French/Spanish/Swiss FL assignments

[FF35Pilot]

Hi,
I need someone to clarify how France, Spain and Switzerland separate flights.

In most of Europe - Flying East you use an Odd FL
Flying west you use an even FL

However, whenever going through spain, france or switzerland, I get told to change level (this is a flightsim)

Do they use a complete reversal of the trend, or do they use a different rule whereby the FLs are assigned on heading 270 thru 089 and heading 090 through 269 (or similar)

Thanks. (Wikipedia has failed me here)

[Guy D'ageradar]

Sounds like switching from RVSM - to non RVSM airspace to me.

[Blockla]

Also various countries are subject to FLAS (Flight Level Allocation Systems) such as across the Atlantic, these change 'standard levels' at various times of the day in order to accommodate more flights in a particular direction.

[UpperATC]

Were you also entering or leaving Italian or Portugese airspace? Because...

Italy and Protugal, have north/south FL "orientation". That means, that some of their neighbouirng countries (ATCs) will probably have to assign a different (non-standard) FL before the border (airspace border).

Also, like mentioned above, FLAS are the reason. Due to small portions, corners of airspace here and there, where many routes are crossing, merging, converging, from east to west, and south to north - it is sometimes better to have non-standard FL at least until the acft leaves that area. It is a tactical agreement between, ANSP, for safety and efficency.

Guy D', non-RVSM in W Europe? :ok:

[FF35Pilot]

Yeh I thought it was like north/south instead of East and west, but what about switzerland?

And I know about Oceanic airspace, every morning westbound levels normally 300 - 390 (including every 1000ft)

And the same eastbound in the evenings - they don't have to worry about separating opposite direction flights because there's never normally a plane flying east the same time as a westbound, and as the NATs are geared to provide both routes the fastest flight time, (i.e. east bound finding the gulfstream, westbound avoiding it) the tracks never usually cross over any way.

[erikwachters]

Hello,

I can confirm that those FIRs have indeed other standard FL. South is odd and north is even.
So if you enter LFFF FIR from EBBU FIR for example ATC will put you on an odd FL.

Erik

[eastern wiseguy]

Folks

However, whenever going through spain, france or switzerland, I get told to change level (this is a flightsim)


The lad is playing a game on his pc.

[Crazy Voyager]

You'd be suprised how many people on here enjoy a bit of flightsim. Having said that fs questions would imo be better somewhere else (such as the 'questions' section, or even better the vatsim forums).


Rgardless, Erik and UpperATC have already answered the question.

[FF35Pilot]

I just figured if I put it in the real ATC forum there'd be someone here who does this for a job - and knows what they're talking about.
Thanks for the clarification.

[mikk_13]

It really just comes down to air space design.

If you have a corner parts of a sector that has tracks coming from 2 different FIRS, often there will be a change to an odd or even lvl to reduce the amount of separation involving 3 sectors in 3 different centers. You could imagine the co-ordination required in these situations, eg lvl changes, turns etc.

Or it maybe a busy route with a crossing route coming from another center with the same standard lvl, so to reduce workload for the planner controller the standard lvls are changed.

There a couple of examples I know of, these are going from Rhine FIR to Swiss, and Rhine to Malmo. You should always remember that in europe there are usually 2 controllers working one position, one planner with the other sectors, and one talking to captain awesome. So if the frequency is quiet, it some times does not mean the planner is not.

[UpperATC]

FS35Pilot - nothing wrong to ask here. You will always find someone to answer a 'proper' question properly. Even if it's coming out of FS world, and related to ATC.

For additional understanding, how complex airspace and FL allocation design is working have a look at the link from skyguide:

http://www.skyguide.ch/fileadmin/user_upload/publications/others/ERC_Upper_WEF28JUN2012.pdf

You will see small grey writing near those route lines. EVEN, ODD... Sometimes different than 'normal' orientation. But even that can be subject to ATC tactical decisions and planning.

Hope that helps.