Date: 201701
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: IMC
Aircraft: EMB ERJ 190/195 ER/LR
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Descent
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Aircraft component: Navigational Equipment and Processing
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Overcame Equipment Problem; Flight Crew Landed in Emergency Condition; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Took off and encountered a MAU [Modular avionics unit] 3A Failure at cruise in IMC about 8 minutes prior to top of  descent. The F/O was the pilot flying when the failure occurred. Initial indication of the failure was of the A/P failing (Aural Warning; Master warning; EICAS MSG); failure of the autothrust (aural warning; master caution; EICAS MSG) and flight director failure. We received the stick shaker anticipated master caution and EICAS (due to failure) while at 290 KIAS followed by FMS POS and GPS 2 on MCDU 2 with associated indications of position failure/FMS2 failure on the MFD2. We also lost ACARS initially with a datalink no com message in the scratchpad. The EICAS message MAU 3A Fail EICAS was also present and eventually the root cause for the multiple failures. Having had a similar failure last week and knowing the implications; I advised ATC and had the F/O continue to fly an assigned heading and altitude. Weather was last reported; prior to TOD; 1/4sm. We were luckily set up and briefed for the arrival and approach prior to failure. I was actually on the inter phone with the F/A1 when the failures occurred to brief her on the autoland procedures due to the low visibility. Seeing that the weather was below CAT 1 initially; we needed more time to think and come up with a plan. We slowed down to 250 to increase time (task loading) and save fuel. After running the QRH; we were able to better  analyze the situation and what was permanently failed and what we got back. We communicated very well and hats off the F/O for his ability to fly; talk on the radio and stay engaged. We switched the FMGC source to CAPT and were able to regain the auto pilot channel 1 and autothrust channel 1. I was able to finally get through ARINC to dispatch to come up with a plan. ATC was able to issue an updated special weather report with ceiling and vis above CAT1 and the dispatcher and I agreed to continue to with plan B being a diversion to ZZZ1. Emergency vehicles were asked to standby and we landed safely. Flight attendants were briefed on the failure with 20 minutes to land with a normal landing anticipated. The passengers were given the same information and a heads up of the emergency vehicles standing by as a precaution. We arrived at our assigned gate and maintenance promptly met the aircraft. Failure of AVNX MAU 3A. With this failure being the second I have had in one week and the severity of complications potential from this failure; I would suggest a flight bulletin and/or increased training on this type of failure.


Second narrative: [Report narrative contained no additional information.]


Synopsis: EMB190 flight crew reported a modular avionics unit failure that affected avionics on the First Officer's side. The Captain stated it was the second MAU 3a failure he had experienced in one week.