Originally Posted by
tdbristol
I must admit I have not had good experience of using NDB approaches in real IMC. Fortunately I have only used them when training (I have an IR(r) and FAA IR).
One on occasion coming into Filton rwy09 (shows how long ago it was) I was in real IMC; an instructor with me as it was a re-val test. I was flying it well - as the instructor agreed; needle just where it should be.
However, on shortish final ATC told us to abort and go around - we were 30degrees off track [still in solid IMC].
The weather was not that bad - only stratus cloud; no embedded CBs (maybe some CBs a distance away) - and the conclusion was coastal refraction plus the distant CBs had an effect (had seen coastal refraction effect at other times under the hood). Had to do an SRA in the end, which was not a problem, but it showed me how poor NDB guidance could be.
Second time was at Cardiff, went round the hold 10 times (!) in solid IMC, waiting for Easyjets to land etc. Another re-val test. Again the instructor agreed the ADF needle was spot on. Still on solid IMC we began the approach - all good - yet ATC told us to abort and go back to the hold as we were too far off track. (Ignored the ADF, just used the DI and timed the turn to do an ILS approach in the end.)
In both cases I would have had real problems if I had tried to land using the NDB alone.
I find it extraordinary that GNSS cannot be simply approved as an overlay on the same approach path as an existing NDB approach; surely all the issues of terrain clearance etc. have already been dealt with on the NDB approach? And GNSS is more accurate and reliable and not prone to NDB effects from a local CB or coastal refraction, and easier to interpret.
If there had been no NDBs and someone suggested NDBs now as an approach aid I would imagine that there would be many comments about its unreliability, safety issues etc. (certainly compared to GNSS) - not least from the CAA themselves.
I am not an instrument-rated pilot (I gave up in the middle of my IMC training almost 30 years ago) but I think this account tells it's own story.
As CJ1234 said, "Quite agree. the NDB (approach) should have gone the way of the dodo decades ago."