ATC IssuesA place where pilots may enter the 'lions den' that is Air Traffic Control in complete safety and find out the answers to all those obscure topics which you always wanted to know the answer to but were afraid to ask.
In general it is appreciated if you ask and also give your intentions i.e. left or right of track xx degrees for approx 40NM. Also do it well in advance, 20 miles or so. I will never refuse you to avoid Wx, but may level you off, if climbing or descending, for obvious reasons.
As for avoiding Wx into R, D or P airspace (active missile test range for example) a negative might be forthcoming: "If you avoid to the right you will die..." kinda thing, but an alternative will be suggested.
I would expect to be asked. I would never and will never stop you turning, but be aware that you maybe levelled off or "encouraged" to turn the other way. This would all be to avoid other traffic, last thing you need is an airmiss whilst avoiding.
Don't forget that WX avoidance is the thing that brings the highest workload for us. Your 20 degree turn to the right that is acknowlegded with a nice calm sounding "Turn approved" will be acompanied by a series of telephone calls as we coordinate you through other sectors, tell the mil and generally swear a bit.
In the busy sectors in the Uk then we would like a heads-up before you deviate from your flight planned route or assigned heading.
Something simple like "Request right 15 degrees to avoid Wx" If that suits the controller he will approve it & then will probably ask you how long you require that heading and to report when clear of the Wx.
Again once clear of the weather the controller would prefer a call to request re-joining your flight planned route, rather than just turning on your own. He may have other traffic also Wx avoiding that you need to remain on that heading against.
Wx avoiding is a very stressful time for ATC as the workload increases 10-fold. And as we can't see the weather on our radars at all then we are relying on the pilots to pass the info to us, so that we can try & help out other traffic behind you.
Basically communication between the pilots & ATC is the key to Wx avoidance.
At our Approach unit wx avoiding usually means leaving controlled airspace.That means change in radar service,watching out for 7000's or non squawking,military,gliders and all the rest in Class G.We have to use a lot of vertical separation,belt and braces.Best of all when there is a thunderstorm on 7 mile final and you can't see it on radar .I always want pilots to ask for wx avoidance but will not refuse.Gives me time to think of plan Z.
And as we can't see the weather on our radars at all then we are relying on the pilots to pass the info to us, so that we can try & help out other traffic behind you.
Which is utterly crap for ATCO's and pilots alike.....I am no big fan of ATC in the states, but at least they can see the weather we see.
"Plus, don't think we aren't wise to the old line of "Direct to xxxx would keep us clear"."
Well, in some cases it's true. Is it harder for you guys to clear us direct to a point than to have us on a heading? With a point you know exactly where we are heading and which track we are going to make good. On a heading anything can happen so I would have thought this is a good solution whenever possible.
As a Tower controller I hope I have an idea of when wx avoiding might be required, but I rely on the pilots telling me what they require and when as we have no idea of where the cells are.
It creates a lot of extra workload for the Tower as well (granted not as much as radar) but when every hold is blocked with all aircraft refusing to take-off due to a cell on climb-out, and they’re still landing, carnage ensues. So let us know nice and early what your requirements are and we’ll do our best to get you airborne asap.
It's pretty much what I expected to hear but had doubts about recently because of some colleagues responses to the issue. Most pilots tend to ask but quite a few recently informed during or after the turn. Plus it seems to be different even within the same airlines. It's a bit of a nerve wrecker after you've asked can the heading be kept and you see the aircraft turning off a heading in the useless direction 15Nm out without warning.
If you have spotted a path between a couple of cells you can bet the guy coming the other way has seen the same gap and wants to go through it as well. Ask first and ask as early as possible.
"It's pretty much what I expected to hear but had doubts about recently because of some colleagues responses to the issue. Most pilots tend to ask but quite a few recently informed during or after the turn. Plus it seems to be different even within the same airlines."
I see this all the time in my airline. For me, above FL95 we're in controlled airspace and anything we want to do has to be cleared by you guys. But still it's some kind of understanding amongst a few guys that they can "borrow" a couple of degrees left or right wichever they prefer without telling anyone Doesn't rhyme very well with my views but I'm just the co-pilot so what do I know...
Min separation in UK is 5 miles. TC is 3 miles. 2 aircraft on parallel headings 3.5 miles apart both borrow a few degrees without informing ATC. Could be interesting!
Deviation from normal track due wx is generally ok if told.....going left/ right and then asking or telling could be straight into an active danger area...or track separated traffic. we are here to help and would always seek to find you a solution.
Julian, I've never heard of an a/c asking to slow due to weather avoidance, just for turbulence or if weather at the destination has caused a backlog in the holds.
As I've said on weather avoidance threads before, always ask first. The London sectors are so tightly packed together now that unknown deviations can cause all kinds of trouble. The mass avoidance we had earlier in the year (discussed on another thread in here) proves the point exactly. We do flow our sectors when lots of weather is known so hopefully the frequencies shouldn't be too loaded, and taking a turn toward a rather large French danger area is the last thing I really want to try and co-ordinate, not having fighter control training and missing 3 Mirages going full tilt aint that easy.
Just out of interest given that the industry is so highly technological why on earth do ATCOs not have weather radar imagary sumperimposed on their displays?
It is surely not beyond the wit of man and would do so much to reduce workload in times of severe weather.
Just out of interest given that the industry is so highly technological why on earth do ATCOs not have weather radar imagary sumperimposed on their displays? It is surely not beyond the wit of man
Define 'weather'. Thats just one of the difficulties.
to turn the other way. This would all be to avoid other traffic, last thing you need is an airmiss whilst avoiding. 
.I always want pilots to ask for wx avoidance but will not refuse.Gives me time to think of plan Z.
