gallois wrote:
Airborne _Again wrote: “Do you really think that this is the only important thing to learn about PBN?”
Perhaps not, but I really don’t remember learning anything I didn’t already learn during my IR course so the PBN part didn’t need a book or an exam. Actually I didn’t have either in getting my PBN and wouldn’t really have known I was doing anything extra. What did you learn or teach when you got your PBN.
Some things that I found non-obvious when I learned about RNP approaches.
When you’re making an ILS approach, you know that you should check things like
What checks do you need to do on e.g. an LPV approach?
If you go missed on an RPN approach, the waypoint sequencing will suspend. When should you unsuspend it if
Is pressing the suspend button and when really anything to do with PBN or have we already learnt it when we learnt and ILS approach with the G1000 etc.
PBN is a concept overlaid on RNAV approaches in order to make a more open sky. It is more an evolution of RNAV 1 and PRNAV and GNSS and now RNP. IMO it is not something worthy of a large textbook reiterating many of the things that most pilots learnt when doing difference training to glass cockpit or to be more correct modern GNSS equipment and certainly for me, not the subject of something that should be treated as a formal exam.
Yes we need to know about RAIM, and SBAS needing no RAIM. About when LNAV + V can and should not be used and why it is not safe to use as a precision approach.
The difference between LPV as a precision approach and LPV as.a non precision approach is another.
There are other things but they are all things we would normally read up on, if you took your IR before PBN came into being, before a revalidation. I don’t object to the sort of questions about the.“susp” button and when it should or should not be pressed in the briefing with an examiner before a revalidation. If you are going.to use equipment suitable for PBN in airspace suitable for PBN you should know what it is and how to use it, but some seem to make a bigger issue of it than it actually is.
Airborne_Again wrote:
What checks do you need to do on e.g. an LPV approach?If you go missed on an RPN approach, the waypoint sequencing will suspend. When should you unsuspend it if
The missed approach starts with an immediate turn at the MAPt?
The missed approach starts with a turn at a particular altitude?
Neither of the above?
But this is ‘how to use your avionics’ more than anything else. It’s very difficult to ‘train’ it in a sensible and standardised way because everyone is using different boxes.
As I said before, ‘how to use your avionics’ is best addressed by playing with it, on the ground if necessary, and reading the manual. PC-based simulators for most boxes are also available. If you need an instructor to show you round some software, then….
The video posted by @RobertL18C was extremely good but makes it clear that, as @gallois says, PBN and RNP are completely arbitrary constructs designed to deal with the fact that many larger aircraft don’t have fully-GPS-based navigational systems. It would have been far clearer for everyone if they just referred to the whole thing as ‘GPS approaches’ and added a rider that you could also fly GPS approaches if you had some non-GPS setup that could be shown to give acceptable accuracy.
But as I said, there’s an industry incentive to make it complicated rather than simple.
Graham wrote:
But this ‘how to use your avionics’ more than anything else. It’s very difficult to ‘train’ it in a sensible and standardised way because everyone is using different boxes.
It is not. These questions do not relate to particular pieces of avionics but to the TSOs that determine how the avionics work. The answers to the questions are the same regardless of the kit you use.
gallois wrote:
Is pressing the suspend button and when really anything to do with PBN or have we already learnt it when we learnt and ILS approach with the G1000 etc.
Yes it is. Even with a G1000, you can fly an ILS without any use of the procedure database or the PBN functions of the avionics – it is only a convenience. When you fly an RNP procedure you have to use both.
PBN is a concept overlaid on RNAV approaches in order to make a more open sky. It is more an evolution of RNAV 1 and PRNAV and GNSS and now RNP.
Technically you’re right, but as a concept, the idea of PBN is entirely different. The idea is to create a set of procedures and rules which are independent of the kind of particular navigation equipment. E.g. RNAV 1 work the same whether your navigator is based on DME/DME or GPS. There is now also the Performance-Based Surveillance and Performance-Based Communications concepts which serve the same purpose.
Also, PBN is not an evolution of RNP. RNP is a class of performance specifications within PBN. (Just as RNAV is.)
IMO it is not something worthy of a large textbook reiterating many of the things that most pilots learnt when doing difference training to glass cockpit or to be more correct modern GNSS equipment and certainly for me, not the subject of something that should be treated as a formal exam.
We’re not arguing the size of the textbook. We’re discussing if you need PBN training at all (or longer than 5 minutes).
Yes we need to know about RAIM, and SBAS needing no RAIM. About when LNAV + V can and should not be used and why it is not safe to use as a precision approach.
The difference between LPV as a precision approach and LPV as a non precision approach is another.
There are other things but they are all things we would normally read up on, if you took your IR before PBN came into being, before a revalidation. I don’t object to the sort of questions about the.“susp” button and when it should or should not be pressed in the briefing with an examiner before a revalidation. If you are going.to use equipment suitable for PBN in airspace suitable for PBN you should know what it is and how to use it, but some seem to make a bigger issue of it than it actually is.
If think we’re already well beyond 5 minutes with the points you make. In any case, it should be easy for you to answer my questions, shouldn’t it?
Never press SUSP until you have passed the MAP unless the plate says that turning before the MAP it is permitted.
Yes you can fly an ILS with no reference to PBN or RNAV but if flying with a G1000 on an ILS the susp button was there long before PBN came into being.
I don’t think we were discussing whether we need PBN training at all. Didn’t this merged section of the thread start about mandatory training and test/exam for PBN in the ROI.
I hope I have been clear, I am not anti PBN training or questions based on PBN at revalidations, but that the general principles can be gathered without the necessity for a separate course at an ATO or an exam.
In training within an ATO for an IR, CBIR or differences, PBN will be integrated with the other learning.
I don’t usually join these discussions as I don’t like getting shot down for lack of detail.
However Airborne_again is completely correct.
Having just read this dicussion from beginning to end, it is clear to me that the main details and understanding of PBN is being overlooked by some.
It is not navigator specific information.
Clearly Gallios has taken steps to understand more than some, and that is probably enough, but the point I’m making is that some don’t seem to know what they don’t know.
I’m no expert and often struggle to remember some of the detail but when reading this thread I can’t help feeling that some (possibly very small) amount of study or training IS required.
That may not apply to everyone on here but I bet it does apply to many who are just ‘having a go’
gallois wrote:
The difference between LPV as a precision approach and LPV as.a non precision approach is another.
Are you sure that LPV is a precision approach? I always thought that this is APV, 3D approach.
Ha according to PBN manual an LPV approach with a DH below 250’ is considered a precision approach.
LPV is an APV (approach with vertical guidance) however so is an LNAV + V the difference between the 2 is (short version) that like an ILS the LPV is angular both vertically and horizontally which means they converge to a point in the same way a a VOR does. LNAV + V works like the magenta line.on the GPS and do not converge, therefore they are not as accurate at lower MDH/DH and the vertical path needs barometric pressure which the LPV like the ILS glide slope and therefore loses accuracy with temperature. This I will admit is easier to explain with an image.
I should mention that some talk more of 3D and 2D approaches rather than APV or non APV.
The reason I wrote “Ha” at the beginning was not addressed at you but I was beginning to wonder if I was going to be hoisted by my own pétard and prove the point that a special ATO PBN course is necessary.
Airborne_Again wrote:
When you fly an RNP procedure you have to use both.
Do you?
What’s stopping you individually loading the waypoints into the world’s most basic GPS and just flying from one to another, at least for LNAV? You don’t even need to load them. For a simple LNAV like e.g. EGBJ RNP Rwy27, you know that you have an IAF at 10nm long final on a 264 course so you just fly over that at 2,500, stepping down to 2,000’ at a 5nm final, 1,250’ at 3nm and 510’ at 1nm, with the minimum being 600’. You don’t need to load the procedure in the box to do this (practically, I make no comment on legally.)
Unsuspend in the missed approach or don’t – it’s up to you – the aircraft will fly the same and it’s the control surfaces that dictate its path through space, not which mode the box is in. What you need to do is fly the procedure on the plate. How to make your box display the appropriate things at the appropriate time to help you best do that is a case of ‘how to use your avionics’. The fact that box manufacturers may have standardised on certain terminology and functionality is neither here nor there.
Maybe I look at it slightly differently because nearly all my IFR flight is in an aircraft without an autopilot. Hence I’m less fussed about what the box is doing because it isn’t coupled to what the aircraft is doing. If I’m following my plate instructions and climbing straight ahead to 1,500’, then into a climbing right turn to 2,800’ to return to some point in space then it isn’t necessarily essential to me that the box is playing along with all this. Having gone missed in the first place (which for someone with my operating profile is a highly irregular occurrence) I’m going to be concentrating on flying the aeroplane and then pondering some bigger questions – like whether to divert or have another go. Exactly what mode the GTN might be in, or what button it might be optimal to press at what time, will be a long way down my list of priorities.
