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GPS substitution for navaids - allowed?

What is the likelihood of us Europeans getting a formal concession for this?

Much as we all hate NDB holds in the initial Euro IR test, etc, there is no getting away from it for the IRT - as long as NDBs remain, and they remain in huge numbers all over Europe.

Unless Europe gets a formal US-style GPS substitution for NDB/DME/VOR (which already exists to some degree in airline ops, with FMS (i.e. GPS- or INS-based RNAV) procedures) it has to be this way.

I am too lazy to go looking for this but has anybody seen the Swiss AIP lately? The equipment list for each country is supposedly in the country's AIP GEN 1.5. I researched this completely intractable matrix of equipment carriage versus airspace a bit in 2005 and found that for Switzerland it returned the interesting result that a BRNAV GPS removes the need for an ADF for all IFR flight (ADF is still explicitly required for approaches containing NDBs, as one might expect). Switzerland is non-EU even now.

The only sure way to avoid NDB stuff for the JAA IR is to do it where it isn't tested. FIS at Jerez was one place; I don't know if they still work like they used to since their chief instructor (a Brit) had a post ferry flight swim off Hawaii. I emailed them recently but they avoided replying to specifics. The better known FTE at Jerez uses UK examiners and is therefore no good for this purpose; they do the full torture process. Egnatia in Greece also didn't do much (if any) NDB stuff when I visited them in 2009 and 2011.

However, when I did the FAA IR in the USA in 2006, I was told that if an ADF had been installed (it wasn't) the examiner was entitled to see it used. I don't know whether this meant that the substitution could be set aside for the IR test, or whether it was because the plane was not equipped (it had some old GPS but nothing fancy like a GNS430 etc).

Shoreham EGKA, United Kingdom

Most (all?) EU countries do not mandate an ADF unless you perform an NDB approach. If you perform those approaches, you have to have an ADF on board but nobody in his right mind would actually use it for the approach. As to actually having it, I've never heard about any authority enforcing this.

It's like with DMEs. You need to have them for every procedure requiring a DME (and many if not most ILSes do) and some countries even require DMEs for IFR in their airspace (Germany) but it is not being enforced and violated every day.

So keep your half-dead ADF in the cockpit but don't use it for anything but listening to radio stations.

So keep your half-dead ADF in the cockpit but don't use it for anything but listening to radio stations.

We (in Croatia) have to demonstrate ADF usage at yearly IR check performing NDB approaches and holdings.

LDZA LDVA, Croatia

Blue sky thinking would suggest that today the technology exists to render even my no electrics/no gyro SC IFR - a helmet with self contained GPS and ADHRS, plus COM/ADS-B and HUD.

Enstone (EGTN), Oxford (EGTK)

We (in Croatia) have to demonstrate ADF usage at yearly IR check performing NDB approaches and holdings.

I had to fly an NDB approach during my initial IR exam. Just when I tuned the ADF (and started to sweat), the examiner asked "are you nuts? Do you want to kill us? Why do you even turn this thing on when you have a GNS430 on board?".

This was the last time I tried to use the ADF for anything even though the one in my TR182 works reasonably well. For the yearly check ride, there is no NDB anywhere near my airfield, only RNAV/LPV, VOR/ILS so the topic would never come up but no instructor would make me use this POS (piece of s***) device other than to satisfy the equipment list.

ADFs are like those mechanical "flight computers". New pilots think they are actually important until they become more experienced and realize they are both useless.

Some of you will remember epic NDBs like Kitzingen, Giessen or Lichtenau...they have been decomissioned not all too long ago. But yes, nobody really actually used them in the last 15 years. I remember them mainly from my MSFS days...

In certain countries, NDBs are still very much en vogue. Georgia (not Georgia USA, but Georgia in the Caucasus region...a beautiful country BTW) has enormous numbers of fairly strong NDBs to define their airways and also for approaches.

Mainz (EDFZ), Germany

France permits GPS substitution for NDBs and DMEs

Here and here

The first one dates back to 2007! Clearly not many people know about it.

The requirements are not trivial and the operator needs to apply for the permission, if I read it correctly.

I suppose this is what AOC operators have had for many years, all over Europe, but they do normally have to carry an ADF and for example verify the NDB is working.

The second one is more general but still hard to work out the exact limitations.

The French AIC list is full of this kind of stuff … for those with time Here is a marvellous one on the use of GPS for VFR, with this stunning statement:

Last Edited by Peter at 05 Apr 20:08
Shoreham EGKA, United Kingdom

France is more restrictive than the US. AC 90-108 lists the US rules for substitution. The only segment of a NDB approach that must use the VOR or NDB when it provides the lateral guidance is on the final approach segment. The initial, intermediate, and missed approach segments have no restrictions. On a localizer course, GPS may be used but the raw localizer indication on a CDI display must be presented on any localizer based course and the final approach lateral guidance is based solely on the localizer.

a. Usage of Suitable RNAV Systems. Subject to the operating requirements in this AC, operators may use a suitable RNAV system in the following ways.
(1) Determine aircraft position relative to or distance from a VOR (see first note in subparagraph 7b), TACAN, NDB, compass locator (see second note in subparagraph 7b), DME fix; or a named fix defined by a VOR radial, TACAN course, NDB bearing, or compass locator bearing intersecting a VOR or Localizer (LOC) course.
(2) Navigate to or from a VOR, TACAN, NDB, or compass locator.
(3) Hold over a VOR, TACAN, NDB, compass locator, or DME fix.
(4) Fly an arc based upon DME.
b. Specific Allowances. The allowances described in this section apply even when a facility is identified as required on a procedure (for example, “Note ADF required”).
NOTE: For the purpose of this AC, “VOR” includes VOR, VOR/DME, and VORTAC facilities.
NOTE: For the purpose of this AC, compass locator includes locator outer marker and locator middle marker.

8. USES OF SUITABLE RNAV SYSTEMS NOT ALLOWED BY THIS AC. An otherwise suitable RNAV system cannot be used for the following:
a. NOTAMed Procedures. Unless otherwise specified, navigation on procedures that are identified as not authorized (“NA”) without exception by a NOTAM. For example, an operator may not use a RNAV system to navigate on a procedure affected by an expired or unsatisfactory flight inspection, or a procedure that is based upon a recently decommissioned NAVAID.
b. Substitution on a Final Approach Segment. Substitution for the NAVAID (for example, a VOR or NDB) providing lateral guidance for the final approach segment.
c. Lateral Navigation on LOC-Based Courses. Lateral navigation on LOC-based courses (including LOC back-course guidance) without reference to raw LOC data.
KUZA, United States

I just was browsing future destinations at

Looked at EDHL, NDB (GPS) RWY 25.

Haven’t flown so much IFR outside Sweden, but if it was on a FAA chart i would have thought GPS substitution was allowed here?

Last Edited by Jonas at 16 Jun 12:16
ESOW Västerås, Sweden

While we’re talking NDB’s and ADF: did I hear the socialist countries iow the Moscow hemisphere had a standard layout of TWO NDB’s for each runway, corresponding more or less to the outer and middle markers? And that there even was a kind of standard procedure that used both for a (more or less) precision approach?

EBZH Kiewit, Belgium
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