Good backups in all-electric and vacuum a/c

As another person noted, the turn coordinator in the SR20 and SR22 has a pair of 9V batteries to back them up just in case everything else goes dead.

And another person said, have a hand-held to back up your communications radios. I do this and once used my hand-held when the a/c’s radios jammed up. So I think this is a great idea.

Something that I haven’t seen posted yet is that one can use the HSI page on your GPS, which can be a battery-powered GPS, as backup for the heading indicator. I never fly IFR w/o my Garmin GPS (was a 195, now a 295). I fly club planes that don’t have any other GPS, or at most have an ancient non-map difficult-to-use, VFR, GPS. I have long thought that if I had a question about my heading indicator’s health, I’d look at the simulated HSI on the Garmin and compare, or just use the simulated HSI. They don’t show quite the same thing, one shows which way the A/C is pointed and the other shows which way it is going. The difference is wind and slip. Given that you’re not slipping in IMC, the difference is wind. And though this can be a significant difference, I don’t think that it would have a practical effect because you chose headings based on vectors, which controllers adjust based on observed course, or on what works to get to a fix, which the pilot adjusts as well.

Does this make sense, or am I all wet?

I am thrilled to be done with vacuum systems.

I totally agree with the comparison with ADF/NDB’s. I am curious to see the wiring diagram for the SR22 to see where the common points of failure are and how those are handled.

In the Duchess I fly, there are two busses, and each has about half the nav and have the comm’s. I’d guess that one of the '430’s in the SR22 is connected to one bus and the other '430 to the other bus. I’d further guess that there is a switch to connect or split the two busses, to allow for powering the whole a/c from one power source (switch on) or for isolating failures (switch off). But this is pure speculation. I wish Cirrus would put more information on their web site.

Makes sense to me! I also have a GPSMAP 295, as a backup to my panel mounted GX55. I use the 295’s HSI a LOT since my TB20 doesn’t have one. For most other purposes I prefer the GX55, but the 295’s HSI is worth the price all by itself.

Joe Mazza

Former Position Holder

As another person noted, the turn coordinator in the SR20 and SR22 has a pair of 9V batteries to back them up just in case everything else goes dead.

And another person said, have a hand-held to back up your communications radios. I do this and once used my hand-held when the a/c’s radios jammed up. So I think this is a great idea.

Something that I haven’t seen posted yet is that one can use the HSI page on your GPS, which can be a battery-powered GPS, as backup for the heading indicator. I never fly IFR w/o my Garmin GPS (was a 195, now a 295). I fly club planes that don’t have any other GPS, or at most have an ancient non-map difficult-to-use, VFR, GPS. I have long thought that if I had a question about my heading indicator’s health, I’d look at the simulated HSI on the Garmin and compare, or just use the simulated HSI. They don’t show quite the same thing, one shows which way the A/C is pointed and the other shows which way it is going. The difference is wind and slip. Given that you’re not slipping in IMC, the difference is wind. And though this can be a significant difference, I don’t think that it would have a practical effect because you chose headings based on vectors, which controllers adjust based on observed course, or on what works to get to a fix, which the pilot adjusts as well.

Does this make sense, or am I all wet?

I am thrilled to be done with vacuum systems.

I totally agree with the comparison with ADF/NDB’s. I am curious to see the wiring diagram for the SR22 to see where the common points of failure are and how those are handled.

In the Duchess I fly, there are two busses, and each has about half the nav and have the comm’s. I’d guess that one of the '430’s in the SR22 is connected to one bus and the other '430 to the other bus. I’d further guess that there is a switch to connect or split the two busses, to allow for powering the whole a/c from one power source (switch on) or for isolating failures (switch off). But this is pure speculation. I wish Cirrus would put more information on their web site.

Something that I haven’t seen posted yet is that one can use the HSI page on your GPS, which can be a battery-powered GPS, as backup for the heading indicator. I never fly IFR w/o my Garmin GPS (was a 195, now a 295). I fly club planes that don’t have any other GPS, or at most have an ancient non-map difficult-to-use, VFR, GPS. I have long thought that if I had a question about my heading indicator’s health, I’d look at the simulated HSI on the Garmin and compare, or just use the simulated HSI. They don’t show quite the same thing, one shows which way the A/C is pointed and the other shows which way it is going. The difference is wind and slip. Given that you’re not slipping in IMC, the difference is wind. And though this can be a significant difference, I don’t think that it would have a practical effect because you chose headings based on vectors, which controllers adjust based on observed course, or on what works to get to a fix, which the pilot adjusts as well.

Does this make sense, or am I all wet?

It makes perfect sense! Curmudgeon I may be, but I have consistently doubted the value of an expensive to buy and expensive to fix panel-mount HSI. Handheld GPS all the way down to the GPS Pilot III at ~$550 provide an HSI page at a tiny fraction of the cost of a Century or Sandel. In my 260se I have a Garmin 195–maybe soon a 295–on the yoke interfaced to the GNS430. The 430 provides all flightplan and approach info to the 195 automatically. If I want to look at an HSI I can just press “page” once or twice and there it is, along with a CDI if I want it. Besides, with the 430’s map and little pink course line you would have to be snorting a controlled substance to lose situational awareness. :slight_smile:

Why do you have the 430 drive the 195/295? My 295 does just fine on its own.

Perhaps it’s to “stay legal” since the 430 is IFR certified and the 195/295 are not? If so, is it actually legal to do this, since I presume some of the certification has to do with interfaces, displays, etc.?

A small point, I admit. Just curious.

Joe

Former Position Holder

Something that I haven’t seen posted yet is that one can use the HSI page on your GPS, which can be a battery-powered GPS, as backup for the heading indicator. I never fly IFR w/o my Garmin GPS (was a 195, now a 295). I fly club planes that don’t have any other GPS, or at most have an ancient non-map difficult-to-use, VFR, GPS. I have long thought that if I had a question about my heading indicator’s health, I’d look at the simulated HSI on the Garmin and compare, or just use the simulated HSI. They don’t show quite the same thing, one shows which way the A/C is pointed and the other shows which way it is going. The difference is wind and slip. Given that you’re not slipping in IMC, the difference is wind. And though this can be a significant difference, I don’t think that it would have a practical effect because you chose headings based on vectors, which controllers adjust based on observed course, or on what works to get to a fix, which the pilot adjusts as well.

Does this make sense, or am I all wet?

It makes perfect sense! Curmudgeon I may be, but I have consistently doubted the value of an expensive to buy and expensive to fix panel-mount HSI. Handheld GPS all the way down to the GPS Pilot III at ~$550 provide an HSI page at a tiny fraction of the cost of a Century or Sandel. In my 260se I have a Garmin 195–maybe soon a 295–on the yoke interfaced to the GNS430. The 430 provides all flightplan and approach info to the 195 automatically. If I want to look at an HSI I can just press “page” once or twice and there it is, along with a CDI if I want it. Besides, with the 430’s map and little pink course line you would have to be snorting a controlled substance to lose situational awareness. :slight_smile:

In my 260se I have a Garmin 195–maybe soon a 295–on the yoke interfaced to the GNS430. The 430 provides all flightplan and approach info to the 195 automatically. If I want to look at an HSI I can just press “page” once or twice and there it is, along with a CDI if I want it. Besides, with the 430’s map and little pink course line you would have to be snorting a controlled substance to lose situational awareness. :slight_smile:

Kevin, can you describe in more detail how you have interfaced the 295 to the 430? How does the wiring, software interface, etc. work? Thanks!

Having re-read your post I now see the advantage of interfacing with the 430: Only having to enter flight plan info once, and with the better 430 interface.

I wonder if the 295 will accept similar input from my GX55? I’ll have to check that out.

Joe

Why do you have the 430 drive the 195/295? My 295 does just fine on its own.

Perhaps it’s to “stay legal” since the 430 is IFR certified and the 195/295 are not? If so, is it actually legal to do this, since I presume some of the certification has to do with interfaces, displays, etc.?

A small point, I admit. Just curious.

Joe

Former Position Holder

Something that I haven’t seen posted yet is that one can use the HSI page on your GPS, which can be a battery-powered GPS, as backup for the heading indicator. I never fly IFR w/o my Garmin GPS (was a 195, now a 295). I fly club planes that don’t have any other GPS, or at most have an ancient non-map difficult-to-use, VFR, GPS. I have long thought that if I had a question about my heading indicator’s health, I’d look at the simulated HSI on the Garmin and compare, or just use the simulated HSI. They don’t show quite the same thing, one shows which way the A/C is pointed and the other shows which way it is going. The difference is wind and slip. Given that you’re not slipping in IMC, the difference is wind. And though this can be a significant difference, I don’t think that it would have a practical effect because you chose headings based on vectors, which controllers adjust based on observed course, or on what works to get to a fix, which the pilot adjusts as well.

Does this make sense, or am I all wet?

It makes perfect sense! Curmudgeon I may be, but I have consistently doubted the value of an expensive to buy and expensive to fix panel-mount HSI. Handheld GPS all the way down to the GPS Pilot III at ~$550 provide an HSI page at a tiny fraction of the cost of a Century or Sandel. In my 260se I have a Garmin 195–maybe soon a 295–on the yoke interfaced to the GNS430. The 430 provides all flightplan and approach info to the 195 automatically. If I want to look at an HSI I can just press “page” once or twice and there it is, along with a CDI if I want it. Besides, with the 430’s map and little pink course line you would have to be snorting a controlled substance to lose situational awareness. :slight_smile:

Kevin, can you describe in more detail how you have interfaced the 295 to the 430? How does the wiring, software interface, etc. work? Thanks!

This was done by the avionics shop that installed the rest of the stuff in the panel, including the 430. I’m sort of an ignoramus about such things, but my understanding is that it’s a straightforward RS232 connection and the 430 can talk to the 195 with no difficulty. The cable that makes the link also provides a “ship’s power” connection so the 195 doesn’t eat batteries (the 295 would be much worse in this regard!).