N546RV
Well Known Member
I'm getting hip-deep into electrical planning, which in turn has me thinking through various failure states and what equipment does and does not need to survive said failures. This of course gets fun quickly because it's easy to go way down the rabbit hole of uber-redundancy (a topic already being discussed in other threads here).
So that leads to the core question I'm having, which is deciding that "stuff" I really need. I plan on equipping the aircraft for IFR flight but not flying in actual IMC on any kind of regular basis. Avionics will be Dynon (likely two displays, plus Skyview radio/intercom/transponder) and probably a GPS-175 for the TSO GPS role. I don't plan on installing a second com radio, and instead keeping a handheld on board for backup purposes.
The first and most obvious thing to me is maintaining an attitude reference. I'll be equipping one or both displays with backup batteries, so even in case of a total electrical failure I'll retain the attitude reference.
After that, though, honestly I'm starting to feel like everything else is OK to do without. Primary com fails? I've go the handheld. Transponder is dead? I don't really care. ADS-B receiver? Totally nonessential. The GPS-175, at least, is debatable - I'll still be able to navigate via Skyview but have no capability to shoot an approach. The only other things I can think of are the boost pump and pitot heat, which both seem nice-to-have-but-not-essential to me.
Basically, this all boils down to whether it's worth it to have any sort of e-bus (pick your preferred "e" word here) at all. I plan on using a VP-X for circuit protection, and wiring up backup paths for these devices, while not horrible, does pretty quickly add some complexity inflation to the system. And I'm honestly not convinced that it's worth it, but I'm here to allow people to change my mind if necessary.
So with that in mind, what's "essential" in your plane? What's faulty in my reasoning above? Tear my rationales apart, that's what I'm here for.
So that leads to the core question I'm having, which is deciding that "stuff" I really need. I plan on equipping the aircraft for IFR flight but not flying in actual IMC on any kind of regular basis. Avionics will be Dynon (likely two displays, plus Skyview radio/intercom/transponder) and probably a GPS-175 for the TSO GPS role. I don't plan on installing a second com radio, and instead keeping a handheld on board for backup purposes.
The first and most obvious thing to me is maintaining an attitude reference. I'll be equipping one or both displays with backup batteries, so even in case of a total electrical failure I'll retain the attitude reference.
After that, though, honestly I'm starting to feel like everything else is OK to do without. Primary com fails? I've go the handheld. Transponder is dead? I don't really care. ADS-B receiver? Totally nonessential. The GPS-175, at least, is debatable - I'll still be able to navigate via Skyview but have no capability to shoot an approach. The only other things I can think of are the boost pump and pitot heat, which both seem nice-to-have-but-not-essential to me.
Basically, this all boils down to whether it's worth it to have any sort of e-bus (pick your preferred "e" word here) at all. I plan on using a VP-X for circuit protection, and wiring up backup paths for these devices, while not horrible, does pretty quickly add some complexity inflation to the system. And I'm honestly not convinced that it's worth it, but I'm here to allow people to change my mind if necessary.
So with that in mind, what's "essential" in your plane? What's faulty in my reasoning above? Tear my rationales apart, that's what I'm here for.