49clipper
 

Yes, have a compass, and in my 41+ years of flying, I have never had an electrical device (over time) that did not fail at some point, normally when I needed it the most, Except for possibly a turn coordinator. I am looking for an EFIS (primarily because i need some attitude awareness and they are cool), but 'I will not' give up my steam gauge AS, alt, and compass on the install.
Jim AP/IA/CFI/RV-6
JMHO

A properly designed glass-panel system should be single-fault tolerant within the designed operating environment. Redundant components (such as EFISes, comm radios, busses, etc.), backup batteries (either on a buss or component level, depending on design), etc.

It's probably not feasible in a light aircraft to go all the way to full cross-strapping components, but there's no reason it can't be (with perhaps carefully chosen exceptions like the pitot/static system) as reliable or more so than vacuum gauges and mechanical devices.

Look down. From Maine to the Rockies, the roads run N-S-E-W. Built in compass. I haven't flown with a compass for almost 17 years now.

ATC still cares quite a bit.

Actually I've found that not to be true. When you get a heading (except for a charted departure or arrival) they are guessing at what heading they really want you to fly. They will then make corrections as needed for you to fly the ground track they want.

Yes ATC does care
 

At least for me one occasion. I was being vectored in class C airspace on a very windy day at 3,000 ft. I had been messing with my GRT EFIS settings(before the flight) and forgot to switch it back to HDG. I was given a heading to follow, needles to say the controller called me to be sure I was on assigned heading since I was off 20 degrees from everyone else. Didn't take me long to figure out the EFIS was in TRK mode.

Gary

Yeah, you're right flyinga, I did a crappy job of writing what I meant. They could care less about the literal heading of your airplane - the track is what matters for convergence. They do care that you fly an assigned heading is what I should have said. I agree, if everyone had the means of precisely flying track, it would be the way to go.

I was told by the MDRA (outfit that inspects homebuilts in
Canada) that there are changes to the canadian regs coming whereby you can skip having a compass provided you can show that you have 30 min of operation of your compass equivalent in the event of a failure of the primary electrical system. He said they would be in place by the time I was finished. Perhaps he was just trying to say that I didn't have a hope of being finished in the next ten yrs?:p

I might add that I do lots of xcountry flying and I use the ipad, but before that I used a map and still didn't really use the compass much. Losing heading info is not exactly a dire emergency. That DAR mentioned earlier is basically demanding a higher level of reliability for heading information (2 efis and a whisky compass) than he is for the engine which makes no sense at all. Failure analysis drives reliabilty requirements based on the probability of the failure AND the failure's consequences. Losing a compass is not terribly serious, unless you were already lost!

Only once in my entire flying "career" have I ever used a whisky compass to help me get home was very early after I'd got my PPASEL, I was flying a rented C172 with no nav gear (vor, loran or gps) onboard... I'd flown down to near the DFW metromess and was on my way home when I looked down and noticed the roads didn't look right and suddenly I felt disoriented to direction. The vacuum driven DG had drifted a lot so I just used the whisky compass to reset the DG and fly north until I could see the Red River then I knew all I had to do was look to the west along the river and there was home... so yes, a whisky compass still can have value in navigation. Now I practically have the entire N Texas landscape memorized so it doesn't matter but to a green newbie it can be a good, practical instrument to have at you disposal.

CAR 605.14:
Note that by the wording of the regulations, a Dynon D10A would meet this requirement, as it has an internal backup battery and does operate independent of the electrical generating system.

That being said, MD-RA will not allow an Amateur-Built Aircraft to pass their final inspection unless it has a whiskey or card compass, as per an internal policy at the MD-RA... They require an independent *mechanical* compass, which is not what the regs state.