Backups for navigation

Backup requirements depends a lot on mission. The main difference being VFR vs IFR. VFR is mostly about knowing where you are related to control zones, terminal airspace (so you don’t enter without clearance ) and visual reporting points. All this is given in a basic moving map GPS. In my RV8 (VFR only) I have a KMD150, it’s old but it does all you ever need VFR really. An iPad with a good app can do the same even better, although I would consider it more unreliable. Consumer tablets works poor in direct sunlight and they shut down in high temps. I use both for redundancy. Cloud base and visibility info for the route is critical VFR but that’s mostly a preflight thing.

IFR however is a different and much more critical game should something fail and one is unable to stick to procedures, control or situational awareness is lost, therefor redundancy is also more critical. While not knowing the correct approach procedure might get one in trouble VFR, it can turn fatal IFR in IMC.
In todays world backup has never been easier. Without it even a vacuum pump failure can be deadly.

When I started flying in very flat central Texas in the 70s, the backup was to get low enough to read water towers. The only real risk those days was radio towers – there were a lot and they were tall, hard to see, and had guy-wires that were impossible to see.

Today, I’ve got Skydemon on the ipad and iphone, along with FF and Air Nav Pro. Also, google maps works pretty well in the air too. And a compass. And an EFIS with Jeppesen nav data. Not sure which is primary, and which is backup, but flying around Switzerland, you only need your eyes to navigate – it’s impossible to get lost here!

Interesting thread!
As far as I am concerned, my backup is paper charts and printed out approach charts of the destination.
I usually navigate as much as I can using paper charts, navigation logs, etc. As a matter of fact, I like that old school method. However I have to admit that, when on shorter trips (30 mins or so), laziness gets the upper hand and I just follow the GPS (skydemon on ipad)…

The biggest issue I see is this sort of thing i.e. consumer portable gear failing; in the case of tablets, especially Apple ones, shutting down in sunshine. But you can’t have a backup for that, because that will shut down also.

I have a yoke-mounted Aera 660 as the nav backup. It also backs up airport diagrams (Garmin safetaxi) when the Ipad has shut down

Then I have a Yaesu 750 in a bag on the back seat, but this would have only a short range.

The approach plates for a planned trip are printed out, so no battery to go flat. Then I have a backup via Foreflight and AIP plates but that assumes the Ipad has not failed.

There is now a backup alternator too which does 15A – enough to run more or less the whole plane.

One can easily get overly religious with backups The only backup you need is a phone. Worst case scenario is Russian jamming of GPS (which is a real thing here, mostly problematic for airliners). Android devices (I have no clue about iPhone), still work without GPS. Not pinpoint, but more like thumb point, more than good enough to navigate after (I don’t think Skydemon will work with no GPS). You need a connection though, but can’t imagine that being a problem in densely populated Europe. It’s not a problem here in Norway with huge deserted areas. Even without no connection of any kind, there is still a map or two in there that can be used.

A good magnetic compass is a good thing though. I’m just sick and tired of non TSO’d compasses that swirl around and do no good. It seems like everyone can make a compass, and everyone does. 90% of those really shouldn’t A TSO’d compass is the next thing that get installed in the Savannah.

Another thing is that dead reckoning in unknown terrain requires practice. I learned that this summer with the competitions we had. You need a map of some kind, and you need a way to figure out your heading. With those two, the precision you can achieve is staggering. No need for rulers or watches when the exact arrival time is not of the essence. Even if your phone has lots of maps, do you remember where they are? are they downloaded? will they work with no GPS signal, will they show your position with no GPS signal and so on.

I also learned to fly before GPS. A simple VOR will solve most problems in theory at least. But when you haven’t used it for more than 20 years… I’m not sure how much it would help today Today these surveillance radars are a thing also. You know exactly where you are, if you only ask.

I always carry my iPad with ForeFlight which, depending on the airplane I fly that day, gets its data either from the panel via Garmin Flightstream or from a Stratus 3 external GPS/ADS-B receiver. On longer x-country trips I carry a second iPad in case the main one runs out of juice and also a second external GPS unit, a DUAL 160. As I always have my phone on me, that’s the last line of defense, iPhone also running ForeFlight. I normally don’t carry paper charts, but for longer trips throw some old ones in the bag just in case.

I feel I am fairly well backed up in my Bonanza. My primary navigation is via the GTN 750Xi. My primary instruments are by the G500TXi. I have a standby alternator that will power 20 amps of systems. The ships battery will power about 20 to 30 minutes of avionics usage. I have a G5 with an independent battery backup power source to backup the G500TXi. I have a GDL 88 ADS-B system that backs up my primary weather receiver a GDL 69A. Also have a WX500 Stormscope. I also have several portable battery powered ADS-B receivers in my pack that can provide backup AHRS, GPS, ADS-B weather and Traffic (a Stratus 2, a GDL39D, and a Sentry). I also have a Garmin Aera 796. I use an iPad Mini 5 with both ForeFlight and GP on it. It is backed up with a iPhone 13 Max Pro with the same software options. I have US charts and world wide Jeppesen Charts. I don’t use the GPSS function provided by the G500TXi, but kept my Stec ST901 GPSS which allows me to turn off the G500TXi and still provide GPS course guidance including lateral guidance for approaches from the GTN 750Xi. If GPS fails or their is a system wide GPS jamming event, my number 2 Nav system is a KNS80 that provides DME, VOR, RNAV (Rho Theta), and ILS. If the G500TXi is working, it can provide guidance for VOR courses and ILS to the autopilot. If not, then it has its own dedicated GI-106A CDI that can provide VOR, RNAV (Rho Theta) and ILS indications. I only have one transponder, but the GDL 88 would provide ATC with surveillance information if the transponder failed. I have two Com units and a portable iCom VHF radio with a headset adapter. I also have my vertical magnetic compass. I have two spare noise cancelling headsets on board.

One could use different software on the primary and backup devices, for example, SkyDemon on iPad and ForeFlight on the phone. If there’s a condition that crashes your software, it may also be met on the other device. This rule isn’t followed in commercial environments, where it is enough that both pilots use iPads with the same software. Another backup would be charts in your avionics and most of the time you can simply ask for vectors.

Seba wrote:

Yes, essentially this. Anyone nowadays has a couple of electronic devices on board, without even thinking about it. You just need to make sure that some EFB is installed in more than one of them, and you already have enough redundancy to at least bring you safely to the ground in case of issues.

I always have Skydemon with up-to-date charts and plates on my phone…