Avoiding WX

[360 right]

Looking for info on what ATCO's are taught with regards to thunderstorm avoidance.

Do you expect to be asked permission or just informed?

[BlueSkye]

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.

[1985]

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. :eek:

[DTY/LKS]

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.

[throw a dyce]

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 :uhoh:.I always want pilots to ask for wx avoidance but will not refuse.Gives me time to think of plan Z.

[MancBoy]

Plus, don't think we aren't wise to the old line of "Direct to xxxx would keep us clear".

[haughtney1]

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.

[low n' slow]

"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.

/LnS

[MancBoy]

i was actually referring to an irish registered carrier who thinks that direct DUB would keep them clear

plus, i think it is better to use headings then i know exactly what you are doing so are therefore still in control

[Spangly]

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.

[360 right]

Thanks for the info.

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.:ugh:

[Arkady]

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.

[low n' slow]

"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 :eek:
Doesn't rhyme very well with my views but I'm just the co-pilot so what do I know...

/LnS

[Not-a-virus]

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!

[Julian Hensey]

Is slowing down speed wise ever used as a weather avoidance technique?

[45 before POL]

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.

[5milesbaby]

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.

[Doors to Automatic]

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.

[BDiONU]

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.

BD

[covec]

Definition of "weather" from an aviator's point of view?

That which could wrench your wings of at the wing roots!

Seriously: possible severe turbulence, icing, lightning strikes, unusual airframe stresses = not fun.

320 heart rates per minute not fun.

[throw a dyce]

Doors,
At Aberdeen we have a lightning detection system superimposed on the radar displays.This was after a 332 ditched after losing it's tailrotor due to a lightning strike.It gives a history of lightning,but how accurate is not known.However if we give the heads up about any activity,the choppers certainly give it a wide berth.

[Jerricho]

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?

The technology is certainly available........the system we use here in Canada allows for "layering" of information on the screen, and we have a piss poor weather overlay and a fairly good lightning display. However, the company won't shell out for a real-time weather feed to drive the overlay (so I'm told)

[BDiONU]

Definition of "weather" from an aviator's point of view?
Seriously: possible severe turbulence, icing, lightning strikes, unusual airframe stresses
And how would this type of 'weather' show up on radar? Radar does show precipitation.

BD

[BDiONU]

The technology is certainly available........the system we use here in Canada allows for "layering" of information on the screen, and we have a piss poor weather overlay and a fairly good lightning display. However, the company won't shell out for a real-time weather feed to drive the overlay (so I'm told)
I'm told that there is no real time feed to display precipitation (10 minute time lag in general) but its the other things that are not possible to display, turbulence, icing etc.

BD

[bookworm]

Define 'weather'. Thats just one of the difficulties.

Easy. Weather is "something I'm not going to fly through". ;)

Pretty much all the hazards that an aircraft is going to want to avoid are related to precipitation, though there are obviously difficulties in that the picture that the aircraft sees is not necessarily the same as what a ground based system would see.

That said, I remain stunned that UK ATC doesn't have some sort of precip picture superimposable. It might not be perfect but it would surely offer some clue that deviations around particular areas are very likely to be requested.

[BDiONU]

Easy. Weather is "something I'm not going to fly through". ;)
But does that apply to you personally or every pilot? Should ATC compel pilots to take vectors to avoid 'weather'?
Pretty much all the hazards that an aircraft is going to want to avoid are related to precipitation, though there are obviously difficulties in that the picture that the aircraft sees is not necessarily the same as what a ground based system would see.
As I've said previously what can be seen is precipitation but what it consists of is very difficult to know.
That said, I remain stunned that UK ATC doesn't have some sort of precip picture superimposable. It might not be perfect but it would surely offer some clue that deviations around particular areas are very likely to be requested.
And I remain stunned that people think there is some sort of magic radar out there that can interpret whether 'weather' contains icing or severe turbulence etc. etc. You sort of answered your own question anyway, ATC getting some clue that deviations may be requested. You know deviations are going to come when aircraft start asking for them, otherwise its not really possible to know whether any representation of 'weather' depicted on a radar screen is of the sort a pilot would want to avoid or not until you're told.

BD

[Max Angle]

That said, I remain stunned that UK ATC doesn't have some sort of precip picture superimposable.Yup, me to. Fly 30 mins across the North Sea to Holland and they have a good system which seems to match what you see on the aircraft radar very well. Saves a huge amount of RT time and helps keep the traffic flowing, ATC just vector you around most severe weather without asking as they can see the bad stuff quite clearly. At some point in the UK somebody made the decision not to have it and in my opinion they got it VERY wrong.

[BDiONU]

At some point in the UK somebody made the decision not to have it and in my opinion they got it VERY wrong.
Its still under investigation, as I have tried to make clear in previous posts its not as simple as it might at first appear.

BD

[radarman]

I agree with BD.

Some years ago I worked at a unit whose radar showed precipitation. One pilot asked if I could vector him clear of weather, and I gave him a nice clear course between two cells. 'Thanks' he said afterwards. 'that was the roughest bl**dy ride I've had in years.'

A few months later another guy asked if he could deviate due weather, and promptly flew through the heaviest clutter on my screen.

So it's no use relying on the clutter that shows up on the shorter-wavelength ATC primary radars. If ATC are going to have radar to show 'weather', it has got to be to the same spec as aircraft weather radar.

[javelin]

There is a huge difference between here in the UK and in the USA.

CAA/NATS seem to have gone down a route of screening out weather completely, whereas in the States, the en route controllers regularly advise you of precipitation ahead and give very good range and bearing info. When you get into the TMA, I never even think about weather in the States because the controllers are slick enough to vector you around what they can see on their screens.

In the UK, they seem oblivious to what is around and regularly ask you to point directly toward a cb.

Not the controller's fault - I believe it is the equipment.

Now, if we can stop the Americans from bleating about turbulence and ride reports all the time, we can have a quiet flight - that is the pilots, not the controllers :E

[galaxy flyer]

BlueSkye

Once told a JAX controller who denied use of military airspace (in C-5) that "tell that mil traffic, this mil traffic needs some of his space NOW" It worked!

[slatch]

At least in the US the NEXRAD radar is a major improvement over what we had for years. After using it for a few years it is obvious it is fairly accurate. Of course when an aircraft that is recieving data linked weather, requests to deviate they are looking at the same information the en-route controller sees. The data only updates every 6 or 10 minutes depending on the mode it is operating in.

There are still alot of coverage gaps, check out the coverage link on BendixKing's website.
https://www.bendixking.com/wingman/static/FIS/faq.jsp

For more information on NEXRAD

http://weather.noaa.gov/radar/radinfo/radinfo.html

[BDiONU]

When you get into the TMA, I never even think about weather in the States because the controllers are slick enough to vector you around what they can see on their screens.
In the UK, they seem oblivious to what is around and regularly ask you to point directly toward a cb.
Not the controller's fault - I believe it is the equipment.
How about the lack of airspace in UK to slickly vector flights around reported weather? ;)

BD

[anotherthing]

I'm with BDiONU with this - it's all very well having the facility to have weather superimposed on our radars, but how many times have you,as an ATCO, been asked for a turn by one A/C on a particular route to avoid weather, just to have the next A/C a couple of minutes (or less) behind, fly straight through the 'weather', even when the A/C are the same type..... you even get this happening between A/C of the same company, so it's not just SOPs that dictate what pilots want to do!

Pilots have weather radar and know how to interpret it to the standards required in their company SOPs.... we as ATCOs should let them get on with this, i.e. let them do what they are trained for, whilst they let us do what we are trained to do - (for example - don't use TCAS as a pseudo ATC radar :}).

If the weather is soo bad, we will be putting MDIs etc on to reduce the traffic to enable us to cope... having weather info on our radars would not change this.

When there is weather about, we have enough on our plates as ATCOS making sure that we keep A/C that would not ordinarily be traffic to each other, or indeed would not even normally be in our sector safely separated....
trying to be 'slick' and pass weather info to every pilot, or offer vectors to every pilot when a) they can see the weather themselves and b) it might not even be significant to them, can only make our job harder, or at least it will decrease our efficiency and distract us from our main task i.e. seperating A/C!

In TC, our GS suites have a weather radar so the GS can give us an indication that there is weather about, and give us the general trend of it.

At Swanwick in the AC OPS room, their may be an argument that as every position is manned by two ATCOS (TAC/Planner), then the planners display could have weather super-imposed on it - but merely for information.

Just my two pennies worth... I think th esystem works as it is, but it is dependant on pilots ASKING for deviation, not telling us they have commenced it!

[Julian Hensey]

Well I am sure there will be invented soon a way of downloading the real time picture from incoming aircraft. Say you have two or three around and take a snapshot picture of what they see on their radars and use computer wizardry to combine it and upload it into ATC somehow.

Another idea might be being able to place on the radar view a marker so when incoming says "big cell 20 miles north of field about 320 degrees" you can temp mark it on the radar display and it removes itself after a so many minutes live time. Maybe it is already done.

But, and the big but is, if ATCO's take on responsibility for providing weather information based on their display then if it goes wrong you can depend on the lawyers to start shifting the blame from pilots to ATCO's for any incidents arising out of wrong vectors. Probably best stays as is!