IFR panel with single GPS/nav radio

[dominikos]

looking at the pictures of Garmin G3X and Dynon HDX panels, I noticed that many of them don't have redundant GPS navigator and NAV radios while being IFR certfied panels. Is the thinking that 

1. both glass displays already have non-ifr GPS built-in, so that's a backup GPS?
2. NAV radios backup is no longer needed as people rarely fly ILS/VOR based navigation?

is the 2nd radio the only redundancy required?

Thanks, Dominik

[Ragsf15e]

No need for a backup gps.  
 

it is nice to have a backup approach capability though, so a #2 nav/com fulfills that (ils/vor).

[Ragsf15e]

Just now, Ragsf15e said:

No need for a backup gps.  
 

it is nice to have a backup approach capability though, so a #2 nav/com fulfills that (ils/vor).

Also, I doubt anyone considers the vfr backup gps as an ifr backup.  At least they shouldn’t.  If you lose your gps on an ifr flight it’s not a big deal.  Tell atc, navigate via vectors or vors.  Land via ils or visual approach, get gps fixed.  They just don’t break that much and it’s not catastrophic when they do.  Convenience is the real benefit to gps nav and approaches.  They get you anywhere and easier, but it shouldn’t cause significant issues if it were to break.

[kortopates]

My IFR flying would be severely limited to climbing through or descending through an occasional thin marine layer if I had only one nav/com radio. I don’t care how legal it is. Lost comm IMC isn’t my idea of fun.

I fly with dual IFR GTN’s - and a portable battery powered backup GPS. But the only loss of GPS I’ve experienced has been from jamming and it doesn’t matter how many GPS’s you have then! You always need to be prepared to fall back to terrestrial based nav. And when you don’t also have DME that’s not as easy as you might think.

what you need in your IFR panel is function of your risk tolerance and your wallet- but it takes a lot of IMC experience to really understand the risks and your ability to cope with failures.


Sent from my iPhone using Tapatalk

[PT20J]

1 hour ago, kortopates said:

And when you don’t also have DME that’s not as easy as you might think.

Did you keep your DME?

[Ragsf15e]

1 hour ago, kortopates said:

My IFR flying would be severely limited to climbing through or descending through an occasional thin marine layer if I had only one nav/com radio. I don’t care how legal it is. Lost comm IMC isn’t my idea of fun.

I fly with dual IFR GTN’s - and a portable battery powered backup GPS. But the only loss of GPS I’ve experienced has been from jamming and it doesn’t matter how many GPS’s you have then! You always need to be prepared to fall back to terrestrial based nav. And when you don’t also have DME that’s not as easy as you might think.

what you need in your IFR panel is function of your risk tolerance and your wallet- but it takes a lot of IMC experience to really understand the risks and your ability to cope with failures.


Sent from my iPhone using Tapatalk

I fully agree about wanting a backup radio.  Even just for the convenience of getting atis without leaving atc.  That 2nd radio might as well be a nav/comm so it can provide backup approach capability.  It’s having a backup gps that I think is overkill.  There’s nothing wrong with it, but losing gps shouldn’t be a catastrophe not if you’re still in good communication with atc.  

[dominikos]

I currently have GNS 430W + KX170B. I also have GNS 430 with brand new screen that was replaced by WAAS version. Worth somewhere around 3 AMUs. My dillemma is:

1. keep it as is, but KX170B won’t connect to G3X or Dynon HDX as NAV source - cost: 0 AMUs - 1 GPS/NAV/COM, 1 COM
2. replace KX170B with GNS 430 and have dual NAV/COM/GPS - cost: perhaps 1 AMU to install GNS and offset with 0.5 AMU value of KX170B - 2 GPS/NAV/COM
3. sell GNS 430, KX170B - around 3 AMUs, install remote radio (but no NAV) that works with G3X or Dynon. - 1 GPS/NAV/COM, 1 COM. Cost actually 1 AMU saving

I understand the value of VOR based navigation. But are we getting too paranoid? Or am I too optimistic? This is how I see it:

1. built-in capability (part of the panel)
   1. primary GPS/NAV/COM - IFR certified
   2. COM
   3. non-IFR GPS with battery backup
2. non-panel systems
   1. Sentry + FF
   2. hand held radio with NAV capability
   3. if needed, FF on iphone with built-in GPS

Is there a need for another NAV/COM in this configuration? Or even better, another GPS/NAV/COM?

If GPS/NAV/COM unit fails, there are two COM backups, non IFR GPS and handheld NAV.

If GPS signal is being scrambled, there is primary GPS/NAV/COM.

[kortopates]

1 hour ago, PT20J said:

Did you keep your DME?

No, my DME was in the form of the KNS80 which I couldn't wait to give to the Smithsonian when I put in GNS430's that later became GNS430W's. (I did briefly try out the CNX-480 first). But my rational is I didn't need to bring back an external DME with a dual IFR GPS for domestic flying because GPS loss is mostly pretty localized and here in the US airports aren't far apart with lots of options. Its really international flying I feel more vulnerable where airports are far apart and navaids are far less dense and you're much more on your own (a lot more time out of radar coverage). 

[carusoam]

Strive for two of everything in one form or another…. In case one breaks, or goes off line…

The important part of flying in IMC is to be able to get down through the clouds… (precision approach)

A WAAS gps and an ILS receiver are great for this as well…

Two glide slope  displays to go with them…

This logic will keep you from getting stuck on top of a low cloud layer… trying to find a hole, watching your Ceis levels…

Short of your own method of reaching the ground while in control… be familiar with the radar approach… ATC can supply this service at about 50 different airports around the country…

PP thoughts regarding selecting back up devices…

Best regards,

-a-

[Ragsf15e]

1 hour ago, dominikos said:

I currently have GNS 430W + KX170B. I also have GNS 430 with brand new screen that was replaced by WAAS version. Worth somewhere around 3 AMUs. My dillemma is:

1. keep it as is, but KX170B won’t connect to G3X or Dynon HDX as NAV source - cost: 0 AMUs - 1 GPS/NAV/COM, 1 COM
2. replace KX170B with GNS 430 and have dual NAV/COM/GPS - cost: perhaps 1 AMU to install GNS and offset with 0.5 AMU value of KX170B - 2 GPS/NAV/COM
3. sell GNS 430, KX170B - around 3 AMUs, install remote radio (but no NAV) that works with G3X or Dynon. - 1 GPS/NAV/COM, 1 COM. Cost actually 1 AMU saving

I understand the value of VOR based navigation. But are we getting too paranoid? Or am I too optimistic? This is how I see it:

1. built-in capability (part of the panel)
   1. primary GPS/NAV/COM - IFR certified
   2. COM
   3. non-IFR GPS with battery backup
2. non-panel systems
   1. Sentry + FF
   2. hand held radio with NAV capability
   3. if needed, FF on iphone with built-in GPS

Is there a need for another NAV/COM in this configuration? Or even better, another GPS/NAV/COM?

If GPS/NAV/COM unit fails, there are two COM backups, non IFR GPS and handheld NAV.

If GPS signal is being scrambled, there is primary GPS/NAV/COM.

Personally I’d want a second nav/com if you fly in actual imc.  If your gps dies, you’ll need a way down.  A comm radio is great but no help.  Non ifr gps are great but not good for an approach.  I’d want the nav2 connected to the g5 or it’s own obs/gs indicator.

If your least expensive option for that is dual 430w, nothing wrong with that.

Edited July 28, 2021 by Ragsf15e

[PT20J]

56 minutes ago, kortopates said:

No, my DME was in the form of the KNS80 which I couldn't wait to give to the Smithsonian when I put in GNS430's that later became GNS430W's. (I did briefly try out the CNX-480 first). But my rational is I didn't need to bring back an external DME with a dual IFR GPS for domestic flying because GPS loss is mostly pretty localized and here in the US airports aren't far apart with lots of options. Its really international flying I feel more vulnerable where airports are far apart and navaids are far less dense and you're much more on your own (a lot more time out of radar coverage). 

I remember the KNS80. Designed by Dave Wishard back when Ed King was building silver and gold avionics before he discovered making wine was more fun. Ah, the good old days -- may they never return (as Dick Collins used to say).

I asked because next month I'm tearing out all the old 1994 stuff (plus some 2010 additions by the previous owner) and I have an operable KN64 in the panel. It's tempting to keep it. But, I know as soon as I do it will crap out. Fortunately I still remember pilotage and dead reckoning. 

Skip

 

[PT20J]

13 minutes ago, Ragsf15e said:

Personally I’d want a second nav/com if you fly in actual imc.  If your gps dies, you’ll need a way down.  A comm radio is great but no help.  Non ifr gps are great but not good for an approach.  I’d want the nav2 connected to the g5 or it’s own obs/gs indicator.

If your least expensive option for that is dual 430w, nothing wrong with that.

Do the military bases still do GCAs? When I was in Anchorage, we used to do them into Elmendorf just for fun and the controllers liked it because they had to keep current, too. There was one female final controller that had a voice that just made you want to land and taxi up to the radar shack. Used to do that at Fritzsche Field near Monterey CA and Travis AFB. Nothing beats a soothing voice talking you down to earth.

Skip

[Jerry 5TJ]

5 hours ago, PT20J said:

Do the military bases still do GCAs?

Some civil as well as military airports offer radar approaches, yes.  PAR and ASR approaches are listed as “Radar Mins” in the approach plates index.  

Here is the list from Atlantic City International:

[Ragsf15e]

7 hours ago, PT20J said:

Do the military bases still do GCAs? When I was in Anchorage, we used to do them into Elmendorf just for fun and the controllers liked it because they had to keep current, too. There was one female final controller that had a voice that just made you want to land and taxi up to the radar shack. Used to do that at Fritzsche Field near Monterey CA and Travis AFB. Nothing beats a soothing voice talking you down to earth.

Skip

Yes, there are a few, but they are generally being abandoned in the US.  In Europe it’s a little different.  Navy bases have more typically.

They have currency requirements for the controllers that are difficult to keep up.  PARs require special radar equipment on the ground that’s expensive to maintain.

When I was instructing in the USAF (2011-2015), we had a requiment for students to do at least one and it was difficult to find one operating on our weekend cross country flights.

There doesn’t seem to be one within range of me here in Spokane, so although it’s a good idea, I wouldn’t count on it.

Edited July 28, 2021 by Ragsf15e

[kortopates]

Only the Army offers practice PAR/ASR approaches for us with a few exceptions. Of course, if you declare anything is possible! But the Air Force has largely abandoned them leaving the Navy and Army.


Sent from my iPhone using Tapatalk

[Ragsf15e]

32 minutes ago, kortopates said:

Only the Army offers practice PAR/ASR approaches for us with a few exceptions. Of course, if you declare anything is possible! But the Air Force has largely abandoned them leaving the Navy and Army.


Sent from my iPhone using Tapatalk

Couple of random civilian ones like KSJT too (ASR, no PAR), but I wouldn’t count on them having a current controller available when you need it.

[Jerry 5TJ]

6 hours ago, Ragsf15e said:

Couple of random civilian ones like KSJT too (ASR, no PAR), but I wouldn’t count on them having a current controller available when you need it.

True — I’ve taken students to Atlantic City and to NAS Patuxent but I call ahead to see if a controller is there.   

[Mooney Dog]

These days, you can have a single WAAS GPS for IFR, no NAV system at all. Now I think thats kind of silly, but its doable. Having a VOR as a backup is really nice. Having 2 GPS units is just failsafe is one fails or the military wants to do jam testing again. My dream setup used to be dual 430w, but now ive changed my mind to a 375 with 255a set up.

 

Your second point should be reworked. In the GA realm, people just fly RNAV/GPS 99% of the time. In the airline world, its a mix with 90% of it being GPS and landing almost always being some ils/ground based if the weather requires it. Not that you couldnt go out and jam an ILS, but i still trust the ILS to get me down to the runway a little more than an LPV.

 

Midwest panel builders also has a video that explains some about picking a navigator for IFR. 

 

[Yetti]

Well the Dynon Skyview Com Radio remote mounts.  So still two com radios.  You can bring the nav radio from the GPS into the screen.