Hi there,I've recently come across some BRNAV style Standard Instrument Departures (at Barcelona LEBL) and I have little idea what they are.Can ayone explain them to me and could you tell me if a BRNAV departure better than a standard procedure, when flying jets like the 737, 757 or A320's.Also whats PRNAV and is that better or worse than BRNAV.ThanksDaniel

BRNAV=Basic Area Navigation StandardsBasically it allows navigation along a desired flight path as long as it stays inside the coverage area of the associated navigation aids us are using such as VOR, NDB etc... or within the limits of the capability of self-contained aids, or a combination of these methods.

BRNAV also includes GPS units like the GNS series too. Capable of +/- 5nm 95% of the time. This usually requires something called RAIM (Receiver Autonomous Integrity Monitoring) that requires a minimum number of stellites including reserves. Unreliability is something FS doesn't model unfortunately. BRNAV is required for all IFR flight in airways above FL95 in Europe now.PRNAV is Precision RNAV. Capable of accuracy of 1nm 95% of the time. This usually achieved by comparing and combining GPS, IRU (Inertial Refernece Unit), VOR and DME positions using priorities and ignoring those that place a fix outside of tolerances of the others.