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PRNAV and PBN

This document

has just came out here in the UK.

I may be missing something, but doesn't it just say what everybody has known for years i.e. that to fly a PRNAV procedure, or in PRNAV airspace (if that ever comes to exist it will wipe out 99% of GA activity there) then you need PRNAV kit, an AFMS for it, and crew "training".

A few years ago, some people got in under the wire with EASA as a Minor mod, and some more got in under the wire with the FAA by burying them with papers showing how well equipped their plane was and how many qualifications they had, but these days it's hard work.

Airports couldn't care less about non-PRNAV traffic flying their "PRNAV" procedures, thankfully.

One could spend well into 5 figures getting this paperwork. There are bigger fish to fry for "European IFR", which in the never ending game of trying to comply with stupid regs as most pilots do, are more operationally relevant, e.g. 8.33.

What do other people here plan to do about this?

I also wonder how many bizjet pilots or owners are concerned about PRNAV.

Administrator
Shoreham EGKA, United Kingdom

I just received an FAA PRNAV LOA yesterday. It took time and some docs but no money other than paying for the King Schools course which took all of 20 minutes to complete.

But with the 650s I had all the right stuff in the AFM.

Sadly I gather that for N reg the sequester situation is going to make an LOA even slower to obtain. Mine took 5 months.

EGTK Oxford

To get FAA certification done, one needs to have "contacts". The best thing is to have somebody in the USA who can sit down at a desk with an FSDO inspector. That is how I got my SN3500 and KLN94-AFMS jobs done (the first was in fact the inspector himself; now retired). But I no longer have those contacts so any alterations I do will have to be either STCd (which for the TB20 means an AML STC, most likely) or reconfigured to be Minor.

I understand the Frankfurt FSDO may be able to do this stuff.

The NY IFU has had the most bizzare issues for years. They have driven countless people around the bend. There is something very strange going on in there. It's looks like it is an FAA "outpost" which has gone out of control. When I phoned them about the SN3500 job, they said an EHSI it is an EFIS product and cannot be done without an airframe specific STC. The bloke I spoke to spoke to some colleagues in his office and they agreed. It's 100% bull, but if you didn't know better you would go along with it. There are also major issues going on in there which concern matters other than certification. Of course all this suits some European interests...

Administrator
Shoreham EGKA, United Kingdom

A GNS430W installation is either approved for PRNAV according to the AFMS or can be approved for it.

So only the crew is a problem. The German CAA lets you do a self declaration about your PRNAV proficiency. If it stays that way, I don't see an issue.

Pre GNS430W GPS aren't LPV capable which will become a standard requirement in the near future for sensible IFR flying.

Not sure if I'm missing something here, but the jet I fly complies with TGL 10 and the PRNAV training is accomplished through the Type Rating. So, from what I know at the moment it's not an issue. I guess if you want to fly your TB along the same lines then you need to get the kit, have it approved and then get appropriate training. A boring CBT no doubt.

ESSB, Stockholm Bromma

Yes the GNS boxes (not just the W ones) and GTN boxes are PRNAV approvable.

The GTNs come with an AML STC which includes the PRNAV AFMS so there is nothing to do there. A huge coup for Garmin.

So only the crew is a problem

But you can solve anything with loads of money, can't you?

It will be many years before LPV is operationally relevant where I fly. Most airports I fly to need to (out of the UK, or back to the UK) have Customs and most of them have an ILS, or some other IAP. LPV would be nice but I won't pay the money for the huge upgrade - GPS, MFD, a big rewire.

The German CAA lets you do a self declaration about your PRNAV proficiency

That's interesting...

Not sure if I'm missing something here, but the jet I fly complies with TGL 10 and the PRNAV training is accomplished through the Type Rating. So, from what I know at the moment it's not an issue. I guess if you want to fly your TB along the same lines then you need to get the kit, have it approved and then get appropriate training. A boring CBT no doubt.

Complying with TGL10 (a vague reg which has been interpreted by different people in different ways, some of them even openly disagreeing at a Eurocontrol conference I went to) is one thing, but you also need the AFMS saying the aircraft complies.

At one stage, a few years ago, the UK CAA insisted that you need an auto slewing course pointer (i.e. an EHSI or equivalent), but after some flights with a very motivated pilot (who showed that one could fly the accuracy entirely by hand) they backed down. The CAA then reversed that position (I spoke to the CAA man himself) but they reversed it again a bit later...

However one reading of TGL10 is that just having a moving map GPS makes you compliant.

The whole of PRNAV is IMHO bunk, because it's easy to get approval for a GPS/RNAV approach which is equivalent to RNP 0.3 while PRNAV is RNP 1.0... I reckon PRNAV is a work creation bandwagon which got kicked off when a load of people were looking for a bandwagon to jump on. Any plane with a half modern GPS, autopilot coupled in NAV mode, can fly to the required accuracy. The issue then comes down to whether the procedure is in the GPS database; the older units don't have them. Some (KLN94 e.g.) have the individual waypoints so you can still load the same flight path, but that isn't strictly legal.

The killer for GA will be PRNAV enroute airspace, but currently there isn't any I know of.

Administrator
Shoreham EGKA, United Kingdom

What do other people here plan to do about this? I also wonder how many bizjet pilots or owners are concerned about PRNAV.

Certification of aircraft and crew is under way within our company. I was asked by our head of training to prepare and conduct the necessary training for our crews which I did with a first group a few weeks ago. A supervisor from our authority was also present during that seminar and was pleased with what he heard so it looks as if we will get out PRNAV authorisation soon.

As of now, there are very few airports where PRNAV is already mandatory and I do not think that this will change in the near future. Among them are Amsterdam and (soon) Munich. Therefore I don't really think that PRNAV will be of much concern to many private pilots in the next couple of years.

EDDS - Stuttgart

The whole of PRNAV is IMHO bunk, because it's easy to get approval for a GPS/RNAV approach which is equivalent to RNP 0.3 while PRNAV is RNP 1.0.

I don't agree. Look at the tolerances of enroute BRNAV and consider that every airplane only has the accuracy of BRNAV. That requires a lot of tolerances in the system and imposes restrictions on routing regarding obstacles, separation, etc. Approach and enroute have always been two separate things. With today's GPS technology (actually even yesterday's) much better accuracy is possible so it's a logical step to require better accuracy of all airplanes.

However, there is no need to turn this into an administrative hell. They should just define some criteria that are easy to verify.

Look at the tolerances of enroute BRNAV

BRNAV (RNP 5.0) goes back to the days of VOR navigation - 30-40 years ago. It means nothing in the modern era. Nobody has been flying IFR to BRNAV accuracy for many years.

consider that every airplane only has the accuracy of BRNAV.

That's not the actual case however. BRNAV means within 5nm of the programmed track.

Administrator
Shoreham EGKA, United Kingdom

That's not the actual case however. BRNAV means within 5nm of the programmed track.

Yes, and clearances/airways/procedures have to be designed with this allowed error in mind. If you restrict that to 25% of the error, then you can design much tighter airspaces. Sounds like a good thing. You can't just say "well, nobody is really 5NM off, so it doesn't matter" but you have to assume that they are 5NM off until you require them to have better accuracy.

Maybe you can replace your KLN94 with this one if it gets P-RNAV approval?

There are IFR aircraft with this device as the basis of their RNAV capability and a handheld GPS to do the actual flying.

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