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Non-CDFA and charts

1. Does anyone know why, even though there is a non-CDFA minima published, no dashed lines (level segment) are drawn from the point where the descend path cuts the MDA to the missed approach point? See Calais and Le Mans chart compared to the Bergerac chart.

2. Does anyone know the specifics for a FAF so for a point to be drawn as a Maltese cross? See chart Bergerac. it’s not a DME fix or a station but simply a GPS fix.

Thanks




The NDB is either,
1) MAPt marker for starting the missed approach at MDH (MAP)
2) Mandatory Altitude marker before descending to MDH on DnD (or FAP if you are in CFDA)

In 2), the NDB will be behind you, that makes a fun final segment to get a magic formula (RBI, RYW, HDG, Wind) to stay on track for threshold, having the tail pointing at 180 after passing NDB overhead is not good enough also, it’s “timed NDB”, missed point MAPt marker comes from your stopwatch clock !

The time “NDB to MAP” is listed on the plate vs your ground speed

PS: you will need ADF to fly these but DGAC accepts (even recommends) flying them on GPS overlays while monitoring ADF tune music & max 10deg deviation for go-around (sort of RAIM+LOI for the NDB/GPS), also it’s less fetish to fly “raw NDB IAP & Hold” in the training environment, everything is done on GPS (except one ATO in France flies Guépard Wassmer for SEIR training & PA34 for MEIR, their training manuals are like the ones you would get in Bournemouth or Stapleford )

Last Edited by Ibra at 29 Apr 10:32
Paris/Essex, United Kingdom

1) You may find the answer in this Jeppesen bulletin:

Jeppesen_Bulletin_JEP_15A_Aerodrome_Operating_Minimums_Web_Version_pdf

For NPAs where the use of VDA or VNAV guidance is required, or the NPA is designed as a continuous
descent, the flight path will be depicted as a continuous path from the FAF to the MAP
using a thick line. For vertically guided NPAs this will become the primary depiction method.
(+ For U.S. NPAs only, a DA profile note will be added where applicable as described below.)

For NPAs where VDA or VNAV exist but its use may be optional (the NPA may be flown With or
Without VDA or VNAV), a combined depiction will be made. The flight path With VDA or VNAV will
be depicted as a continuous path from the FAF to MAP using a thick line. Additionally, to accommodate
the alternative or conventional method of descent Without VDA or VNAV, a secondary
flight path will also be depicted using the conventional Level Segment depiction method using a
thin line. (+ For U.S. NPAs only, a DA profile note will be added where applicable as described
below.)

2) According to the Jeppesen Glossary, the Maltese cross symbol is:

So it may be the French authority didn’t specify the FAF.


United Kingdom

Thanks Ibra. The fact that the MAP is found via timing, resulting in no dashed lines makes sense!

But why would they mention non-CDFA minima if the ROD and the starting point of your descend (NDB) is the same? I.o.w the point at which you will reach MDA/DA will be more or less the same as well. According to a 3° angle this will be the position of the old school VDP as well. See charts Calais and Le Mans approach compared to Bergerac.

Alpha_Floor: Do I understand it properly when I say in case there are no dashed lines drawn and the descend point is indicated with a GPS wpt identifier only+ CDFA minima only, this means you can only fly the approach with a VNAV system?

TDJ737 wrote:

But why would they mention non-CDFA minima if the ROD and the starting point of your descend (NDB) is the same?

To fly a NPA using the CDFA technique one needs some form of range source: either DME or GPS.
So if you don’t have either, you use the non-CDFA (old dive and drive), descend to the MDA, and then go around at the MAP which is found via timing from the FAF. You can descend at a 3º angle to your MDA if you like, but you won’t be able to assess your descend path because you’ll have no distance information.

TDJ737 wrote:

Alpha_Floor: Do I understand it properly when I say in case there are no dashed lines drawn and the descend point is indicated with a GPS wpt identifier only+ CDFA minima only, this means you can only fly the approach with a VNAV system?

I don’t think so, you can still fly the approach using the distance vs altitude table. Otherwise CDFA in most light GA with conventional instruments wouldn’t be possible.

Give that Jeppesen Bulletin a read, it’s quite interesting!

Last Edited by Alpha_Floor at 29 Apr 11:09
United Kingdom

Here’s another example of an NDB approach that can be flown CDFA or non-CDFA depending on whether you have a GPS distance to RW07. This is in practice achieved with an approach overlay.

The funny thing here is that no timing is provided to find the MAP, which is the NDB. So you would fly this pretty “blindly” if all you had was an ADF. Watching that needle very closely and going around once it swings around 180º before you hit El Teide :)
I wouldn’t want to fly such an approach in IMC without a GPS overlay.

United Kingdom

Just out of curiosity: Has anyone in this group ever practiced flying NDB approaches with the NDB in the back? If so: Did you do your instrument ticket before or after the war?

I admit I’ve never done that – not even in the sim – and I would not fly such an approach if I’m not clearly visual at the fix.

Last Edited by Malibuflyer at 29 Apr 11:25
Germany

TDJ737 wrote:

But why would they mention non-CDFA minima if the ROD and the starting point of your descend (NDB) is the same?

If you take Bergerac,
- CFDA: you calculate RoD and start continuous descent from FAF = FF27 (decided by clock time) but you need to cross NDB at 1440ft
- DnD: you descend as you wish after FF27 but you have to pass above NDB at 1440ft before descent as you wish to MDH

Here is what happens when one flies NDB with a watch and confusing where the NDB sits vs ARP/MAPT/THR !
A bit of situational awareness would have helped GPS (was not authorized) & DME (was U/S) but they still have ForeFlight & SkyDemon

here

GPS/DME/ADF mix or cheat are not good neither: one risk having WTF moments on OBS, Holds & Direct-to modes in France, it has a heavy use of non-collocated DME/NDB fixes with double points in GNSS database, although a glance to your favorite moving map ForeFlight & SkyDemon & JeppFD should save the day

Here is the list of places I know where one should not do any cuisine on GPS or ADF
- RL NDB, RL DME at La Rochelle
- MP NDB, MP DME at Cherbourg
- MT NDB, MT DME at StNazaire
The followings have disappeared after ILS/DME or NDB was removed: MK at Calais, LM at LeMans and LT at LeTouquet

Malibuflyer wrote:

Just out of curiosity: Has anyone in this group ever practiced flying NDB approaches with the NDB in the back? If so: Did you do your instrument ticket before or after the war?

Haha, I did load of NDB during IMC & CBIR training in UK but none was in the back, it’s what the whole CAA IR thing is about, and also did Lydd NDB once for real (funny that ILS DH > NDB MDH), but over there one can be visual over water at 500ft in Class G, ahem without even asking ATC for an IAP

There are few NDB in the back in Latin America, easy stuff to practice in a simulator while sitting in cozy couch…

[ URL made into a clickable link ]

Last Edited by Ibra at 29 Apr 11:42
Paris/Essex, United Kingdom

Malibuflyer wrote:

Just out of curiosity: Has anyone in this group ever practiced flying NDB approaches with the NDB in the back? If so: Did you do your instrument ticket before or after the war?

Oh, yes! Which war? :-)

ESKC (Uppsala/Sundbro), Sweden

Malibuflyer wrote:

Just out of curiosity: Has anyone in this group ever practiced flying NDB approaches with the NDB in the back? If so: Did you do your instrument ticket before or after the war?

Yes, and very recently as a legitimate approach, not requested for training: EGTK Oxford NDB 01, on the way back from EDDW.
But in VMC and with the GPS overlay, with the HSI in GPS mode giving me a LOC-like final approach track.

“Pure” NDB, with only an ADF: only in the sim (X-Plane 11).

I also practiced a single engine, no gyros, no compass ILS in an FNPT-II, in IMC to minima. Not in the training syllabus but loads of fun.
Not so much fun if you were forced to do it for real :)

Last Edited by Alpha_Floor at 29 Apr 12:00
United Kingdom
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