Backup Gauge Decision

[BobTurner]

Originally Posted by lr172

I am very concerned about failure of the EFIS during IFR flight and want to back it up the best that I can. Can I assume that attitude indication, beyond the TC, is a critical element to safe IFR and therefore requiring backup? My EFIS has a backup battery, as does my 396 GPS. My Trio AP will give me TC ability. I am thinking the VSI might also be a good backup to help as well. It won't be in my scan area, but at least it is there.

Thanks again for guiding a junior aviator here.

Larry

In my opinion, the answer to your question is 'yes'. I would strongly urge you to consider a stand alone, battery powered, attitude source. There are several available in the $1-$2K range. In my cfii experience, pilots do not practice partial panel enough, and their pp skills are weak. Worse, pilots who earn their instrument rating behind an EFIS have a very hard time going 'back' to steam gauges, and their pp skills tend to be very poor. In my opinion, in a real failure scenario, you will be so fixated on those turn coordinator bars on the Trio that having a VSI outside your scan range would be totally useless.

[Flyingdreamz]

Originally Posted by BobTurner

In my opinion, the answer to your question is 'yes'. I would strongly urge you to consider a stand alone, battery powered, attitude source. There are several available in the $1-$2K range. In my cfii experience, pilots do not practice partial panel enough, and their pp skills are weak. Worse, pilots who earn their instrument rating behind an EFIS have a very hard time going 'back' to steam gauges, and their pp skills tend to be very poor. In my opinion, in a real failure scenario, you will be so fixated on those turn coordinator bars on the Trio that having a VSI outside your scan range would be totally useless.

I totally second having a secondary attitude source. It still baffles me that Cessna and Beech dont do that with there G1000 setups (Piper, and the late Mooney did)

I hate to go slightly off topic but Bob, what would you say is good ratio of partial panel to no failures flight would you say is appropriate? I for example, did 35 hours for my IRA (part 141), I flew steam, and glass (G500, and Adivine ) with the split 45/55, I flew in a partial panel situation, maybe 28 of the 35 hours. (My cross countries where in actual, and the first 2 flights I had we did not do PP) I ask because I am working to come a CFI and II.

[BobTurner]

Originally Posted by Flyingdreamz

I hate to go slightly off topic but Bob, what would you say is good ratio of partial panel to no failures flight would you say is appropriate? I for example, did 35 hours for my IRA (part 141), I flew steam, and glass (G500, and Adivine ) with the split 45/55, I flew in a partial panel situation, maybe 28 of the 35 hours. (My cross countries where in actual, and the first 2 flights I had we did not do PP) I ask because I am working to come a CFI and II.

There is no single answer to this - people vary a lot. Just that myself and a couple of other cfii's had noticed - to generalize - that pilots who learn on steam transition to glass quicker than vice versa. And, pilots who learn on glass often don't even see anything that looks like a turn coordinator - just some marks where the standard rate turn is. Also, since p/p is nearly always just "practiced", don't discount the psychological factor. I was once doing an IPC with a pretty good pilot, doing the initial part of an ILS p/p (conventional panel in a 172). He was under the hood (night) doing pretty well. As we flew into a thin cloud layer, I said, "Well, we're in actual now, so don't sc*** up." His performance immediately went downhill; he started fixating on the TC and altimeter and forgot to track the localizer. When I pointed that out he was still reluctant to introduce any bank at all.
I might also add that pilots who learn with a gps never seem to have a good sense of position awareness if the gps goes away, compared to those who learned without one.

[AaronG]

I was also worried about a complete Efis failure during IFR, or a total failure of the electrical system for whatever reason.

My backup is a round altimeter and airspeed indicator (pitot static driven) with the trutrak adi in the middle. My GPS496 with its own battery powers the ground track on the adi (no wind correction required when flying the approach using the adi ground track), and the adi has its own backup battery.

Flying approaches is no harder than the efis, and the price was reasonable.

Aaron

[GalinHdz]

My 2 cents FWIW:

The probabilities of having a modern well designed and installed digital EFIS fail is much lower than having a steam gauge fail. It is more probable that the EFIS will display inaccurate data instead of just completely fail. Therefore, having a backup system (EFIS or steam) in real IMC does not address the more probable situation, which indication is correct and which one will kill you?

The only way to address this is to have a third independent system (triple redundancy) as a tie-breaker. You just need to get enough information so you can decide which of the other two to use and which to ignore. The third system doesn't have to be real fancy. It can be a portable GPS, an iPad or even a smartphone with some kind of position app. So for real IMC, no matter which you select as backup, have a method to figure out which one of your systems to ignore and which one is correct.

[flightlogic]

GRT mini B. battery power backup. You can continue until the gas is gone if you need to. It will get you to any waypoint via gps and keep you upright. Check it out.