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VOR checks in Europe - how?

Yesterday, I have flown the VOR 27 approach at EDDR for practice:

For the fun of it, I have flown it primarily on raw VOR data, i.e. referencing primarily the VOR radial (which I displayed on the PFD) and not the approach overlay shown on the GPS screen.

It’s an interesting approach, as the VOR is off the field, by a whopping 11.6 miles.
I flew the radial quite accurately, but when I was approaching the MAP and looked up, I found
that I was pointed quite a bit south of the airport. (If you look closely: the chart actually does show that the 265 radial will not direct you straight towards the runway, and I think that’s te reason why the put the MAP 0.8 NM from the threshold, but during my approach briefing, I hadn’t noticed this. In my opinion, it could be made a little more clear on these charts, to make people aware they have to look a bit to the right at minimums).

Lessons learned:
-these VOR approaches really are non-precision approaches!
-if the weather is bad, do expect you will not find the airport
-always prefer the GPS approach over the VOR approach

EDIT: Just found the note about the offset on the chart!!

However, it also got me thinking about VOR accuracy. I am too lazy to the maths right now, but even if the VOR was de-tuned by only 1 degree, that one degree would have been sufficient to fly me totally past the airport, with no chance to see it.

So, if you do it, how do you do a VOR check in Europe, both from legal and practical points of view?

For reference, here is FAR 91.171.

So, with practically no VOTs here, and no designated VOR checkpoints and no VFR charts showing airway centrelines? One can do the “check one VOR against the other thing” but it hardly gives any reassurance because both might be off. Also, some aircraft only have one VOR receiver in the aircraft.
For practical purposes, I think it’s best to check it against a GPS bearing indication.

Last Edited by boscomantico at 20 Feb 21:08
Mainz (EDFZ) & Egelsbach (EDFE), Germany

By the way, the AIP plate does not grapically depict the “offset” at all, but it does have the textual note:

Last Edited by boscomantico at 20 Feb 21:10
Mainz (EDFZ) & Egelsbach (EDFE), Germany

AFAICT you can only do the dual VOR check, i.e. check one NAV receiver against the other. The two bearings need to be within 4° of one another. Another possibility is to have it done at an avionics shop that can output an appropriate signal.

On the N-reg airplanes I have flown in Europe so far, I’ve been lucky enough for them to have 0° difference.

LFPT, LFPN

If you have two VORs, I would use those in Europe. If not, this:

(ii) Select a prominent ground point along the selected radial preferably more than 20 nautical miles from the VOR ground facility and maneuver the aircraft directly over the point at a reasonably low altitude; and

(iii) Note the VOR bearing indicated by the receiver when over the ground point (the maximum permissible variation between the published radial and the indicated bearing is 6 degrees).

Finding the “ground point” with your GPS isn’t forbidden either…

Those airborne tests never had any appeal to me. But of course at least you can say that you have complied.

LFPT, LFPN

FWIW – the FAA VOR check was – legally – checking the difference between the two receivers, and – practically – checking both against the GPS bearing. I noted all three down on the little sheet to prove it has been done to satisfy the ramp checkers.

About that approach: 1-in-60 rule is your friend. the MAPT is around 10 NM from the VOR, so 1 degree is 1/6th of a mile, and being two degrees out makes it 1/3 of a mile off.

if, at around 1 mile from the runway you are 1/3 of a mile off, you need to look almost 20 degrees to the side, compared to that, the 1 degree offset of the radial is negligible. Even a 0.5 degree total error is around 5 degrees angle to the runway at that distance.

Last Edited by Cobalt at 20 Feb 21:45
Biggin Hill

There must be VOT’s in Europe that you can check against, no?

Last Edited by AdamFrisch at 20 Feb 22:37

I check one VOR against the other.

EGTK Oxford

Adam, no, but that’s because, under European aircraft registrations, VOR checks by pilots don’t exist / aren’t required.that’s why we have those yearly (or whatever) avionics checks done by avionis guys, costing between 500 and 1000 Euros..

The “problem” therefore really only exists for pilots of N-regs that are based in Europe.

I seem to remember having seen one (a VOT) on an aerodrome chart somewhere once, maybe in the Netherlands, but might have been somewhere else.

Last Edited by boscomantico at 20 Feb 22:46
Mainz (EDFZ) & Egelsbach (EDFE), Germany

We did this here before some time ago… I think there is no legal way to do the FAA VOR check in Europe (or probably anywhere outside the USA) unless you have two receivers and check one against the other.

Obviously the right way to do it is to set up a GPS DCT to a VOR, fly in in NAV an autopilot, and check your VOR receiver(s) that way. That is super accurate but it doesn’t meet the FAA requirements…

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Shoreham EGKA, United Kingdom
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