Date: 201912
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight phase: Parked
Aircraft component: Autoflight System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Communication Breakdown
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Aircraft In Service At Gate
Result: General Maintenance Action
Contributing factors: Aircraft; MEL; Manuals; Procedure
Primary problem: MEL

Narrative: I was Captain on the ZZZ - ZZZ1 flight. When I looked at the release; I saw there were a lot of MELs and restrictions that pertained to inoperative automation. I also saw that we had a standardization check on this airplane. Typing the root cause MEL number into the search feature of the MEL manual; I immediately went over the MELs with the FO (First Officer) to get a picture of what we were up against. There were several MELs as the result of 22-XX-XX-X Guidance Panel MEL. I briefed alternate procedures as per the MEL and also determined the weather in ZZZ1 was good. As there was a higher altitude than standard for activating and disconnecting the autopilot; the approach had to be flown with the autopilot off as per MEL.The aircraft was late being towed up to the gate; which put us under time pressure. When I got into the flight deck; I noticed AP FAIL and AT FAIL EICAS messages; which concerned me and prompted me to call Maintenance. I started off by saying [that] I had read the MELs and understood them; but I wanted to know what was going on with the AP FAIL and the AT FAIL messages and if they and the other EICAS messages were associated with the MELs. Maintenance said inoperative items were a result of the Guidance Panel MEL. I was assured the aircraft was fine; but insisted again that I wanted to make sure that the autopilot and autothrottle would function in flight. Maintenance read the MEL and said it was clear as mud and the aircraft was fine- it had been flying around for 8 days in this condition.During all of this; the FO said his buttons were not functioning; to which I responded; well we found the non-operative side; I guess it's my leg. At that point; I moved on to solving the other problem; which was our missing Check Airman; and getting the flight off the gate as soon as possible. I was informed the Check Airman's schedule had been changed and we pushed back and flew to ZZZ1. When I got to the hotel in ZZZ1; I asked a friend for guidance. He said that one of the EICAS messages; AFCS PANEL FAIL; was a no dispatch item; and the airplane had been incorrectly MEL'd. He said Maintenance had MEL'd the airplane for an AFCS FAULT instead.




Synopsis: EMB-175 Captain reported a misapplication of an MEL which resulted in the aircraft flying in a non airworthy condition.