CE-750 flight crew reported multiple system and display failures; electrical smoke smell and limited control; resulting in a priority handling return to departure airport.
Synopsis
CE-750 flight crew reported multiple system and display failures; electrical smoke smell and limited control; resulting in a priority handling return to departure airport.
Narrative
Upon departure airport Wx was VFR; then we were IMC during half the climb; and during the decent back into ZZZ IMC till about 600' AGL then it was 10 miles vis underneath.During climb below FL350; I as pilot not flying decided to go back and help the pax with their catering. We were not in critical phase of flight and I was next to the cockpit. Not long after I got back there I heard the CAS message alert system going off with multiple CAS messages. I drop what I was doing immediately and got back in my seat. As I was transitioning into my seat I advised pilot flying to [request priority handling] with ATC. After I got seated with seat belt fastened; we had DU (display unit) 1; 2; and 3 plus FMS (flight management system)/RMU (radio management unit) 1 blank out also loss of FGC (flight guidance computer); I took controls from FO (First Officer) and flew for a few mins till we got things under control. Durning that time we briefly had a smell of electrical smoke due to multiple circuit breaks tripping; so we advised ATC that we needed to divert back to ZZZ. No other indications of fire or smoke after that. ATC got us vectoring back towards ZZZ. We decided because we had DU 4; and 5 with good indications to have the FO fly again; I transferred controls back to him and started to help him with non pilot flying (as we had no Autopilot) and set up the plane for the return back into ZZZ. Due to the hectic things going on and me helping FO with setting things up and short amount of flight time back we decided to forgo the [priority] checklist and normal checklist. As we were heading back in we queried ATC about weather at ZZZ1 and ZZZ; they told us that weather at ZZZ1 was IFR and vis was not that great; they did say that ZZZ was IFR but better VIS. So we opted to go into ZZZ. We were IMC most of the way back in. We did try to do a little bit of trouble shooting (EICAS reversion and DAU (data acquisition unit) reversion cause we had missing info on FO side DU; also tried to close cross tie) none of the things works. We also found the neither electrical trims (primary and secondary) worked. As we were in the approach to XXR we found the flaps didn't work. We didn't have time to run the no flap landing checklist as we were capturing the approach and about to land. We knew that ZZZ had a long enough runway to land with no flap high speed trim; overweight landing. We went off the white arc on the AOA from (FO PFD (primary flight display)) for landing; we touch down around the 500 ft. to 1000 ft. markers and used full thrust reversers and got on the brakes max with in moments of touch down; I helped get the nose on the ground and FO got the speed brakes out. We got the plane slowed down enough that we were able to exit the runway onto Taxiway 1. Tower did ask if we were going to shut down on the runway or exit; initially we did say we were going to shut down on runway; but once we felt to that we were slow enough that we could exit and shut down on the taxiway. We did a [priority] shut down and exit. Cause: Not sure [of the cause]; some electrical issue with the plane. we did see 4 circuit breaker popped.Suggestion: [I suggest] proper maintenance.
Second reporter narrative
Upon departure the airports weather was VFR; Upon Arrival the conditions worsened and the field went IFR. The winds were light and down the runway; when we got under the 600' ceiling the visibility was 10SM+.During the climb phase; we briefly leveled off at FL350 and Pilot Monitoring (Captain) went back to help the passengers with their catering. At this time; it was not a critical phase of flight; it was a non-task saturated time; and he stayed right next to the flight deck at the galley the whole time. While he was up; multiple amber CAS messages illuminated and we assessed the situation and decided to [request priority handling]. Captain immediately got back to the left seat and took the controls; as that happened the DU's (Display Units) #1;2;3; FMS (Flight Management System) #1; RMU (Radio Management Unit) #1; all went black; we lost Autopilot; and our electric trim failed. During this time; multiple circuit breakers popped and we briefly smelled a burning smell from those breakers popping. There were no further indications of a fire or any smoke. Directly after [requesting priority handling]; we requested Vectors and Altitudes back to ZZZ Airport to attempt an approach back to the runway we just took off from. Captain had the controls for the first few minutes getting us turned around and descended to a lower altitude. When we determined it would be easier for me to fly given that DU's 4 and 5 were still operational; I took the controls for the remainder of the flight. After we got oriented with what the issues were; we began to troubleshoot the different problems. Firstly; we unsuccessfully tried to revert the EICAS to DU4 resulting in a X across the whole screen. We also lost the ability to set things like headings and altitudes so we attempted to do a DAU (Data Acquisition Unit) reversion with no success. With the cascading failures; IMC conditions; lack of Autopilot; and no EICAS to further diagnose specific problems; we both had our attention on aviating; navigating; and communicating and did not complete any further [priority] or normal checklist. At this point; we are headed back to ZZZ and are reviewing different options we have for airports; the two primary we discussed were ZZZ and ZZZ1. We requested ATC to give us weather updates for both airports. Both airports at the time had changed to IFR weather; ZZZ seemed to only have the lower ceilings; while ZZZ1 was reporting low ceilings; 3SM visibility; and that it had started to snow. We chose ZZZ to divert to firstly because that was what was originally planned during our departure brief; the weather was better then ZZZ1; it had a sufficiently long (10;001 ft. runway); and we were familiar with the airfield. After we made the decision to return back to ZZZ; we set up the approach in the FMS; got our IPAD's loaded with moving maps of the approach plates to show our location in relation to the approach as a back up; and were fully set up for arrival into ZZZ. When setting up for the approach back into XXR we attempted to deploy flaps and they were also inoperative at the time. Given the fact that we were only 12 to 15 miles from the airport; we did not have time to run the no flaps approach checklist and referred to white arch on the speed tape as a reference for speeds. On the Approach with our landing gear down; the speed at the top of the white arch was approximately 195kts. With being overweight and not having slats or flaps we touched down between the 500 ft. and 1000 ft. markers at 195 kts.; rapidly deployed the speed brakes; Thrust Reversers; and performed max braking. We got the plane stopped by Taxiway 1 and had enough control over the aircraft to exit the runway and stop on the 1 [taxiway]. We quickly shut everything down; set the parking brakes; and evacuated the passengers and crew instructing them to safely stay together and stand away from the plane in the grass while Operations and Firefighters were standing by to assist.Cause: Some electric failure that shut down everything on the left side of the aircraft; electric trim; and Flaps.Suggestion: [I suggest] proper maintenance.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.