Originally Posted by
Jan Olieslagers
Excuse me for not having a real answer. Only in the margin:
On the general trend, NDB's are a thing of the past. In Europe at least, and probably elsewhere too, they are being phased out quite rapidly.
The UK is of course a somewhat peculiar place - by which I mean nothing negative! - but sooner or later the NDB's will be going there, too. Fazit: even if some remain today, don't count on them being there tomorrow. The future is all for SatNav (called "GPS" by some) which is cheaper both for operators and for users, and more accurate.
I read somewhere recently that the UK CAA require licensed airfields to have a notified means of location even for VFR airfields; the most basic of these means is to have an NDB on the airfield with or without DME or alternatively VDF, however some airfields have decided to de-commision their NDBs where they have a VOR/DME located not too far away, having discussed it with operators and found that very few actually use the NDB for its original purpose plus you have to pay for a license and regular maintenance or repairs (many are getting quite old) and VDF cannot be used effectively at FISO airfields as the AFISO cannot pass QDMs, only QDRs.