GPS jamming and spoofing and relying on GPS, and GPS backup plan ?

I posted this several years ago:

FOG (fibre optic gyro) costs are slowly falling and if you are happy to have an uncertified (but rock solid, military spec) inertial backup, driving some kind of portable moving map device via NMEA, you can get it for about 20k. The name I was thinking of escapes me but this is the sort of stuff. These boxes have a GPS antenna socket at one end, and output RS232 NMEA at the other end! If/when GPS goes, the NMEA output just carries on….

Airliners already have exactly that, with DME/DME or (in modern ones) GPS corrections.

That’s the state of the art technological solution to the question posed by the OP…

Timothy – I was referring to the fake tutorial and the fake exam from a 1990s PPL QB, and a total stonewall from those responsible in the CAA. And I happen to know I am not the only one to gave got exactly the same. All designed to leave a very foul taste in the pilot’s mouth. So Aveling’s point (paraphrasing as “would you really call up ATC if unsure of position?”) is pretty valid. Not many pilots would do it while declaring their GPS stopped working, especially with the regulatory apparatus being staffed with ex RAF people (Mk1 eyeball, Mk 1 compass, Mk 1 stopwatch). I know things are changing but not at the persecution enforcement end.

Reading the report about GPS jamming in the US made me remember getting into a friend’s plane, starting her up and then taking off, intent on flying it for him to an avionics shop to have the GPS checked over – it wasn’t working for some reason or other. I had told myself – you’ll be ok, just use Sky Map. However I was so used to flying using my GNS430s, I had forgotten about this and left it in my pilot bag; my pilot bag was – you guessed it – placed in the baggage area of the plane, which, being alone in a plane with no autopilot, meant it was to all intents and purposes unavailable to me.

Once that dawned on me, that I was without any GPS at all, I was seriously considering turning around and landing in order to get the bag from the back to give me some sort of GPS – it was incredible how reliant I had become on it. Fortunately the distance wasn’t that far – maybe 80 miles – and I knew the area well enough so I just resorted to IFR – I F ollowed R oads – although admittedly I didn’t fly low enough such that I could read the motorway signs ;-)

I have not been in this game long enough to be in a position to recount tales of the good old days. So admittedly, my non-GPS flying skills are probably not as good as they could be. Although I do leave the iPad & Co out of sight (but within reach) on flights over familiar terrain ocassionally (and even on normal flights, I keep the lid of the iPad kneeboard closed and only take peaks every few minutes to cross check)

Now, there are two scenarios:

• There is a general, known (pre-flight) GPS outage. In this case, of course my flight preparation would look much different from my standard SkyDemon way of doing things. I would purchase the paper map, get some navlog and probably brush up on some of that stuff beforehand. Anything else would be negligent, obviously.

• The other scenario is a sudden in-flight GPS outage (for that matter, same as failure of your GPS receiving device/s). Short of a concurrent radio failure, I fail to see the issue. Obviously, one would swollow one’s pride and call up the most appropriate radio station. Even if I were still well aware of my situation I would let them know what the situation is so they can have an extra eye out just in case I get lost later. There is absolutely no good reason not to do that. That’s what they are there for, after all. In fact, any time I see DFS people speak publically, they actively try to encourage (private) pilots to let them know about any problem early on. Too often, people are too proud and think they got it all unter control – until they don’t.

Of course it’s better to know your position at all times – even if your plan A device has failed and you’re operating in a “back to roots”-mode. But that is a matter of airmanship rather than live or death, IMO, at least in territories such as most of Europe where ATC can help out.

Peter wrote:

You will get zero credit just because GPS was down.

Sorry, I thought that you meant that you would get zero credit just because GPS was down. I now understand that you were saying something different.

Peter wrote:

All designed to leave a very foul taste in the pilot’s mouth.

I think you might be surprised by the design process and how much thought went into it. The idea is to educate and prevent future occurrences. Foul taste does not come from the outside. The plan is to get better compliance without increasing prosecution.

I guess that there will always be those who object to being corrected and re-educated, however you do it. They are presumably the ones to reoffend and to end up with more draconian action, such as suspension and prosecution.

There are plenty of voices calling for such actions, on a first offence, but the CAA is doing it’s best to take action which is corrective not punitive.

I don’t think you read that thread, Timothy.

denopa wrote:

What items have you come to feel you can leave at home but would be necessary in such an event?

None. I usually have paper charts (admittedly often outdated ones, but then the mountains tend not to move too much, even here on the ‘Shaky Side’…) on x-country flights and at least around the US there are plenty of VORs that will get you there and back. Also the ForeFlight maps by themselves don’t depend on GPS, so an up-to-date version is always in the cockpit. The biggest issue might actually be to land at the correct airport, there are several areas that have multiple airports in close vicinity to each other and if unfamiliar with the area, this can be a bit of a challenge. Locally, navigating the L.A. airspace would prob90 be somewhat difficult if you’re not local, if you live and fly here you know the landmarks.

For what its worth I’ve yet to hear of any pilot, car driver or pedestrian in the western US who has lost GPS reception in relation to this event.

On one day this weekend, I’ll be making a 350 mile out and 350 mile back flight and while GPS/Foreflight will be used, two devices simultaneously, I’ll also be following roads. I won’t be in contact with ATC and if I were to lose GPS I’d likely land someplace and figure out why. I have charts in both paper and electronic form (x2), regardless of GPS reception. If I were lose GPS reception and call ATC just to let them know, I imagine they’d say “Radar contact 15 miles west of Place Name, tell me again why you called” or words to that effect. Maybe if you were in very dense Class E airspace surrounded by Class B it would be reasonable to ask them for a vector clear, and in that instance I might be taking to ATC. If a NOTAM were in place I’d certainly be wary of potential GPS failure in planning my route.

I’ve met two pilots in the US who admitted to having entered Class B or C without a clearance, and subsequently had to discuss it with FAA. I have met no pilots who have had a certificate action or fine in relation to entering airspace.

Actually I started this thread because of a post on MMOPA, a pilot lost all GPS for the entire flight. He was aware it might happen and was prepared though.

What did he do?

I really think a fallback to map reading without busting CAS in places like the southern UK is really hard except in the most trivial circumstances, in good visibility, and preferably coupled with local knowledge. That fact that it works in PPL training is simply because PPL training is rigged to contain only easy flights for the mandatory solo portions. The objective is not to train pilots, like it is in e.g. an air force where you don’t want to lose a pilot nor a $50M plane.

I could do it flying Shoreham to Lydd – but only because I know that if I keep below 5500ft and stick to the coast (which is a blindingly obvious landmark anyway) I cannot bust any CAS. I could equally navigate Shoreham to the Scilly Isles but would bust CAS around Southampton etc unless I was really really careful. Across the country, inland, it gets much harder to do it with a high degree of confidence.

That’s why – and I know this is completely off topic now – I have multiple GPS receivers. One of these is far more likely to fail than the GPS system. I think if I was doing an inland VFR OCAS flight and all of them failed, I would be in deep $hit very fast. I would have to sort out some VOR/DME fixes, but the workload would go through the roof and that is with a working autopilot.

This is one reason I don’t fly non-radio through the airspace of a radar unit like Farnborough. I call them up. They can then see me and generally leave me in peace. It is London Info (no official radar) who don’t leave you in peace and keep asking for estimates to places which, ahem, you read off the GPS If the GPS was totally lost I would just tell them and ask for help.

Under Eurocontrol IFR, the “official” fallback for non-INS traffic is indeed ATC. This was stated at a Eurocontrol nav conference I went to in 2008. For INS and similar high-end traffic they will be supporting DMEs and even said more will be installed.

He was IFR at FL200+ (Piper M600). Dead reckoning and VOR fixes.

On top of my list above, TAWS and ADSB traffic disappear, as well.