Caravan Undifferentiated
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Provided Assistance; Flight Crew Became Reoriented; Flight Crew Landed As Precaution; Flight Crew Overcame Equipment Problem; General Maintenance Action; General Flight Cancelled / Delayed
Aircraft; Equipment / Tooling
Just after completing a climb to 12;000 ft in an attempt to get above an icing layer; the company issued iPad mount fell off the windscreen on to the floor. Initially; I reacted to this by reaching down to pick it up; but simultaneously noticed the G600 displayed a GPS failure indication on the moving map side of the screen. At the same time TAWS (terrain awareness and warning system) gave an aural alert 'TAWS NOT AVAILABLE'. There were no additional audible alerts or visual annunciations. I initially thought this was simply a GPS signal failure and was starting to react accordingly; I then observed that the aircraft had entered a descending turn and immediately reacted with an unusual attitude in IMC recovery procedure. Given that the aircraft was in continuous light turbulence; in the clouds; at night; I was momentarily completely focused on ensuring the aircraft remained in a controlled attitude. A few moments latter I began taking stock of what I did and did not have. I observed the GMX200 screen off; GNS530 screen off; the primary GTX330 was off; and the autopilot was off. The G600 was giving associated GPS/AHRS and GAD43 failures. There were no other annunciations on the primary panel; and no audible alerts. My next focus was to re-establish navigation to my next known waypoint; the ZZZ VOR. I had previously tuned the ZZZ VOR into the NAV1 and NAV2; so I had manual navigation and DME via NAV2. Since the GNS430 and secondary GTX330 appeared operable; I immediately squawked 7600 as I had been out of contact with ZZZ1 Center (which was on COM1) and had obviously deviated heading/altitude at the beginning of the incident a few moments earlier. Not knowing what was happening to cause these failures and what might be failing next; setting the squawk may at the very least alert Center that I am having a problem. I also needed a few moments to sort out which frequency I needed to be on; as at this point the stress level was high enough I could not remember the frequency. I had to retrieve the iPad which was still on the floor in order to look at the chart screen for the frequency. Once back in contact with ZZZ1 Center I described the situation as best I could: some kind of electrical and/or communication failure as most of my avionics were now off. I elected for a diversion to ZZZ; now about 17nm away; and worry about troubleshooting the problem on the ground rather in the air in IMC at night. I was given vectors for a visual approach and landed without further incident.Having time to analyze the situation; and noting after landing/parking that the Avionics 1 & 2 were able to be switch back on; I conclude that the root cause of the systems associated with Avionics Bus 1 failing was from the iPad mount falling off the windscreen and hitting the switch on the way down. In personal reflection; I can recognize the irony that simply reaching over to check the avionics switches would have likely resolved the issue. But; the totality of the circumstances I had been suddenly faced with: 'an unexpected flight attitude deviation following an otherwise innocuous distraction; an initial observation of having a GPS signal failure'. Normally a failure of the GNS530/430; even if the failure was a complete loss of the entire unit; would not have resulted in the loss of the autopilot modes. Typically any normal failure of the autopilot is also accompanied by an audible alert. I had no immediate indication that the autopilot was off until observing the aircraft starting a descending turn. This precipitated the human factor contribution to the scenario of dealing with an otherwise unexplainable loss of avionics and uncommanded attitude deviation and no indication to which trained emergency checklist actions would be a prudent course of action. Overall troubleshooting based on system knowledge is a higher level brain function and at the time I did not have the luxury of 'stepping back' to think what might be going wrong. All that to say; there are no checklists specifically for an avionics failure (such as the switch some how getting turned off) or even what to do if the GPS fails. The assumed reactions remain in the realm of pilot knowledge and ability to troubleshoot the problem in lieu of following a checklist... in all likelihood with the assumption that the autopilot is still functional. This isn't a suggestion that we make a new checklist item; but rather the addition of random failure modes such as this during training to either establish situational memory or reinforce what to do if you don't know what to do. Finally; the root culprit of the situation... the iPad mount. This has been an ongoing 'issue' that has been simply tolerated by Company pilots. It hasn't been reported likely because we didn't think it was a big problem; would have never imagined it would lead to any problem; or have not been explicitly told that it is a problem if it occurs. There is also the ongoing back and forth with pilots who do not like having the mount and will remove it from the windscreen. The result is the mount ends up on the floor; getting dirty and damaged to the point that many of the suction cups do not effectively stay on the windscreen. In fact; in talking with another co-worker I discovered that this exact scenario happened to him during an AM departure a few weeks earlier and had hit both Avionics 1 & 2 switches. Since he saw it (and had the benefit of being VFR during the day) he just turned the switches back on and remounted the iPad. It has been my observation the suction cups seem to most frequently fail when climbing into colder temperatures; but this is not always the case. At this point; I believe it is safe to say that the current mounting system does not work... either by nature of system or as a result of the poor care and handling it as received over the past year or so. I will have to admit; the iPad mount coming off is something that I have observed and didn't report... and frankly should have reported and made a big stink over sooner. But I am now: at this point I do not believe the current iPad mounting system to be either effective nor safe.
Pilot reported iPAD falling out of it's mount; striking the Avionics Bus 1 and 2 switches; causing failures of most avionics and communication systems.