For a bit of additional perspective (commercial jet), the only sensible answer is (A). As mentioned above, a lot of the time the MAPt is too close to the threshold for the given MDA. If I was to arrive at 0.6D, still over 500’ AGL, there is no way I am landing off that approach whilst also keeping my job. Yes, if you arrange to arrive at MDA at the MAPt, you will have a better chance of seeing lights/runway, but is that of any use if you can’t safely land from that point (I appreciate in typical GA types to instruments runways this is more likely to be possible)?
We make very little difference between precision and non precision approaches in this context. Both of them we begin at the FAF and descend on the specified profile until we get to DA/MDA, at which point we are either visual or we go around. MAPt seldom has little relevance. In fact, I believe our chart provider (LIDO) was talking about removing ‘MDA’ from plates and just designating everything as ‘DA’ since for commercial ops there is no difference (CDFA mandatory).
we begin at the FAF and descend on the specified profile until we get to DA/MDA, at which point we are either visual or we go around
@Pirho describes it well, and in terms of a practical test the IR standard is plus/minus 50 feet at each DME mile of the specified profile.
In the real world you would either fly the ILS or RNP at EGHI. EGHI has only come into use again for training as a consequence of the demise of FlyBe (hopefully soon resurrected in a Dash 8 turboprop only business model) and lockdown.
Graham wrote:
I want to fly the approach with an examiner and know what I’m supposed to do.
For noncommercial ops both d’n’d and CDFA are admissible, but – as RobertL18C wrote – CDFA is best practise. (And arguably easier to fly.)
When you brief the approach, you should state that this will be a CDFA. Aside from making clear to yourself what you will do, you will also make clear to the examiner what you will do.
Airborne_Again wrote:
For noncommercial ops both d’n’d and CDFA are admissible, but – as RobertL18C wrote – CDFA is best practise. (And arguably easier to fly.)When you brief the approach, you should state that this will be a CDFA. Aside from making clear to yourself what you will do, you will also make clear to the examiner what you will do.
Thank you again both. This is the information I need – and the follow up question was just to establish what (if anything) needs to be done about the fact that the MDA will not occur at the missed approach point but rather a mile or two before it.
The real world, of course, is something else.
Graham wrote:
The real world, of course, is something else.
What do you mean?
Graham wrote:
The real world, of course, is something else.
Not at all. In a “real world situation”, you would do exactly the same – go around when reaching the (M)DA and you should reach it about a mile before the MAPt.
(In the most “standard” case where the MAPt is at the threshold, the TCH is 50’ and the nominal glidepath is 3°, it will be exactly a nautical mile before the MAPt with a (M)DH of 366’.)
Sorry, I’m not being clear. I mean that in the real world I wouldn’t be flying this approach in the first place – I’d be flying an ILS or the GPS overlay.
I thought it might be useful to list the UK/Channel Islands/IoM airports which currently have published VOR/DME approaches.
I believe these are available today at
Aberdeen
Belfast Aldergrove
Benbecula
Biggin Hill
Glasgow
Guernsey
Inverness
Isle of Man
Jersey
Kirkwall
Manchester
Southampton
Sumburgh
Wick
All have precision approaches, ILS or LPV, except Benbecula where I understand NATS want to turn off the aging VOR but there are technical issues designing a replacement GNSS procedure due to terrain.
Belfast Aldergrove and Manchester even have four each, so these 14 airports have 30 VOR approaches in total.
@DavidC that is useful, thank you!
There does seem to be a push to decommission them, and quite understandable really. However it is not without problems. The IR(R) renewal/revalidation requires a non-precision approach at some point, and in my (our) aeroplane RNAV is not an option (yet).
Flying out of EGLM it is now quite limiting if you consider (a) distance flown just to fly the approach, and (b) the ability to book an approach in advance (i.e. not on the day) with a reasonable certainty that you’ll be able to fly it as planned, and at reasonable cost.
