I had an *interesting* issue on my way home from 5A1 on Sunday. Just prior to entering the Appalachians, I got an "VPX Fault" Crew Alerting System indication, then the PFD went black, then thankfully recycled and stayed on (*OR* it could have been the PFD going black, recycling, then coming back with the "VPX Fault" CAS.) Once I settled down, I checked the VPX page on the MFD, and saw that the (ASA) cowl flap had short circuited, and would not reset. The rest of the flight was uneventful (except for the declining ceiling as I crossed the mountains.)
Yesterday, I removed the cowl flap and discovered that the bolt that connects the actuator to the flap crank / lever was missing. The actuator had fallen flush with the inside of the flap, then the piston had jammed itself into the bracket that connects the crank to the flap door. Luckily for me, the good people at Anti Splat Aero are sending me a new actuator free of charge. What probably happened is that when I replaced the actuator earlier this year (another story, and not the fault of ASA,) I either misapplied the Loctite on the nut, didn't use the correct formulation, or neglected to do it at all. The Loctite is ESSENTIAL, as I discovered.
What concerns me is the recycling of the PFD after the short circuit. I would have thought that the VP-X would have isolated the the cowl flap short from the G3X PFD, thus protecting it from a spike / recycle. In my system design, the MFD is the only display that is connected to the IBBS, and it remained on. I *think* it remained set up as the MFD while the PFD was recycling. The other devices connected to the IBBS are the GSU, the GEA, and the GTX, which is slightly different than the recommendation of both GDUs. I have the GTX on the IBBS because of the airspace I typically fly in, but I am reconsidering my design to switch the backup battery to the PFD from the GTX.
Anyway, comments are appreciated.
Yesterday, I removed the cowl flap and discovered that the bolt that connects the actuator to the flap crank / lever was missing. The actuator had fallen flush with the inside of the flap, then the piston had jammed itself into the bracket that connects the crank to the flap door. Luckily for me, the good people at Anti Splat Aero are sending me a new actuator free of charge. What probably happened is that when I replaced the actuator earlier this year (another story, and not the fault of ASA,) I either misapplied the Loctite on the nut, didn't use the correct formulation, or neglected to do it at all. The Loctite is ESSENTIAL, as I discovered.
What concerns me is the recycling of the PFD after the short circuit. I would have thought that the VP-X would have isolated the the cowl flap short from the G3X PFD, thus protecting it from a spike / recycle. In my system design, the MFD is the only display that is connected to the IBBS, and it remained on. I *think* it remained set up as the MFD while the PFD was recycling. The other devices connected to the IBBS are the GSU, the GEA, and the GTX, which is slightly different than the recommendation of both GDUs. I have the GTX on the IBBS because of the airspace I typically fly in, but I am reconsidering my design to switch the backup battery to the PFD from the GTX.
Anyway, comments are appreciated.
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