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Backup IFR Equipment Requirements

Steve Daudelin

I'm New Here
Finally starting to seriously consider what it would take to finally build an airplane and the RV-14 seems to fit my needs. As I go through the "what if" stages, I'm confused about meeting FAR requirements for backup instruments for IFR flight when using a glass cockpit. Can you more experienced homebuilders out there fill me in on what backup instruments (if any) are legally required for IFR ops with a glass cockpit?

Thanks in advance for your inputs.
 
There are no real "backup" instruments required for an experimental. The closest thing to backup would be a "gyroscopic rate of turn" and a "gyroscopic pitch and bank indicator."

I think most of us add backups to our own comfort level. Some confusion seems to arise since many retrofitted glass cockpits (in certified aircraft) require certain backups via the STC.
 
Not sure if it counts as backup but i do believe it's wise to include VOR capability in addition to GPS.

Without a WAAS GPS, an approach to an alternate airport must be something other than GPS. If you have a WAAS GPS installed, I don't believe that requirement exists. (Anyone correct me if I'm wrong about that!)

But, if it was me, I think I'd still like to have an alternative to the GPS approach.
 
Hi Steve,

As others have mentioned, there is no actual "legal" requirement for IFR in a part 91 airplane (there is in other aircraft like 121, etc..), but for our RV type planes in the US, nothing specifically required. That being said, in other countries there are very specific requirements that can vary depending on country.

Lastly, what is "required" verses what is a "good idea" are two different things. Given that you can purchase a 2nd ADAHRS for most EFIS systems in the high hundreds of dollars, or a completely stand alone backup EFIS for around $1K-$2K, it seems like a wise investment to me an I encourage that for IFR type installations.

Just my 2 cents as usual!

Cheers,
Stein
 
Not sure if it counts as backup but i do believe it's wise to include VOR capability in addition to GPS.

Without a WAAS GPS, an approach to an alternate airport must be something other than GPS. If you have a WAAS GPS installed, I don't believe that requirement exists. (Anyone correct me if I'm wrong about that!)

But, if it was me, I think I'd still like to have an alternative to the GPS approach.

Strictly speaking, it's the gps TSO that matters. TSO 145/146 (pretty much only WAAS boxes) is approved for stand alone operation. TSO 129 (pretty much non WAAS boxes) requires other (eg, vor) nav equipment be on board.

Your operating limitations most likely say you must follow FAR 91.205 for ifr. That's the minimum; backups are up to you. As others have said, I want an 'out' for most failure scenarios. For me that means a backup efis with its own battery, separate vor and gps receivers, battery powered vor and gps handhelds. ymmv.
 
Thanks for all the input. I've been flying IFR under Part 91 for some time and agree with all the comments on having adequate backup for real-world ops, including WAAS requirements. I'm a little new to the experimental world so your experienced inputs are very helpful. Thanks again!
 
E-AB equals Options

There are a lot of options when it comes to our E-AB (Experimental - Amateur Built) aircraft.

Stein builds custom panels for a living and probably has the best handle on what others have done to provide redundancy in their panels.

My personal favorite is the Dynon D1 and D2 Pocket Panels. The Pocket Panels have an internal battery and are not tied into your pitot static system, thus, if either become blocked, they will not impact them and in the event of an alternator failure, they will continue to run for a few hours.

For backup nav, get a WAAS enabled handheld and an AirGizmos Panel Dock to mount it.

The communicate part of the equation would be nice but as you know, there are procedures to handle radio failures. Still, you could mount one of Sporty's SP-400 Handheld NAV/COM's in your panel and wire it to a separate antenna and put a pair of headset plugs on the panel just for it.

With those three items installed, you can keep your plane upright, navigate, do an ILS, and communicate during a full electrical failure. At least, in theory. I've never flown with the SP-400, so I don't know how well it works and the handheld COM radios I have used in flight without an external antenna are about useless. A better radio than those I have tried might work better.
 
Options abound...

I gladly sold my little Dynons (6 and 10) to go with a GRT Mini. Very similar cost, but no comparison in functionality. A complete no-brainer for me, but I was putting in other GRT gear for which the Mini would serve as back up, so that helped clinch it.

Not only are my artificial horizon and air data instruments backed up by the Mini, but so are my moving map and synthetic vision :D No regrets.

-Stormy
 
Have had a few dramas in Australia when we went for IFR certification. The SAAA (EAA of Australia) stopped certifying IFR for quite some time and we were one of the first to get IFR when they reviewed all the requirements.

Essentially they mandated a standby TSO'd AH, ASI and Altimeter.. which is really a load of **** as our TSO'd altimeter and ASI is no where near as accurate as our Garmin G3X.

We will eventually replace the steam backup gauges with Glass but for now they work.
 
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