Mr FD
Respectfully suggest a quick peak at PANS-OPS Doc 8168 -OPS/611 or for easy reading JAR-OPS 1 - Minima Specification - say for Cat 1 Mins and review PEC (Position Error Correction) For really snoozy reading - pressure instruments ...... installation errors....static tubes....alignment......zzzzzzzzzzzzz.
Gen in POH for A/C type. Stick to NDB approaches until fully satisfied on this matter
