Westcott NDB?
(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
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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.
** 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.
Last edited by Jan Olieslagers; 5th May 2024 at 13:25.
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
G
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!
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!
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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).
Last edited by Jan Olieslagers; 6th May 2024 at 12:33.
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!
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!
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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.)
The 'County Sound' Tx at Guildford was used for this but I think it switched to FM.
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
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
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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.
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.
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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.
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.
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.
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.
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.
Last edited by Big Pistons Forever; 9th May 2024 at 00:07.
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Going back to the original thread...
EGLL notam issued for the WCO NDB
Few weeks to go, but seemingly it'll be back.
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.
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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.
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Unjammable navigation tech gets first airborne test https://www.bbc.com/news/articles/cz744gpl1dpo
