Tops enroute to Switzerland/South France

[VORTIME]

Hi there,

Are there any rules of thumb or general advise on getting VFR on top (assuming IFR SEL flight) from Dublin to Switzerland or Cannes? What would one normally expect visa-a-vie altitude / weather en-route?

Also, is there any easy method of doing weather planning of a relatively long distance?

Cheers
VT

[IO540]

Vortime

You have a PM.

I think you mean VMC on top.

In general it's hard to forecast cloud tops because they are the result of processes which can't be precisely measured or modelled. Whereas bases can be got from TAFs/METARs usually.

The UK Met Office (very kindly, in the interests of safety of course :yuk: ) does not release its 3D model data; they sell it to commercial weather providers who would be most unhappy if it appeared on some free website.

There are two ways I know of: one is the US-run GFS model which can be accessed via many websites e.g.

http://www.arl.noaa.gov/ready/cmet.html

and which had forecast skew-t diagrams somewhere, and the other is a Univ of Basel site I use

http://pages.unibas.ch/geo/mcr/3d/meteo/

which, under Animated Soundings, has a tephigram which is a similar kind of thing.

IFR flight planning involves working out a route acceptable to Eurocontrol (CFMU) at levels which your plane can fly at, and oxygen requirements come into it too.

I normally stick in a flight plan at FL100-130 if the weather is nice and one can always stop climb early (routing restrictions excepted) or ask for a further climb (never been refused). Normally I go for a level at least 3000ft above any tops forecast. You don't want to sit in IMC at -5C :) Icing is a major issue and must be avoided as far as possible in the planning stage.

There is no easy method. You need to know where (on the internet) you can get weather data, how to make sense of it, and you need a capable plane to get above the clouds. In Europe, most airway MEAs place you either bang in the cloud or just above it, rarely below it, and this is true all year round, and you can pick up ice any time of the year.

The above is a very short answer to a very short question which deserves a very long answer!

[IO540]

Yes, very good.... no PIREPs in Europe unfortunately. Well, you can make the report but the info won't be passed on to anybody.

[bookworm]

VFR on Top (not VMC) is common here as a means of being able to pick your own altitude if ATC are unable to accomodate you. You then fly at a VFR altitude of your choice instead of the assigned IFR altitude.

There's no equivalent in Europe.

Presumably IFR flights and VFR-on-top flights 500 ft above or below are considered separated? Or perhaps in class E such separation is not required?

[mm_flynn]

Presumably IFR flights and VFR-on-top flights 500 ft above or below are considered separated? Or perhaps in class E such separation is not required?

In everything up to Class A (but not including obviously) VFR traffic is deemed seperated from IFR if there is a 500 ft altitude difference. (AIM Section 2 - which I know isn't law:) ). I believe that VFR on top is separated in basically the same way - but stand to be corrected by a US ATCO. In general the US uses much more liberal separation rules for IFR vs. VFR than the UK, which I suspect is why it is so much easier to manage zone transits.

[DFC]

VFR on top is allowed and is common in Europe including the UK.

However to fly VFR one must be operating VFR i.e. one must cancel an IFR flight plan if one exists to continue VFR.

VFR on top in Europe happens in 3 ways;

1. VFR departure and climb, operate on top at some stage enroute and descend under VFR to destination.

2. VFR departure and climb, operate on top enroute and change to IFR at some point prior to descent.

3. IFR departure and climb. Cancel IFR at some stage enroute and operate VFR on top followed by a VFR descent and landing.

The UK causes some problems on routes that tansit the airspace because of the large ammount of class A airspace.

However, provided that the pilot has a valid IR, they can cross class A airways IFR in VMC (subject to ATC clearance) without a requirement for the aircraft to be IFR equipped.

For cruising levels, most European countries require VFR flights crusising above 3000ft to comform to the ICAO table of cruising levels - East = Odd+500 and West = Even+500. The UK is different in this respect by only recomending that VFR lights conform to the international standard.

If you are going to use FL105 and FL115 as the cruise levels then the European Significant Weather chart FL100 - FL450 will provide you with an uncluttered forecast showing the cloud base and top levels.

Other more local charts are available for lower levels and these will also show the forecast tops.

If one looks at todays 1200z chart, one can see that provided one stays ahead of the front over Ireland, one can fly from Dublin to the South of France and be above the tops all the way at FL100+

However, remember that one must be very sure of the weather at both destination and alternates +/- about 3 hours of ETA permits VMC descent from cruise level unless one has an IR, and an appropriately equipped aircraft, and the appropriate charts, fuel etc etc.

Regards,

DFC

[IO540]

However, provided that the pilot has a valid IR, they can cross class A airways IFR in VMC (subject to ATC clearance) without a requirement for the aircraft to be IFR equipped

Reference please.

For cruising levels, most European countries require VFR flights crusising above 3000ft to comform to the ICAO table of cruising levels - East = Odd+500 and West = Even+500. The UK is different in this respect by only recomending that VFR lights conform to the international standard

In my experience, there is little difference between the UK and Europe. Some ATCOs like you to fly the proper levels, most don't care. In most of Europe (outside the UK) there is close to zero GA traffic anyway.

[Kirstey]

In everything up to Class A (but not including obviously) VFR traffic is deemed seperated from IFR if there is a 500 ft altitude difference. (AIM Section 2 - which I know isn't law:) ). I believe that VFR on top is separated in basically the same way - but stand to be corrected by a US ATCO. In general the US uses much more liberal separation rules for IFR vs. VFR than the UK, which I suspect is why it is so much easier to manage zone transits.

This isn't the case at all.

Class A no vfr

Class B VFR seperated from VFR and IFR, IFR seperated from VFR and IFR

Class C I seperated from I & V and V seperated from I given info on V

Class D I seperated from I & V and V given info on I and V

Class E I seperated from I and given info on V and V given info on and I and V

I being IFR etc etc

[slim_slag]

VFR on top is allowed and is common in Europe including the UKYou seem to be confusing 'VFR on top' and 'VFR over the top'. Two different beasts in the US, what you are describing in the rest of your post appears to be what the FAA would call 'vfr over the top', not the 'VFR on top' the rest are talking about.

In VFR on top in Class E in FAA land, the guy cleared to fly VFR on top is responsible for visual separation from planes and clouds, but must remain above the MEA (or MOCA if applicable) as he is still IFR and IFR minima apply. The controller will give him a 'flight following' type service, though will separate other IFR traffic from him. Also the controller will provide sequencing separation etc.

[bookworm]

VFR on top is allowed and is common in Europe including the UK.
However to fly VFR one must be operating VFR i.e. one must cancel an IFR flight plan if one exists to continue VFR.

There's a terminology difference. ca_flyer (and I assume VORTIME too) is refering to:

IFR Clearance VFR-on-top (https://www.faa.gov/ATpubs/AIM/Chap4/aim0404.html#4-4-7).

What you describe as "VFR on top" in Europe is colloquially described as "VFR over the top" in the US.

[mm_flynn]

This isn't the case at all.
Class A no vfr
Class B VFR seperated from VFR and IFR, IFR seperated from VFR and IFR
Class C I seperated from I & V and V seperated from I given info on V
Class D I seperated from I & V and V given info on I and V
Class E I seperated from I and given info on V and V given info on and I and V
I being IFR etc etc
Kirstey, my comment was in reference to Bookworm's question about VFR on top separation in the US. There is a proper IFR clearance called VFR On Top in the US - which IS an IFR clearance and is NOT the same as flying VFR above a cloud layer (as the term is used in Europe). As far as I and apparently Bookworm are aware this clearance is unique to the US.
The separation rules for IFR and VFR are as you state, however, I believe that UK airtraffic generally feel the need to maintain IFR separation minimums for IFR against VFR traffic in Class D airspace, including a 1000 foot separation. In the US that is definitely not true, as 500 ft separation of VFR vs. IFR with 0 lateral separation is separated in Class B,C,D,E even if the VFR flight is receiving Separation and Sequencing services from the Class B Tracon.
The bit I don't know about is if VFR On Top (the IFR clearance) is separated from IFR using the IFR v. IFR rules or is treated as a VFR flight for separation.


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Obviously a bit late on pushing submit

[slim_slag]

The bit I don't know about is if VFR On Top (the IFR clearance) is separated from IFR using the IFR v. IFR rules or is treated as a VFR flight for separation.As I said, the "VFR on top" aircraft is expected to separate itself from IMC and other traffic. Any IFR traffic will be separated by the controller. However, as I understand it, the controller can issue an alternative clearance if they consider it necessary to ensure separation. So essentially they can cancel your VFR on top and put you back on standard IFR.

That's how I believe it works.

[IO540]

This American stuff is one of the things which one has to learn for the FAA IR, only to forget it immediately afterwards.

In Europe, if you have IFR privileges, you would rarely bother to go VFR. VFR is nothing but hassle. The moment you go VFR, instead of getting sent to nice convenient airways intersections ATC might send you to useless VRPs which cannot be found on anything other than VFR charts, but you are above the clouds... You also have to dig out the VFR charts so you don't wonder into controlled airspace without a clearance, into some danger area, restricted area... etc. Been there and done it, 700nm legs across Europe under VFR, at FL160 above solid clouds. The only exceptions to the foregoing I can think of are

- wanting to get below the clouds for a better view, but airway MEAs are often there for a reason... like mountains :) so one needs to do this carefully since, once VFR, all bets are off when it comes to obstacle clearance

- avoiding IFR route charges on 2000kg+ planes

But it's funny how far off this thread can get from the original Q which was on IFR flight planning strategy.

[DFC]

Please ignore all the FAA rules with regard to VFR on top or VFR over the top or anything like that in Europe.

In Europe, in the enroute airspace, one is either VFR or IFR. If IFR then regardless of the weather, the IFR rules apply and will be followed. If in VMC, even if that is over 8/8 cloud cover, one can cancel IFR and continue VFR. In that case one is totally VFR and must remain VMC and one must comply with all the VFR rules.

Obvously, if in class A airspace, one can not cancel IFR. If one is in Class B, one can cancel IFR but it will simply add a restriction to the flight by requiring it to remain VMC as ATC will issue level and routing instructions for separation and clearances required for everything.

It is only when one flies in class D and lower that it can be worthwhile cancelling IFR and proceeding VFR.

Perhaps I did not make that clear in my original post.

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IO540,

Check out the Enroute section of the UK AIP under General Rules for the requirements regarding flights crossing airways.

You will also find if you check that VFR flights outside the UK are required to fly at an appropriate level when cruising above 3000ft AMSL or some other specified height depending on the country.

This is very important in places like France where VFR flights are crusing in class E airspace without any requirement to talk to or be coordinated with the ACC seector controlling the IFR traffic.

I do not want to be flying IFR at the correct level and have to worry about some prat playing with their GPS who has not bothered to plan correctly and is claiming to be VFR but operating at an IFR level. people like that often claim to be VFR when in IMC enroute :(

Regards,

DFC

[IO540]

Actually the fact that Europe doesn't have the USA's VFR on top or VFR over the top, VFR under the top, VFR in the middle of the top, etc etc options is the easy bit :)

Here, a pilot may not be able to fly VFR without sight of surface if his PPL was issued by one of several countries in the world. The UK is one of them, and I am still looking for a complete list.

Only if you get an IR (or the UK IMC Rating) is this restriction removed and your privileges then expand back to the basic ICAO VFR license privileges which allow VFR out of sight of the surface.

Most UK PPLs thus cannot fly out of sight of the surface, anywhere in the world.