GPS vs NDB (does NDB really meet RNP)?
I was reading a recent CAA publication which outlined the RNP for approval as a primary approach aid - and all of the reasons why the current GPS system does not meet these requirements. After monitoring the NDB 20 approach into Shoreham (with 35 knots declining to 20 on the surface from 280 and very gusty) on the GNS430 I thought - does this NDB approach meet the RNP requirements.
With the impact of shore line and mountain refraction, random swings from some nearby CBs and other interference and reasonably complex pilot interpretation to reflect the shifting winds (at least complex compared to the GPS or a VOR) does this system really deliver the RNP standards (and certainly is the GPS less reliable)
Any thoughts on the question.