LeSving wrote:
Dependence on super sensitive systems that any person can jam isn’t exactly forward looking.
Fair enough, but maybe it would be better to keep an old VOR than install several new NDBs?
Airborne_Again wrote:
Fair enough, but maybe it would be better to keep an old VOR than install several new NDBs?
Too expensive…
I read somewhere that few years ago the cost of NDB install is around EUR60K, ILS – around EUR2M per threshold, VOR – EUR500K.
How does it look like these days I don’t know. And I don’t know how much it costs to install Terminal VOR.
A friend of mine mentioned to me someone he knows through the RSGB who maintains the current NDBs. Everything about them is obsolete. When one goes down he travels out to it with a van full of spare boards, replaces the failed one, then takes it home and fixes it with his collection of germanium transistors, carbon resistors, paper capacitors and so on, ready to reuse the next time.
Of course you COULD knock up an NDB in half an hour with modern components, but then it wouldn’t have been through the CAA/EASA approval process which would take another 5 years and add at least three zeroes to the manufacturing cost.
Even if NDBs are installed as an emergency system, how many aircraft would be able to receive it? No GA plane built in the last 20 years has an NDB receiver – this has been done to death on other threads. Someone said that they are an option for current airliners, but how many have them? Once again you’d end up paying millions per aircraft to install something that would never be used. If GPS really became unavailable, you’d be a lot better off letting down over water (or the Netherlands) then pootling about at 1000 feet to find somewhere to land.
AFAIK that is correct. There is a man who drives around in a van full of spare boards and swaps them around.
However I suspect that is the cheap option, which all the smaller airports go for. I am sure that somebody has designed modern kit. For example a long time ago I spoke to someone who used to work at Philips who maintained the VOR network in the 1970s. They don’t do it now, but clearly somebody does. There is a lot of money in it. It is like runway lights; a lot of money in that business, and the companies travel all over the place. Same with flight calibration.
Thales manufacture (or recently did) very modern ILS systems.
I am not sure whether FAA or EASA get involved directly. This is not an aircraft Major or Minor mod. There will be ICAO specs for the emissions, and you develop the kit and have to take it to a $1k/day lab to test it and you get a certificate. It’s like the European CE EN emissions/immunity regs; a lot of it is a charade which has basically done nothing for anybody but keeps a lot of hangers-on working in the labs being able to drive huge BMWs and pay for their kids’ schooling 
NDBs are all over Europe. Even if nobody ever uses them for navigation, they are a cheap way to facilitate commercial traffic.
My local aeroclub has recently refurbished their NDB. One of its members completely rebuilt it using modern electronics got it all approved through the CAA. He did this all for free and although I don’t know what the CAA charges were I don’t think it was much.
There was a fair bit if paperwork as NDB’s are regarded as national navigational infrastructure. So an an SMS had to be drawn up as did a maintenance contract – the geek set himself up as this.
Unfortunately this is the UK and not the USA virtually every aircraft I fly has an ADF fitted and frankly they have to. It’s by far the most common approach available and at many airports it’s the only option.
ENBL Førde has had GBAS/GLS approach for some years now. I guess other Norwegian airports also?
But like DME/DME, GBAS is no help for GA in case of GPS outage. eLORAN would be an ideal low cost backup for GPS as it has very good coverage, is practically unjammable and I guess it would be straightforward to include the receiver in a GPS navigator – but there is no real drive for that yet.
VORs are being decommissioned here in Denmark as everywhere else, but the flight school industry and AOPA have had some success in pressuring the airspace authority to leave some of the VORs a few years more, so EKRK, the country’s GA center, actually still has 3 VOR/DMEs within 25 NM and 2 of them should last for years to come, maybe until 2030.
What happened to TLS – Transponder Landing System? I think it was actually CAT I certified in the US back in the late 90’es. The beauty of the system was that it required no installation in the aircraft apart from a mode A transponder and a conventional ILS receiver/indicator. Also, like the MLS, it works well in terrain where ILS wouldn’t work, and it can provide curved or steep approaches if required. The downside is that it can only guide one aircraft at a time, and of course requires specific ground equipment. But it just seems it would be a logical extension to the radar-vectoring that seems to be the only future GA-backup during loss of GPS.
arj1 wrote:
Too expensive…
Sure, but still a step backwards.
What would be a step forward?
huv wrote:
ENBL Førde has had GBAS/GLS approach for some years now. I guess other Norwegian airports also?
Aren’t the Norwegian GLSs early trial installations only used by Widerøe? The LPV at ENBL has as good minima as the GLS.
Peter wrote:
What would be a step forward?
I don’t know, but keeping the relevant VORs would at least be standing in the same place.
