Can somebody explain European airway system naming (L, P, Z, T etc.) ?
Why? It’s aviation!
See page 88 of ICAO annex 11
In particular, it is useful to be able to tell RNAV vs non-RNAV routes in most cases. I don’t know how a designator within a category is chosen, i.e. why L and not M, N or P. Also it seems to be inconsistent from FIR to FIR.
Some countries such as Germany have gone further and designated T routes as arrival routes into a terminal area (not to be confused with STARs) and Y and Z being some sort of departure/arrival transition routes. For instance, if you fly into a larger airport on airways in Germany you normally end up on a T, Y or Z route. It’s documented somewhere in the AIP but I am failing to find that at the moment.
Also the RAD restrictions for these routes show what they were originally intended for but the RAD restrictions are very inconsistent (and frankly a mess as s result…)
Found it now in Germany AIP ENR 3.3:
Note 8: Purpose of ATS routes with T, Y and Q designators:
ATS routes with T, Y or Q designators are special feeder routes to be used as transition/access to connect SIDs and STARs of the designated aerodromes to/from the enroute network.
In detail the designators are used as follows:
– T routes indicate transitioning from the enroute phase to terminal operation
– Y routes indicate transitioning from terminal operation to the enroute phase
– Q routes indicate transitioning to/from terminal operation to/from the enroute phase.
I provided the textbook answer but would be equally curious how the airways are named in practice. E.g. there is a system to highway naming in most countries.
For instance, why does the airway designator change for some airways when crossing the London FIR boundary?
I searched throughout my atpl books and found very little information about this.
It has always struck me as a mess. I am not sure in practice the naming convention makes any difference.
wbardorf wrote:
For instance, why does the airway designator change for some airways when crossing the London FIR boundary?
So, so many things change when crossing the London FIR boundary 
I guess fewer and fewer of us remember the old Ambers and Reds 
Timothy wrote:
the old Ambers and Reds
Aaaah. Nostalgia.
I searched throughout my atpl books and found very little information about this.
I admire your optimism, in hoping to find “information” in the ATPL theory 
