The process of calculating your DH/MDH for an instrument approach is as follows:
As per point (3) you take into account he System Minima based on the table in the image above.
What then is the intention of the following Runway Type Minima?
I can’t figure out when this would have any impact as surely you’ve already factored this in by taking into account the System Minima. What am I missing?
Well, AFAIR all different runway types differ in terms of paint job, lighting and obstacle survey.
Sometimes if you have an ILS on a runway without a full obstacle survey that is required for PA approaches (or it has expired), then the AIP plate will just say “OCH xxxft” and if that is below 200ft, then you might think that you could go down to 200ft, but they make a point that it is not correct. Jepp should specify the correct one.
I think I follow, but without Jepp how can you tell if the runway is up to PA CAT I standards (and that those standards have not expired)? All the UK plates simply specify things in terms of OCA/H.
There used to be a good app for that called Aeroplus Minima, but it’s not available anymore.
Marsen wrote:
I think I follow, but without Jepp how can you tell if the runway is up to PA CAT I standards (and that those standards have not expired)? All the UK plates simply specify things in terms of OCA/H.
I think that should be in AIP, if it is an NPA runway. And I think it is more of a CYA excercise – I’m not aware of (m)any ILS NPA runways. :)
arj1 wrote:
another thing – this PA/NPA thing is from AMC, not hard law. JFYI.
Good point, what would you say constitutes the hard law for calculating this?
Marsen wrote:
Good point, what would you say constitutes the hard law for calculating this?
If you refer to raising the minima due to obstacle surfaces not being quite appropriate for the approach, there is none.
My main question is how you determine that a runway is a CAT I PA runway or not – there does not seem to be anything in the AIP that indicates this. Yet the regulations refer to it as a decision point in the calculation of minima…
