Peter wrote:
I really don’t want to be over-assuming something but it is well known that the UK IR/ATPL training business deliberately flies with an out of date GPS database, to make sure that the GPS cannot be used in the test. Then, they don’t need to teach it. I have this from a source who is extremely familiar with the UK scene.
This was definitely not the case where I did my training (I was trained to GPS approaches). Part of my check was checking databases valid.
Wouldn’t that mean that the GPS then can’t be used for airways too ?
Noe wrote:
Wouldn’t that mean that the GPS then can’t be used for airways too ?
It can — for RNAV 5 (BRNAV) you don’t need a current database.
Wouldn’t that mean that the GPS then can’t be used for airways too ?
Of course you cannot usefully fly without an IFR GPS, but I think the point here is that IR training, UK at least, is done at low levels, occassionally popping into CAS. The training and test routes are standardised. Most of it is done c. 5000ft. You don’t do a proper Eurocontrol flight, FL100-150 etc, from say Bournemouth to Prague, or even from Bournemouth to Le Touquet (not permitted to train or test outside UK airspace). The fact that the candidates cannot fly usefully afterwards doesn’t bother anybody because they will never have to; they sit around until they get an airline RHS job and then they drop into a system where everything is taken care of.
It’s only private pilots like us who need to be taught something actually useful 
for RNAV 5 (BRNAV) you don’t need a current database.
Whether flying with an expired DB is legal depends on the wording of the GPS AFMS…
Peter wrote:
You don’t do a proper Eurocontrol flight, FL100-150 etc
After all these years I still don’t see why you distinguish between IFR and “Eurocontrol IFR”. Maybe this is a typical UK topic but everywhere else, IFR is IFR. Whether it is coordinated and billed centrally (Eurocontrol) or not does not make the least bit of a difference. You file a flight plan along an apporved route and once this plan is accepted you go flying. Whether that is at 4000ft or at 40,000ft makes no difference at all.
Peter wrote:
…not permitted to train or test outside UK airspace…
Again, a peculiarity of the UK. At least one thing that will not be changed by Brexit 
Peter wrote:
Whether flying with an expired DB is legal depends on the wording of the GPS AFMS…
I think that database currency thing of BRNAV comes from the fact, that GPS is only one of many navigation methods which can be used to achieve the required precision (or “performance” as it is called nowadays). The classic VOR-DME RNAV equipment is also BRNAV capable and usually has no database at all. Therefore they can’t enforce a (current) database for GPS receivers. For higher levels of RNAV (PRNAV or RNP1 or whatever) a certified and current database is a requirement and and self-entry of coordinates by the end user is verboten.
After all these years I still don’t see why you distinguish between IFR and “Eurocontrol IFR”. Maybe this is a typical UK topic but everywhere else, IFR is IFR. Whether it is coordinated and billed centrally (Eurocontrol) or not does not make the least bit of a difference. You file a flight plan along an apporved route and once this plan is accepted you go flying. Whether that is at 4000ft or at 40,000ft makes no difference at all.
Sure; it is to do with the service you are getting.
In the UK you can do IFR OCAS, non-radio, and this means all sorts of things are possible. It is mostly Class D+G. The FTO industry operates mostly in that environment. The equipment carriage requirements for that are very basic.
What I call “Eurocontrol IFR” is usually in CAS (the only significant exceptions are in Scotland) and you need BRNAV as a minimum. In the UK this is also mostly Class A.
I think that database currency thing of BRNAV comes from the fact, that GPS is only one of many navigation methods which can be used to achieve the required precision (or “performance” as it is called nowadays). The classic VOR-DME RNAV equipment is also BRNAV capable and usually has no database at all. Therefore they can’t enforce a (current) database for GPS receivers. For higher levels of RNAV (PRNAV or RNP1 or whatever) a certified and current database is a requirement and and self-entry of coordinates by the end user is verboten.
I think that would be true if you were carrying an FM immune KNS80.
Peter wrote:
I think that would be true if you were carrying an FM immune KNS80.
Yes. Or LORAN equipment where there are still transmitter chains. Or INS.
I thought the only legal means of BRNAV compliance are
Was any LORAN box ever certified for this?
Peter wrote:
I thought the only legal means of BRNAV compliance areFM immune KNS80 (useless in reality)
an IFR GPS
INS (not applicable to GA)
DME/DME as well. Which is what a lot of airliners use.
Only in conjunction with INS, AFAIK. That is what airliners use. They use DME for fixups of the INS. Modern ones also use GPS for that.
I don’t think there is a DME/DME product which purely dead-reckons using just software (kalman averaging of past track and speed) and periodically uses DME fixups. That would a nice product for GA. You would just need a remotely tuneable DME. I don’t think anybody would buy it though because nobody believes GPS will fail, in any scenario in which GA will still be permitted.
If I had a homebuilt and wanted to throw some money away, I would put this in
Airborne_Again wrote:
DME/DME as well.
Yes, but I don’t think it works without a waypoints database. At least ours failed together with the GPS after a failed database update…
