bookworm wrote:Actually, if you have PBN equipment on board (most likely IFR GPS) you are allowed to use it as a sole navigation source in place of any navaid during any phase of the flight except approach (where you can still use it, but underlying navaid takes precedence in case of discrepancy and must be monitored).
Where do you get that from then?
French AIP goes as far as to specifically say it is allowed "However, some equipments on board enabling information to be used from radio navigation aids can be replaced by RNAV systems when it was shown that the performances of these last ones comply with criteria of replacement notified to users by the way of the aeronautical information.",
UK AIP doesn't go as far to say it is allowed directly, but it does not prohibit navaid substition and in case of class A requires use of RNAV. (still not updated to say PBN), Also, from ICAO manuals
"1.4 USE OF FLIGHT MANAGEMENT SYSTEM (FMS)/
AREA NAVIGATION (RNAV) EQUIPMENT
1.4.1 Where FMS/RNAV equipment is available, it may be used to fly conventional procedures provided:
a) the procedure is monitored using the basic display normally associated with that procedure; and
b) the tolerances for flight using raw data on the basic display are complied with.
"
With UK having notified difference "Additional requirements:
the conventional procedure must have been inserted into the FMS from a recognised database and cannot be manually loaded or modified by the crew other than to follow ATC instructions;
after the procedure has been loaded into the FMS as above, it must be cross-checked against the published conventional procedure before any attempt is made to follow the procedure using the FMS."