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Need to be sure of your avionics doing this

Even knowing it would end happily I found that a butt clenching approsch

EHLE / Lelystad, Netherlands, Netherlands

And no WAAS / SBAS in sight!

So, what was the VNAV/LNAV guidance?

Inertial with DME/DME corrections?

Administrator
Shoreham EGKA, United Kingdom

I watched this video a couple of weeks ago and was amazed to see the aircraft entering IMC so close to terrain. I tried to figure out the flight path and is must be something like this:

There is no published approach that looks like the path they have flown. To me it seems they were cowboying to get the most stunning video shots
I can’t imagine that there is a need to do a 180 on a IAP so close to terrain.

A Transavia 737 captain told me last year they do use PRNAV (GPS) on approaches to Innsbruck in IMC and close to terrain.

Being able to navigate 0.3NM accurately and having TAWS make it possible to do this kind of crazy stuff…

I too could not make any sense of the flight path in that video. All one can be sure of is runway 05, because they arrived over the big lake. But the right turn they did is not as per the chart.

Administrator
Shoreham EGKA, United Kingdom

PRNAV is not a specification that is used in the US. We use RNAV including RNAV 1 and 2 for terminal and enroute navigation; and RNAV approaches including LNAV, LNAV/VNAV, LPV, and LP. There are no unique restrictions on a C150 for the aforementioned specifications. RF is part of the RNAV specification, but is not currently approved.

Also used is RNP for authorized users, RNP .3 down to .1 for approaches and with or without RF. This is mostly used by some airlines.

KUZA, United States

No, they were no cowboys!
They flew the then standard (for approved operators) RNAV (RNP) RWY 05 letdown (see page NZQN AD 2 – 45.1 in QUEENSTOWN). They were “visual” until passing FRNKK, entering cloud in right turn on the way to the final fix at QN012. They passed FAF in cloud, still in the right turn, at the altitude of 3040 feet (i.e. on the Glide Path). They became visual, with runway in sight, just past QN008. If they were flying, as I would assume, to the RNP0.15 standard, they were then some 1000 feet above their Decision Altitude for this RNAV (RNP) approach with the baroVNAV guidance.

These RNAV (RNP) approaches has now been withdrawn:

B5780/12 NOTAMN
Q) NZZC/QPIAW/I/NBO/A/000/999/4501S16844E005
A) NZQN 1302061100 C) PERM
E) REF AIP NZQN AD 2-45.1
QUEENSTOWN RNAV (RNP) Z RWY 05:
PUBLISHED IFR APCH PROCEDURE COMPLETELY WITHDRAWN

REF AIP NZQN AD 2-45.2
QUEENSTOWN RNAV (RNP) Z RWY 23:
PUBLISHED IFR APCH PROCEDURE COMPLETELY WITHDRAWN

and replaced with RNAV (RNP) Y RWY 05 & 23 approach procedures.

Last Edited by ANTEK at 15 Nov 14:30
YSCB

PRNAV is not a specification that is used in the US.

There is however a procedure whereby an N-reg aircraft, wishing to fly in the atmosphere owned by the European “Union” needs to get a PRNAV LoA from the FAA.

To get this, one needs to write to the NY IFU, with various supporting documents. The last I have heard is that they take a year or so to come up with them.

Also the procedure has varied over time. One pilot I know, with a well equipped twin, basically buried the FAA under so much paperwork (supporting his qualifications and his plane’s capabilities) they probably just gave it to him rather than read through it all That route is AFAIK now closed. Similarly a small number of G-reg owners got the stuff from EASA, in the early days before EASA got organised to make it a proper job creation scheme and a Major Mod.

Also the GTN Garmin boxes, and the GNS “W” boxes, now come with a “PRNAVAFMS, which I think avoids the NY IFU route altogether, although I saw a post elsewhere (in a private forum) disagreeing with that (stating that the FAA LoA is still needed) but no information supporting that position was supplied so I don’t know either way. My KLN94 can’t get the FAA LoA for other reasons so I have no need to know this myself.

There are no unique restrictions on a C150 for the aforementioned specifications.

That I think is correct, even though the (very few) N-reg pilots who have actually followed this route did so with much more fancy aircraft and equipment. Obviously a C150 would be a chocolate teapot for European IFR.

Administrator
Shoreham EGKA, United Kingdom

Peter, having the PRNAV certified in the AFMS does nothing to prevent the need for a PRNAV LoA. The LoA applies to the operator and pilot. The equipment and the operator need to be approved in order to get the LoA. IUf the AFMS includes PRNAV that makes it easier otherwise it gets even harder.

EGTK Oxford

Didn’t the UK CAA issue a note some months ago saying that operator approval is no longer needed, for UK airspace at least?

We discussed it here – there is a long PRNAV thread on here.

The operator approval was a bit of a joke – you could get it with a certificate from a day seminar which you attended.

The American King school was also doing a PRNAV operator course for US operators wishing to fly to Europe; not sure if that remains relevant.

I know only two people who actually understand this stuff in detail (the very latest for European airspace) and can write about it in detail, with all the references. One of them is very busy and rarely posts here, and the other doesn’t post here.

Last Edited by Peter at 15 Nov 16:21
Administrator
Shoreham EGKA, United Kingdom

RNP approaches in EASAland require specific operator and flight crew training/approval. Very few airlines have bothered as there aren’t many approaches to justify the ridiculous expense and paperwork. Think of the expense of crew training, sim time, ground school, approvals and so on.

I believe the Faroes are one place that really benefits from the RNP approach, I imagine Innsbruck might too, but can’t think of that many major CAT destinations within europe that might require them.

London area
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