; even when I first realized the issue; knowing it would be better for the passengers and the company. That's when the first aural warning for 'Takeoff-Trim' occurred. The message repeated 5 times and went away. Then an EICAS message for EMER LT NOT ARMED and IC 1-2 WOW INOP appeared. We kept getting intermittent 'Takeoff-Trim' configuration warnings the entire time. I was not certain what was going to happen and we decided it was in the best interest to get on the ground as quick as we could once below max landing weight. At this time; I [advise ATC]; because I wanted CFR (Crash Fire Rescue) waiting in case anything went wrong. The QRH checklist mentions that you might not have thrust reversers; steering or brakes; I wanted to prepare for the worst; even though anything serious during landing was remote; but the extra EICAS messages caused me concern about what the plane might do when back on the ground.We were vectored for the ILS Runway XX at ZZZ and the FO made a nice gentle landing. As we rolled out; he remarked that he didn't have thrust reversers. We exchanged the controls and I confirmed that they weren't working. I gently tried the nose steering with the tiller as we slowed; it was fine. Applying the brakes; they felt weak; but they would slow the airplane. I rolled to the end; assessing that I had brakes and steering. We agreed to taxi to the gate with the CFR vehicles following us. Halfway to the gate; the SPS (Stall Protection System) triggered and would not stop until I pushed both console cutout switches.We pulled into Gate XX in ZZZ without further incident. In hindsight; I should have asked for another gate because XX in ZZZ is extremely tight and the warning in the QRH about brakes below 10 kts. gave me pause. I gingerly made my way into the gate; assessing my brakes and steering the whole time. As they deplaned; the passengers were angry about their connections and their flight being interrupted. The Gate Agent later told my FA a few passengers said that we hadn't told them anything; which wasn't true in the least; as I made multiple PA's as did my FA. We waited for another aircraft to ferry into ZZZ and took the remaining passengers to ZZZ1. My crew and I decided we were not fit to continue the rest of our flying day and overnighted in ZZZ1. The situation went as well as could be expected. More guidance from the QRH would have been nice; but the LGEU (Landing Gear Extension Unit) and associated parts have so many variables that not much can be done from the cockpit. Operations knew we were returning to the field/gate and they didn't have the gate area setup; nor were they waiting for us. There were no other flights on the ground at the time. Waiting for a gate in this situation is not acceptable.




Synopsis: EMB145 flight crew reported a problem with weight on wheels sensor; prompting a return to the departure airport.