Westcott NDB?

[Level Attitude]

Wanting to practice some ADF tracking, on both 20th and 26th April I tuned to WCO (335 kHz).
On both dates no ID could be heard and no signal detected (ADF needle didn't move).

As far as I could see, there were no relevant Notams concerning WCO.
Does anyone have any suggestions as to why WCO was not working?

NB: Aircraft ADF was definitely working as could ID and track both HEN and CHT.

[Jan Olieslagers]

I think you were lucky to find CHT still active: it is no longer mentioned in the AIP, just like WCO. HEN still is, but perhaps not for very long. There is a general tendency to phase out NDB's, as I understand.

Check it out at https://nats-uk.ead-it.com/cms-nats/opencms/en/Publications/AIP/Current-AIRAC/html/index-en-GB.html , section ENR 4.1

[340drvr]

Back in the day, we used to use a local AM radio station for NDB tracking practice. Even had a homemade "ADF approach plate" drawn up for use in instrument training. (No need to comment, it was all just for practice only, never intended for real IFR usage, way too close to mountains and other obstacles, it would have had to have 2500 feet AGL minimums or worse.)

[Jan Olieslagers]

But AM / medium wave broadcast stations are being phased out, in Europe at least, just like NDBs.

[BoeingBoy]

I thought WCO had gone years ago. It's no longer listed in the AIP although SkyDemon still shows it.

The only enroute NDB in the UK listed is Woodley.


UK AIP enroute navaids (https://www.aurora.nats.co.uk/htmlAIP/Publications/2024-04-18-AIRAC/html/index-en-GB.html)
Click on ENR 4.1

[spekesoftly]

The only enroute NDB in the UK listed is Woodley.

Henton NDB is another.

[chevvron]

In the '60s, there was an NDB at Brill used by Martin Baker.

[Genghis the Engineer]

Wanting to practice some ADF tracking, on both 20th and 26th April I tuned to WCO (335 kHz).
On both dates no ID could be heard and no signal detected (ADF needle didn't move).

As far as I could see, there were no relevant Notams concerning WCO.
Does anyone have any suggestions as to why WCO was not working?

NB: Aircraft ADF was definitely working as could ID and track both HEN and CHT.

I was doing practice approaches Wednesday on 03 at Cranfield. I couldn't ident or track WCO either, but could get CIT. I reported it on RT to Cranfield Approach, who thought it should have been serviceable.

Report these things, or nothing'll get done.

G

[eglnyt]

In the '60s, there was an NDB at Brill used by Martin Baker.
NATS is busy switching off the NDBs as fast as the CAA will let it. As en-route procedures using the NDB are removed/RNAV'd the entry for that beacon is taken out of the en-route section of the AIP. Several of them are still included in airport procedures in which case they have been moved from the en-route listing to the listing for the relevant airport(s). That of course makes it next to impossible to find out whether or not an NDB is still in service without searching through the entry for any airport that might be nearby. The same will increasingly start to apply for VORs.

WCO was a part of Cranfield procedures, if it's gone from their AIP entry it's probably switched off. CHT and HEN still feature in some airport procedures which is why they are still switched on. For some reason they followed a different approach for WOD and marked the en-route entry to say it has no en-route dependency even though they also put it in Heathrow's part of the AIP.

[eglnyt]

When WCO was removed from the En-Route section of the AIP it was moved to EGLL AD 2.19 and it's still there in the current AIP so should still be in service and notamed if it isn't radiating. It isn't in Cranfield's equivalent section despite appearing on their chart.

[Genghis the Engineer]

Just double checking NOTAMs and the UK AIP, the NDB/NDB/DME approach to 03 at EGTC that uses WCO is still published, and the only NOTAM at that location is of BVLOS drones to 800ft. So it should work, notwithstanding recent experiences !

G

[MrAverage]

Many, many operators from nearby airfields use(d) WCO to teach basic ADF skills, as well as simulating NDB approaches if chosen carefully. Thus saving students the cost of getting to approaches further afield, not to mention the frequent problem of being unable to book those approaches. If it's withdrawn it will be even harder to book elsewhere.................

[chevvron]

Many, many operators from nearby airfields use(d) WCO to teach basic ADF skills, as well as simulating NDB approaches if chosen carefully. Thus saving students the cost of getting to approaches further afield, not to mention the frequent problem of being unable to book those approaches. If it's withdrawn it will be even harder to book elsewhere.................
Yes when we started operations on the 'North' sector of Farnborough LARS in 2008, it was immediately apparent how 'popular' WCO was with traffic out of Oxford, Denham and Wycombe, both with traffic seen on radar and many of them calling us up so we could supply generic information to people operating there.

[eglnyt]

Yes when we started operations on the 'North' sector of Farnborough LARS in 2008, it was immediately apparent how 'popular' WCO was with traffic out of Oxford, Denham and Wycombe, both with traffic seen on radar and many of them calling us up so we could supply generic information to people operating there.
When NATS consulted on VOR rationalisation there were some that GA wanted to keep including DTY & TRN. None made it to the list. Whoever thought HON and TLA were suitable alternatives had no understanding of the surrounding airspace or the ground below. There wasn't as far as I know any consultation on NDBs with an assumption that people wanted rid of them as soon as possible.

[Genghis the Engineer]

What's the expression I remember from RAF training. "Never check, assume".

Or something like that.

G

[Jan Olieslagers]

NDB's are a thing of the past, as we read here. Why should anyone wish to practice the associated procedures? Or they should still be required in the various skills tests, of course.

[BoeingBoy]

Plenty of airfields in the UK still have local NDBs in use with holds and procedures based on them. Whilst they are all but gone in most countries that have modernised to RNP approaches, I'm afraid that here in dear old Blighty we'll be training for the hold well after I hang my headset up.

[Fl1ingfrog]

The NDB is relatively cheap to install and maintain so practical for small airfields to retain. Once the artificially high demands for approved GPS approaches become affordable then they will have little use other than for a few.

[ShyTorque]

NDBs are useful GPS waypoints….. ;)

[Equivocal]

NB: Aircraft ADF was definitely working as could ID and track both HEN and CHT.Last time I drove past where CHT is/was - a couple of months ago - I noticed that the mast/antenna appeared to have gone.

[Genghis the Engineer]

NDB's are a thing of the past, as we read here. Why should anyone wish to practice the associated procedures? Or they should still be required in the various skills tests, of course.
(1) They require little and cheap infrastructure
(2) They are, unlike GPS, relatively immune to jamming and interference
(3) If you can successfully fly NDB holds and procedures, the skills thus learned map really well to flying anything more modern. Thus they are a very useful training aid.

The main argument against learning to fly NDB procedures is the scarcity now of certified and serviceable ADFs.

Without doubt ILS or VOR with/without DME procedures are far easier to fly, and more accurate to fly. The bad news is authorities hellbent on retiring the ground infrastructure for those, because of the cost. In a somewhat negative way, that is also a strong argument for maintaining the skills associated with NDB holds and procedures.

G

[Jan Olieslagers]

Will all due respect, @GtE, I am finding your point 3) weak** and 2) incorrect. Myself an humble electronics amateur, I could create an NDB jammer at short delay, and at a very modest cost. OTOH I wouldn't even know how to begin a GNSS jammer - this will always be more complex and more expensive. If NDB's are little jammed, it is perhaps because nobody cares to try, or perhaps it is actually done without being observed, NDB/ADF being considered little reliable anyway; so that possible perturbations are not automatically associated with intentional sabotage.

** if the goal is to learn and drive a car, is it beneficial to first learn a push-bike? Yes, sure. Is it worthwhile? Hmm.

[Genghis the Engineer]

You don't need to build a GPS jammer, you can buy one online a few tens of pounds. Various reasons people might want to jam GPS signals, some probably rather dodgy, but the fact is - they can: little money and absolutely no skill needed.

G

[BEagle]

My car Garmin has been jammed a few times - probably by dodgy truck drivers trying to defeat telematics. Twice at M25 J26 the jamming froze my SatNav so that I couldn't even turn it off, blocked my cellphone and even blacked out my FM radio. I suspect that the jamming came from the truck park at the 'J26 Diner'!

I even had to wait until the SatNav battery ran down before I could restart it..... So now I turn my SatNav off in that neck of the woods!

[Jan Olieslagers]

You don't need to build a GPS jammer, you can buy one online a few tens of pounds. Various reasons people might want to jam GPS signals, some probably rather dodgy, but the fact is - they can: little money and absolutely no skill needed.

G
I do not doubt it, but that is not my point. My point is that NDBs are even easier to jam/disturb than GNSS. Invalidating your point (2).

[chevvron]

My car Garmin has been jammed a few times - probably by dodgy truck drivers trying to defeat telematics. Twice at M25 J26 the jamming froze my SatNav so that I couldn't even turn it off, blocked my cellphone and even blacked out my FM radio. I suspect that the jamming came from the truck park at the 'J26 Diner'!

I even had to wait until the SatNav battery ran down before I could restart it..... So now I turn my SatNav off in that neck of the woods!
Could this be done using the DGPS signal which is 'piggybacked' on the signals from local FM broadcast stations.

[eglnyt]

I do not doubt it, but that is not my point. My point is that NDBs are even easier to jam/disturb than GNSS. Invalidating your point (2).
It's quite a complicated thing to decide which is harder. Years ago generating a signal suitable for jamming GPS would have been difficult whereas the frequency for jamming NDBs would be much easier. However the advancement in semi conductor devices means that is no longer the case. Which is easier to jam is dependent upon how big an area you want to jam and whether you want to jam all NDBs or just one. One NDB over a small area would be quite easy but would still require more power and bigger physical kit than local jamming of GPS. For a single NDB you can probably scale up the area jammed easier than you can for GPS but jamming all NDBs in an area is probably harder. And if you factor in convenience, I can buy a GPS jammer on-line and use it out of the box with no technical knowledge other than some poorly written instructions but would probably have to use specific technical knowledge and non-specific technical kit to jam NDBs, I'd argue that GPS is easier.

[Fright Level]

Back in the day, we used to use a local AM radio station for NDB tracking practice. Even had a homemade "ADF approach plate" drawn up for use in instrument training. (No need to comment, it was all just for practice only, never intended for real IFR usage, way too close to mountains and other obstacles, it would have had to have 2500 feet AGL minimums or worse.)

I believe Capital Radio has been informally used for the approach to Elstree on more than one occasion. They were on 194 metres (1548KHz) and Kenny Everett's voice was sufficient to have ID'd the beacon!

[chevvron]

I believe Capital Radio has been informally used for the approach to Elstree on more than one occasion. They were on 194 metres (1548KHz) and Kenny Everett's voice was sufficient to have ID'd the beacon!
The 'County Sound' Tx at Guildford was used for this but I think it switched to FM.

[Genghis the Engineer]

My point is that we shouldn't be reliant upon a single technology, that can be interfered with in a single way.

GPS is amazing technology, it is obvious why most of us use it as our primary navigation source. And to do so is fine.

Where I have big issues is with the steady withdrawal of all other options. Yes, NDBs are poorer, old, harder to use technology. But, critically, they work - and any actions to interfere with GNSS should have no impact upon them, and vice-versa.

G

[Jan Olieslagers]

Thanks GtE, I can quite go along with that. Actually I realised that, where I stated that NDBs are easier to jam than GNSS, that was seeing from an electronics point of view only.
And indeed we should not rely on one single technology, especially one that is so prone to disturbances. I understand the official answer to that is the creation of a network of DME stations, from which the position can be determined by triangulation, but I think few light planes will carry the required equipment.

[eglnyt]

Thanks GtE, I can quite go along with that. Actually I realised that, where I stated that NDBs are easier to jam than GNSS, that was seeing from an electronics point of view only.
And indeed we should not rely on one single technology, especially one that is so prone to disturbances. I understand the official answer to that is the creation of a network of DME stations, from which the position can be determined by triangulation, but I think few light planes will carry the required equipment.
The beacons currently being withdrawn by NATS are en-route/area facilities. The backup solution for that provision in the absence of GPS is a network of VOR/DME stations which have recently been updated. Obviously that is only of use if you have the right equipment in the aircraft. Longer term the VOR element will be withdrawn leaving just DME with DME/DME being the fallback, again with the need to have a suitably equipped aircraft. In most of the UK there are already sufficient DMEs for that but there are too many DMEs in the South East, not enough in some other areas and a number that can't stay where they are because of safeguarding issues. As far as I am aware there has been no consultation on what the future DME network should be although the recent introduction of 3 new DME only installations would suggest somebody has some idea. Provided there is sufficient coverage the actual locations shouldn't really concern users.

Any fallback provision for aerodrome procedures is a matter for each procedure owner. If current en-route beacons aren't part of the retained VOR/DME network but are used in aerodrome procedures NATS has been clear it would expect the aerodrome to pay the cost of retaining that facility for those procedures. As a result most are intending to replace those conventional procedures with GNSS RNAV as soon as possible. Whether there has been any consideration of a fallback for GP failure in those case I don't know.

[Big Pistons Forever]

I can think of numerous instances where my ADF was “jammed” by a thunderstorm or “spoofed” by shoreline effect.

Personally I think training is better by looking forward rather than backwards. Rather than learning the mechanics of NDB homing and tracking I think more training time should go into mastering big picture Nav skills.

- Is where the magic taking you where you want to go, or some other random place due to a data entry error?
- what data do you want on the screen and why?
- What map scale should you be on for this phase of flight?
- Is the route you entered the best route given, weather, wind, terrain, water, efficiency?
- How accurate is the Nav (ie understanding DOP)
- what is the plan if the unit suddenly goes to DR mode
- what is the plan if the screen goes blank.

[Cough]

Going back to the original thread...

EGLL notam issued for the WCO NDB

A3164/24 NOTAMN Q) EGTT/QNBAS/IV/BO /A /000/999/5151N00058W005 A) EGLL B) 2405041545 C) 2406041800 E) NDB WCO/WESTCOTT 335KHZ U/S

Few weeks to go, but seemingly it'll be back.

[eglnyt]

Going back to the original thread...

EGLL notam issued for the WCO NDB



Few weeks to go, but seemingly it'll be back.

That's an interesting development. It probably wasn't working on 20th April but the NOTAM wasn't issued until 4th May. That equipment should phone home when it failed and probably once every 24 hours even if all is ok just to check that the monitoring is functioning correctly. If it couldn't be remotely reset then a NOTAM should have been raised at the time it failed. Even after users complained it wasn't working it seems to have taken a few days to raise the NOTAM. That may be because it will phone home to Swanwick and it now seems to be a Heathrow responsibility to raise the NOTAM. It will be interesting to see whether the NOTAM is just the longest expiry date/time they could raise and other NOTAMs will follow or they actually intend to put it back in service.

[Bug]

Re backup for GPS in national airspace.
Article in Flight re Estonia bolstering ground aids due GPS unreliability.

https://www.flightglobal.com/air-transport/finnair-to-restore-tartu-service-after-gps-alternative-implemented-in-estonian-airspace/158324.article

[sixgee]

Unjammable navigation tech gets first airborne test https://www.bbc.com/news/articles/cz744gpl1dpo

[eglnyt]

Going back to the original thread...

EGLL notam issued for the WCO NDB



Few weeks to go, but seemingly it'll be back.
NOTAM now extended until September 2024