Mozart From Luxembourg, joined Aug 2003, 2297 posts, RR: 12 Posted (10 years 3 months 1 week 1 day 7 hours ago) and read 3539 times:
Since France's airway system is more North-South oriented than East-West, I was wondering wether the odd vs even flight level distinction is the same as in other countries (odd from 0 to 179 degrees, even from 180 to 359 degrees. right?), or whether the split is made at 90 respectively 270 degrees?
I am sure someone like Pihero could fill me in on this. Thanks in advance!
Pihero From France, joined Jan 2005, 4990 posts, RR: 78
Reply 2, posted (10 years 3 months 5 days 8 hours ago) and read 3450 times:
You are quite right the semi-circular rule even Westbound/odd Eastbound applies in the RVSM airspace over France.
That said,the system considers not the segments of an airway, but the whole length, thus avoiding numerous level changes when the orientation of the route oscillates either side of the north/south compass.
For safety reasons,when two airways passing over a common waypoint diverge from each other,the system will keep them in the same odd/even level table.
This is the case for awys UM731, UZ131, UN855, UN869, UQ169, the headings being respectively 147°, 163°, 181° 236°, 240° ,all originating from OLRAK ( this waypoint is 20 Nm NW of Mende.The reason is the importance of the traffic from Paris on the UN855 which forces the westbound UN869 to adopt the odd list.( Airway UN869 comes all the way from Germany)
Hope it helps.
And anyway if you came to see me, I would give you a tutorial on air nav maps and approach plates.Free !
looking forward to hearing from you soon,