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PRNAV and PBN

I don’t understand your post, bookworm. I know you know all about this

This is all about the future and what it may bring to shaft us private GA IFR pilots if the regulators don’t think it through properly.

There is currently no (?) enroute PRNAV-only airspace. Last I heard, there was talk of (for example) the London TMA being PRNAV only, but there was a proposal to exempt traffic unless operating to/from Heathrow, Gatwick, Luton, Stansted, City, which would be fine because no GA goes there anyway (except when on fire). I don’t know where this currently stands; the reply I got from NATS was a “zero-information” corporate sort of reply.

As regards PRNAV airports, I am not all that bothered because there are loads of those already but they offer non-PRNAV procedures and/or they make it very obvious they couldn’t care less. And a prosecution, or an insurance invalidation, is IMHO impossible in those circumstances because as the Captain you can say afterwards you intended to fly Procedure X (non PRNAV) but for operational reasons decided not to.

I would guess that most ATOs today include B-RNAV in their IR courses,

Not mentioned in the JAA IR I did in 2011. One of the lecturers saw my TB20 and asked “gosh, that’s a nice new plane, have you got a KNS80 in there?”

since in much of Europe the rating would be useless without it.

True, but BRNAV/PRNAV all fades into irrelevance when you fly with GPS navigation. All that RNAV5/RNAV2/RNAV1 stuff is just daft, with GPS.

Maybe Swedish IR ATOs do train pilots to actually fly IFR in Europe? I wonder where the syllabus and the question bank comes from?

They sure don’t in the UK. The IR course uses old Jepp airway charts and how to work out a route on them alone. That has not worked since probably about 1995.

Administrator
Shoreham EGKA, United Kingdom

Now you’re talking about different things…

- How to get the necessary approval to fly in (B/P)RNAV airspace.
- Whether RNAV5/2/1 etc. are meaningful distinctions given the GPS accuracy.
- How to find a route that Eurocontrol will accept.

Actually, the RNAV5/2/1 or B/P-RNAV distinctions are meaningful IMHO. It is not just about the fixing accuracy, but about flying the aircraft to the given precision. If you mess upp with the FMS on a B-RNAV route, you are unlikely to stray very far before you notice and correct (unless you’re asleep). If you do the same thing on a P-RNAV route you may find yourself outside protected airspace real soon.

The RNAV manual on the PPL/IR website makes clear the difference in theoretical knowledge between B-RNAV and P-RNAV.

ESKC (Uppsala/Sundbro), Sweden

If you mess upp with the FMS on a B-RNAV route, you are unlikely to stray very far before you notice and correct (unless you’re asleep). If you do the same thing on a P-RNAV route you may find yourself outside protected airspace real soon.

Is there any evidence for that, in reality, that the “protected” airspace is narrower? I have never seen any example of that. The LTMA, for example, is huge and is big enough to contain all the various published sids, stars and missed approach procedures. It has hardly been revised in many years and it will never shrink, not least because – like all European CAS – it gets traffic from every 3rd World airline which has not been actually banned by the EU.

PRNAV is RNAV1.0, laterally. One well known UK pilot had a flight session with a well known NATS/CAA guy a few years ago, and proved to him that hand flying to RNAV1 requirements was entirely feasible. Any terminal procedure in CAS has a huge protected area around it. Obviously there is the matter of pilot workload but if you assume that a pilot will screw up seriously enough then you need to ban all single pilot IFR / non-autopilot IFR / etc.

the difference in theoretical knowledge between B-RNAV and P-RNAV.

Yes, but that manual (which we have on EuroGA too, with the author’s permission), is a tour de force in IFR terminology, written by a self confessed total “IFR anorak”

Administrator
Shoreham EGKA, United Kingdom

and it will never shrink

We shall see whether the results from FASVIG actually achieve anything.

There’s a lot of outdated procedures which has influenced the design of the LTMA.

Last Edited by James_Chan at 02 Jan 15:35

Neither B-RNAV nor P-RNAV are included in the EASA IR syllabus.

Last time I checked, morse code wasn’t part of the EASA IR syllabus, yet you still need it to decode station identifiers for NDB, VOR, DME and ILS. Yet noone I know suggested one should get additional training at an ATO to be allowed to use these stations…

It is not just about the fixing accuracy, but about flying the aircraft to the given precision.

I agree that the error that completely dominates the sum of all errors is the flight technical error. However, Garmin made a study for the FAA where average pilots were tasked to fly a complex sequence of RF (radius to fix, i.e. curved) legs with fairly basic equipment (GNS430W, HSI) and without any specific training, and they were able to achieve a 2sigma accuracy of +-0.2NM. Plenty good enough for PRNAV, and it’s IMO safe to assume that flying straight and level is even easier than flying complex curved approach sequences. So there is strong evidence IMO that this whole extra training for PRNAV is not needed.

LSZK, Switzerland

So there is strong evidence IMO that this whole extra training for PRNAV is not needed.

I haven’t taken any PRNAV training, so I can’t say for certain what’s involved, but my distinct impression is that it doesn’t at all focus on flight training such as following a CDI. I’ve also read the Garmin study and I agree that any decent IR pilot should be able to fly both PRNAV and RNAV approaches without problem. The problem is not in manoeuvring the aircraft but in flight management and planning – knowing what to look out for, what checks to make etc. and that’s what I understand that the training is about.

ESKC (Uppsala/Sundbro), Sweden

The problem is not in manoeuvring the aircraft but in flight management and planning – knowing what to look out for, what checks to make etc. and that’s what I understand that the training is about.

Have you ever seen an EASA theoretical syllabus that had anything to do with reality?

I recently did the infamous FOCA RNAV GNSS Approach gold plated course. It’s assorted bits of trivia (like what all the acronyms stand for), and quirks of the G1000 (which I don’t own), that very often aren’t applicable to say a GTN. A bit like the IR syllabus that teaches idiosyncrasies of the B727 avionics, which not many private pilots will ever do.

Many here have a SEP class rating, that means they are trusted to read the AFM themselves before they fly a new type. So why can’t we trust them to read the AFMS and the GNSS kit manual while they’re at it?

LSZK, Switzerland

Many here have a SEP class rating, that means they are trusted to read the AFM themselves before they fly a new type. So why can’t we trust them to read the AFMS and the GNSS kit manual while they’re at it?

People are not trusted to read the AFM to understand how to operate retractable landing gears or constant speed props if they haven’t done before. Differences training is required. Same thing for EFIS. I don’t really see why RNAV should be any different.

As someone who learned to fly at a time when RNAV for GA meant KNS80 and for airlines meant INS, I can say that although it is certainly not difficult to use a typical GPS RNAV system, from a flight management perspective it is quite different from using VOR/DME. There are pitfalls which are not obvious. Certainly the difference is greater than between fixed and retractable landing gears!

ESKC (Uppsala/Sundbro), Sweden

The problem with that line of argument is that it leads to a “type rating” course for every significant new instrument in the cockpit.

In the commercial world, that is indeed what happens – with some curious exceptions like the CJ1-CJ4 being on a common TR (AIUI).

In light GA we have enjoyed a relative freedom and trust to use our brains to not fly until we have done some “research” on which knob does what.

One could argue it both ways (modern avionics are certainly not trivial) but if I was spending money and effort on anything, I would start by

  • improving the PPL syllabus so the pilot can fly from A to B (which here in the UK they mostly can’t)
  • improving the IR syllabus so the pilot can fly from A to B under Eurocontrol IFR (which under JAA/EASA he can’t – he won’t even know how to file the flight plan)

The training system is mostly useless for its advertised purpose and only those who get “hooked” and are really keen to hang in there and who put in the extra effort to learn the extra stuff will remain in there and enjoy it.

There are courses for advanced GA but you have to find them.

Administrator
Shoreham EGKA, United Kingdom

I agree with Peter. I always cringe when reading that even pilots call for more regulation and gold plating, especially when it is about a subject like GPS, where authorities have been known to have no idea about how that works in practice.

Mainz (EDFZ) & Egelsbach (EDFE), Germany
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