Denti
This is from Airbus.
KNOWLEDGE - POSSIBILITY TO FLY SOME NPAS WHEN THEIR REFERENCE NAVAID IS UNSERVICEABLE. (On behalf of STL). In this case, the approach (VOR, VOR/DME, NDB or NDB/DME) is flown in a similar way as an RNAV approach.
However, as mentioned in the FCOM, the operator has to submit for an approval to their National Authorities.
The prerequisite from our point of view is that the airline fulfills all the operational requirements to fly RNAV(GNSS) approaches and it is even better if the airline is already approved to fly RNAV(GNSS) approaches. Therefore, the first step is for the airline to contact their national authorities to discuss this possibility.
From an operational point of view, we would recommend that the following elements are fulfilled:
• The operator is approved to fly RNAV approaches.
• The approach procedure is coded in WGS 84 in the Navigation Database.
• The protection areas of an RNAV procedure are always inside the protection areas considered in the original procedure (NDB, VOR), or there is no obstacle.
• FCOM limitations and SOP for RNAV approaches are observed.
• Specific requirements as imposed by the authorities