Originally Posted by
Big Pistons Forever
The last NDB approach I shot for real in IMC without some sort of GPS track guidance was 1994. The technology is 90 years old and ground stations are disappearing rapidly, I don't understand why this is still being taught.
Big Pistons Forever
My question would be why is an airline not using the safest most accurate nav aids for their operation.
We fly NDB approaches regularly in Russia without GPS overlay, why you ask, well simple their mapping structure is not aligned to the WGS84 which is the basis of GPS therefore if you use your GPS you won't be in the place you are supposed to be.
Beagle
I was once told that old Soviet procedures used 2 NDBs aligned with the instrument RW. With 2 x ADF receivers and a twin needle display, all the pilot had to do was to turn to keep the needles aligned. After passing the 'outer', the indications became even more intuitive - same after passing the 'inner'. Cheap and simple - if the pilot had been properly trained and was in current practice.
Yes nearly every NDB approach in Russia has two NDB beacons, the last beacon on the approach is always at minimums and you will always be tracking towards it therefore greater final approach track accuracy as you approach minimums, plus as the needle swings its time to go-around if nothing seen.
ATC