Descend due to faster traffic behind??? [Archive]

sabenaboy

25th Jul 2006, 12:01

There I was yesterday evening, cruising at FL 370 in Croatia airspace on my way to Heraklion airport.
Suddenly Zagreb was asking traffic behind us (heavy, same level) to report Mach number.
They replied .82 and we replied .78 after being asked the same question. Neither the heavy or ourselves were able to climb due to high weight. Then the heavy traffic behind us informed with ATC if they shouldn't reduce speed. ATC told them that wasn't necessary, because he would tell the traffic in front (we) to descend. ATC then informed us that we had to expect descend a few minutes later due to traffic behind catching up. I let ATC know that due to weather in front of us, we preferred to stay at FL 370 if possible in any way. 10 minutes later we were instructed to descend to FL 330! After insisting we were allowed to descend to FL 350 i.s.o 330.
Here's my question: Isn't it very unusual to make traffic descend because the following traffic is catching up? I would think it is more logical to tell the traffic behind to change level or to reduce speed, rather then making the first traffic move out of the way for the faster one. I have often been told to descend because of converging or crossing traffic, or when I was catching up slower traffic myself, but I can't remember having to descend for faster traffic behind in the last couple of years.
Are there any rules or guidelines for ATCO's in situations like this?

PPRuNe Radar

25th Jul 2006, 12:20

One consideration might be the destinations. If the faster traffic is going a lot further then it makes sense to get the other traffic below it, since it will be descending first anyway.

biffo170

25th Jul 2006, 14:25

I let ATC know that due to weather in front of us, we preferred to stay at FL 370 if possible in any way.
Just one theory for the descent might be because of this weather. When there are CB's around it it much safer for the acft to be at different levels (from an ATC point of view). That way they can be free to avoid weather at their discretion, after asking ATC of course :ok:
Another reason could be that there was a back up ATC system in place which perhaps requires vertical seperation.
There could have been other crossing traffic you were not aware of?
You are correct to say what happened is not the normal way of dealing with the situation. However, is there such thing as a 'normal day' in ATC?

BOAC

25th Jul 2006, 15:27

Well, in my experience that is EXACTLY the 'normal' procedure. presumably you were shorthaul, and if you could not increase to 0.82 then apart from massive vectoring - which may have been a problem in that part of the world, it is 'down you go'.

One of the penalties for being a 'slowcoach':)

DFC

25th Jul 2006, 16:50

I let ATC know that due to weather in front of us, we preferred to stay at FL 370 if possible in any way.

So you were unhappy to descend due to the weather ahead..........but you were happy for the aircraft behind to be descended into that weather?

If I was behind you and heard you say that the weather ahead precluded a descent, you can bet your life that I would not volunteer to descend.

Basically the common way this is handled is as said previously, the aircraft with the closer destination is descended. Form a pilots point of view this makes sense. The aircraft with the closer destination will have a lower percentage of flight time remaining spent at a less favourable level.

You insist on maintaining the level and refuse to go down, the heavy enters the hold!.......you really better hope that the Heavy Captain agrees with your asessment of the weather!! :)

Regards,

DFC

Stan Woolley

25th Jul 2006, 18:27

sabenaboy

I would have been unhappy if that happened to me.

Contrary to the posts above I would normally have expected you to increase to .8 and the heavy to reduce to .8 and both maintain level.( Assuming it's possible)

You had the level and were ahead of him even if he is a 'heavy' going wherever - tough titties- you have your own problems to deal with and Heraklion and back is hardly a jolly night out! You are not exactly at TOD over Croatia.

Let him descend and then climb later I say. I accept there may be other good reasons for it happening the way it did but just 'cause he's a long haul heavy should not necessarily give him right of way IMHO.

DFC My assessment of the weather is none of any other Captains damn business. ;)

Loki

25th Jul 2006, 19:33

Sorry, it`s not a first come first service. No one "has" a level as someone put it, and the decision to allocate different levels to different aircraft to resolve a separation issue remains solely with ATC (factors affecting that decision usually include requested and or cruising levels). Obviously we want to do our best for everyone, but that means having to give a little sometimes.

Spamcan defender

25th Jul 2006, 20:19

Wow, I take it that this is a non-radar environment :eek: . I mean, in the UK, youd be slapped on headings and everyone would be happy. I suppose the fact that the controller is asking Mach No's etc probably means its procedural. Sorry, I mean I HOPE its procedural LOL.

Spamcan

Loki

25th Jul 2006, 21:04

Spamcan defender:

Of course, if space and or time permits, vectoring may be a solution.....it would seem not the most appropriate one in the case quoted. I`ve applied mach numbers to aircraft in the cruise lots of times in a radar environment BTW.

5milesbaby

25th Jul 2006, 21:54

Not forgetting also that if you are exiting the UK airspace then I know of no agency other than (rarely) Maastricht that would even consider accepting 2 aircraft on the same route at the same level on headings.

If that was me controlling then I would consider the options and then the final choice would be to descend the aircraft closest to destination, it is really as simple as that sometimes.

Scott Voigt

25th Jul 2006, 23:31

If we have the ability to move an aircrafts route we do it, but if not due to traffic or other issues, then yes one of you are going to get to move. It's controllers choice on who gets to do so. Sometimes we pick the slower if there are more than one faster behind at the same altitude, but we ALWAYS look for who is landing first if we are going to have to take one down...

As was mentioned in one post, if there is weather out there, you don't want to have folks on parallel vectors due to the deviations. They just don't work well...

regards

Scott

PPRuNe Radar

26th Jul 2006, 00:16

Have to agree that Scott has it on the button .... if only my RT was good enough for the US (plus of course all the nationality stuff), I'd be on exactly the same wavelength :ok:

Knackers

26th Jul 2006, 04:50

AirNoServicesAustralia

26th Jul 2006, 06:32

As Knackers says the priorities in Australian documents state that the aircraft first using the level gets priority, but surely it comes down to what is best in the bigger picture. If the possibility of weather diversions precludes the use of radar headings, then vertical is the way to go. Also it is risky to peg aircraft on speeds when in known areas of bad weather because aircraft may need to divert or reduce speed due turbulence, neither good options when the aircraft are at the same level. If two aircraft are going to be on the same route and subsequently the front aircraft is going to need to descend for landing while the following aircraft is going to continue overflying, then it is bad controlling to push down the overflyer, because then you have to somehow get the lander down. If by the time the lander needs descent, the overflyer has caught up and is under the lander, it not only makes more work for the controller, but makes the lander unhappy when his descent is held up in addition to being vectored clear to facilitate descent. Without knowing all factors, ie. possible other converging traffic, radar coverage etc. , I think the controller may have well made the correct decision. Bottom line is the controller with all information at his disposal made the call that he made, and he certainly had more information at his disposal than either pilot had.

Knackers

26th Jul 2006, 06:41

Bottom line is the controller with all information at his disposal made the call that he made, and he certainly had more information at his disposal than either pilot had.
Definately agree with the bottom line.

sabenaboy

26th Jul 2006, 08:03

So you were unhappy to descend due to the weather ahead..........but you were happy for the aircraft behind to be descended into that weather?
If I was behind you and heard you say that the weather ahead precluded a descent, you can bet your life that I would not volunteer to descend..........
..............
You insist on maintaining the level and refuse to go down, the heavy enters the hold!.......you really better hope that the Heavy Captain agrees with your asessment of the weather!! :)
Regards,
DFC
Howhow! I'd be the last one to send someone else into bad weather! With CB's around, I prefer to keep lateral AND vertical seperation to the weather. It think safety and passenger comfort were more important in this case then the heavy traffic having to fly less then optimal speed!

Why not simply ask the Edelweiss A330 (That's what it turned out to be) to slow down! That's what he had proposed himself already! (see my first post) I increased to .79 myself.

And when we finally had to descend, we were told to descend to FL 330. Only after insisting did the ATCO allow us to maintain FL350 with a speed of .78 or more and the traffic behind (also an A320) with a max speed of .78.
I think it just was a controller who doesn't like to give speed instructions.

Apparently in some countries, you will have to descend for traffic catching up on you and in some other ATC regions you will be allowed to keep your level. Anyway having to descend over Croatia with destination Heraklion made me (a little bit) unhappy!

sabenaboy

26th Jul 2006, 08:17

Bottom line is the controller with all information at his disposal made the call that he made, and he certainly had more information at his disposal than either pilot had.

I definitely disagree with this line.

We in the cockpit are the last in line when it comes to responsibility for the safety of the flight.
I saw the CB's ahead and the lightning with my own eyes and on my primary flight display. I doubt that the ATCO had weather available on his screen.

I'm pretty sure that in an area, where I believe ATCO's are probably better trained then in Croatia, another solution would have been found then me having to descend 4000 ft in an area with Cb's.

fourthreethree

26th Jul 2006, 08:45

Yes you hold the ultimate responsibility for the safety of the aircraft, and you have the right to refuse an ATC restriction or instruction if you feel it puts you in danger. But that also applies to the pilot who could also refuse, or change his mind, over a speed restriction. There is no general rule so far as I am aware that states any aircraft has priority over keeping a level, and the way I was trained was to maintain safety at all times, in adverse weather conditions I would opt for level separation over speeds or vectors every time. If that means a level change for somebody a long way from destination, than as somebody put it earlier, tough titties! However I agree that a descent of 4000 feet into cb's is more than a little bit overdone, I dont know....is Croatia ACC RVSM airspace? Was F360 available? Also, if F350 was only available also with a speed restriction then why not F370?

The real point is this, as was already mentioned....only the controller is in touch with the entire traffic picture, only he is qualified to make the call on what is best for separation purposes. There could be other traffic to affect you, the controller cannot explain the entire radar picture to every pilot. Also, cb's add to a controllers workload exponentially, its a case of make a decision thats safe and stick to it, you dont want to be monitoring too many situations (hence my propensity toward level separation) Sure you have better weather info available to you, and you pointed that out, so an alternative solution was found. Job done.

Understand you getting *slightly peed off with the descent, but ultimately the guy did his job and you reached your destination safely, its all about teamwork, not throwing your toys out the pram because you didnt get what you wanted.

sabenaboy

26th Jul 2006, 10:58

Apparently this was the situation to begin with:
1. myself (A320) at FL370 with .78
2. A330 at FL370 with .82 catching me up
3. A320 with .78 at FL350 close behind me.
All 3 of us on the airway inbound to Dubrovnik.

When I was informed to expect descend, I replied:
"Due to weather we would like to maintain FL370 if possible"
ATC: "roger"

10 mins later I was instructed to descend to FL330:
"Roger, descending FL330, Confirm that FL350 is also not available?"
ATC: "Standby, traffic ABC123, report Mach" (.78 was the answer)
And then I was allowed to maintain FL350 with both of us on speed restrictions.

I amazes me that I had to insist to be able to maintain FL350 when I had advised him before that I was reluctant to descend due to weather!

Sorry, but it really does appear to me that, once you pass Austria or Switserland southbound, the quality of ATC goes WAY down! What happened with this ATC instructions from Zageb was only a small and harmless proof of that in my opinion.

I admit that I enjoy and appreciate ATC knowhow in western Europe.

I did learn here that there's no rule or habit that allows me to keep my FL when there is faster traffic behind. I would have thought that at least the preferred method would be to make the fast traffic climb, descend, turn if he wanted to keep his speed or slow down if necessary.

Thanks for your replies,
Sabenaboy

DFC

26th Jul 2006, 11:16

I reckon Sabenaboy's gripe is fair enough. Can't talk for the northern hemisphere but down here the first aircraft able to use a level gets the level. That's in our documents. I would have pushed the other acft down.

Where does it say that the aircraft in front will always be the first aircraft to have reached that level?

The second aircraft could have been at that level before the one in front climbed to it and it allcould have happened several ACCs ago.

A controller makes the decision based on maintaining a safe, orderly and expeditious flow.

-----

I would have thought that at least the preferred method would be to make the fast traffic climb, descend, turn if he wanted to keep his speed or slow down if necessary.

So you will quite happily descend when you are catching up a Citation who is at your level and ahead even if the citation is not going as far as you and is nowhere as fuel critical and the Citation pilot refuses to go down due to weather?

Regards,

DFC

sabenaboy

26th Jul 2006, 11:53

So you will quite happily descend when you are catching up a Citation who is at your level and ahead even if the citation is not going as far as you and is nowhere as fuel critical and the Citation pilot refuses to go down due to weather?
Regards,
DFC

Well I would certainly not expect the Citation to descend into less favourable weather, because I wanted to go faster.

I would expect ATC to tell me to either go down myself, slow down or take vectors off course. If going down would not be a good idea, I'd be glad to accept a slower speed.

I do not know much about A330 performance, but I'm pretty sure that he will not fall out of the sky or burn much more fuel at .78 or .79.

Regards,
Sabenaboy

30W

26th Jul 2006, 12:23

I've had this same problem a couple of times in the same region - and the problem I.M.H.O has been created by previous ACC's.

On my occasions I have heard the aircraft get climb from 330 to 350, or from 350 to 370 with either Rhein or Munich ACC's. Whilst not an immediate problem, I have made mental note that if our routings remain the same (and that is unknown to me at that stage), that there will be a conflict further down the road (1 - 2hrs).

Hey ho, yes, routings the same, and jolly ho I've been descended still a couple of hours away from my destination for him to pass. I've been fortunate in that there has been no weather, but it is still frustrating as I recognised the potentiasl for the problem way back, but it hasn't been an ATC consideration. ATC as a 'system' therefore creates it's own problem.

ATC don't have the tools to be able to predict this sort of medium term conflict, but flight plans can be accessed easily. How about Planners being more proactive in crosschecking and spotting medium term issues, rather than short term ones?? Contentious suggestion I know!!.......

30W

biffo170

26th Jul 2006, 12:56

Perhaps the controllers concerned are aware of the problem down the line but because they are so far from each other at the NOW time, they decide it is safe for them to have the same level so both acft get to cruise (at least for an hour or so) at their favoured level. That way they are doing you a favour now, maybe with the hoping that in an hour one of you two would take a higher level? Often when I have these catch up situations I'll ask each pilot at what time he expects to be able to take a higher level, if it's within a reasonable time frame I'll talk to the next sector and explain the situation. Usually most centres are willing to accept this.........

TopBunk

26th Jul 2006, 16:17

As I fly the 747, the QOTS, and the fastest commercial aircraft by a margin, I have a different view.....get out of my way.

But seriously, if I come up behind slower aircraft (as I did the other day over I guess somewhere near Baku/Afganistan, being given a time constraint over XYZ which meant reducing to about 0.79, it meant we were right back on the slow speed buffet at FL370(?) for about 1.5 hours - a real pain. We did it as the options were limited for all concerned.

I thought however, that in the ANO (and this may only apply to the UK, but I think not) that the Rules of the Air required faster traffic to be given priority, so in this case I think ATC were correct, if vectors could not be given.

AirNoServicesAustralia

26th Jul 2006, 17:05

Now we get the full story. It sounds to me like the controller couldn't descend the A330 at all because of the A320 was at FL350 behind you and probably below the A330. So his only options were to descend you (as he couldn't descend the A330 due to the A320), or use speed control on you and the A330, but considering the weather situation and the possibility of diversions due weather or speed reductions due turbulence he chose the first option. As was said earlier, with CB's around his workload was increased and so he went for vertical, and since you were number one of a sequence of 3 into Dubrovnik he quite rightly wanted you at FL330, followed by No.2 at FL350, then No.3 at FL370. When you advised him that due to CB's you couldn't descend to FL330, he quite rightly used his next best option, that is descend you down to FL350, where there was less chance of a problem with closing due to you both being the same type aircraft.

I know you have the final say as the safety of the aircraft but the controller is responsible for all aircraft under his control and as such has the full picture and made a decision considering the safety of all aircraft, and again to me it is obvious that he made the best and most expeditious decision for all.

rolaaand

26th Jul 2006, 20:28

Sabenaboy-Depends how bad the weather was and how much deviation and turbulence preceding aircraft experienced.If lots of weather deviation was happening then it would be a sound plan to have 3 aircraft in close proximity flying the same route to be vertically seperated. If severe turbulence had been reported then it might also have been a sound plan to suspend RVSM ops and have 2000ft vertical. Difficult to make a judgement call with a very few facts but on this occasion it sounds like the Zagreb controller had decided on a watertight plan in adverse weather conditions just like he/she would have been trained to do,so it's probably unfair to cast aspersions on the ability of Croatian ATC based on the facts that you have stated,cheers,rolaaand.

Lon More

26th Jul 2006, 21:22

Not forgetting also that if you are exiting the UK airspace then I know of no agency other than (rarely) Maastricht that would even consider accepting 2 aircraft on the same route at the same level on headings.
Used to do this all the time Unfortunately not everybody at London understands the difference between parallel headings and parallel tracks. This probably explains the occasional reluctance on the part of Maastricht.
ANSA's and DFC's interpretation is probably the correct one.
30W and others - Western Europe is very much a radar environment. Get further east and you are entering an area where procedural separation (15 minutes long sep.) is the norm, especially when crossing boundaries. Again a case of you not having the complete picture. Sabenaboy's disparaging comments about ATC standards in eastern Europe prove this.
Topbunk said I thought however, that in the ANO (and this may only apply to the UK, but I think not) that the Rules of the Air required faster traffic to be given priority
I don't think so, even Concord(e) never got this. in any case I would think that the requirement to maintain a safe and expeditious flow would overrule this, So if there are, say 5 aircraft at the same level cruising at M 0.81, and one interloper cruising at M 0.78, guess which one will move in the interests of the above rules.

AirNoServicesAustralia

27th Jul 2006, 04:25

I don't knopw why people keep mentioning FL360. I know where I work at least I would have to be in a really bad situation to consider using a non standard level. But then again all of our routes have opposite direction routes crossing them every 100 NM's or so. But considering there was weather around and therefore the possibility of diversions I wouldn't entertain the idea of putting anyone at non-standard FL360, cos that surely will end in tears.

Lon More

27th Jul 2006, 11:47

I wouldn't entertain the idea of putting anyone at non-standard FL360, cos that surely will end in tears.
It's a standard FL in RVSM airspace

Frunobulax

27th Jul 2006, 16:39

Hey, what if there was an OJT trainee on duty?
He might have made a mistake, the instructor might have let him do so so he will never do it again. No delay, no major harm to safety: how can he learn the other way round than by his own errors?

Think of it whenever you get any surprising ATC instruction.

30W

27th Jul 2006, 18:52

30W and others - Western Europe is very much a radar environment. Get further east and you are entering an area where procedural separation (15 minutes long sep.) is the norm, especially when crossing boundaries. Again a case of you not having the complete picture.

Lon More, with respect I think your picture is currently in old 'black and white'. The airspace under discussion has for a long time been a high quality Radar Control Service environment. Zagreb, Belgrade, Sofia etc all have good equipment, and excellent staff. They operate standard radar separation. All their neigbouring ACC's do also - I operate across the airspace regularly.

Going that direction, and further East, I can stay under radar, with normal levels of separation all across, Turkey, down through Iran and all the way down to Oman's southern boundary.

Everywhere within the normal European route structure to places in the Med etc, in this case Zagreb ACC was the one in question, offer the same level of service as yourselves in Maastrict. Only one which spings to mind as not is Casablanca, which does have radar, but operates enhanced radar separation.

Rgds
30W

AirNoServicesAustralia

27th Jul 2006, 20:21

Yes Lon More I do know that FL360 is a standard level in RVSM airspace, but in the RVSM airspace I have worked (Australia and the Middle East) it is a Westbound RVSM level. As I understand it these 3 aircraft were all Eastbound so the standard levels for them would be FL330, FL350 and FL370. You may not have crossing opposite direction routes where you are but where I am we would only use a non standard (or non hemispherical, or non semi circular or however you want to put it) if we were in a real bind, cos the only thing worse than having 2 aircraft at the same level same direction in bad weather would be to have 2 aircraft same level opposite direction in bad weather. So I reiterate that as far as I am concerned, without knowing the airspace and route structure, FL360 would be a very bad call.

kontrolor

27th Jul 2006, 21:26

I admit that I enjoy and appreciate ATC knowhow in western Europe.
...
Sorry, but it really does appear to me that, once you pass Austria or Switserland southbound, the quality of ATC goes WAY down! What happened with this ATC instructions from Zageb was only a small and harmless proof of that in my opinion....
Sabenaboy
well, this is a hit bellow belt my dear flyboy! I work as ATCO in Slovenia (which falls into your "bad ATC countries" definition). Before you entered Croatia, you were in our hands. You obviously haven't tried or seen how it is to work with bad weather all arround and pilots trying to avoid it and us juggling arround to keep everybody separated from both weather and other traffic. I've just come home after a very tough day, where nobody had to descend due another traffic for more than 1000' and you know, how small our airspace is. So your validaton of service after Austria is not fair. How often do you get a radar vector just to get a climbout or to avoid traffic in Austria? From my experience almost never. We do wonders and I get home tired as a dog just by granting almost every wish from the pilots, especially when there is adverse weather in the region. Because I know what it means to you, and why you are doing it.
So I personally as ATCO you bashed so shamefully feel offended by your remark.
Next time you get direct routing (you get it from us in 95% of cases), and when you don't have to descend into bad weather and you get 5 degrees of offtrack just to be able to maintain your level...think of us.
:(

millerman

28th Jul 2006, 23:20

TOPBUNK - As a slight aside, I have in the past told a 747 to descend due to faster traffic behind! And when the slightly confused captain asked for the type and speed of the aircraft - which was a new citation doing M0.91!!! - he was more than happy to descend. He was only 20nm from top of descent though :)
As for the rest of the disparaging remarks from other people - I think you are being very harsh on our eastern european colleagues - you haven't got the full picture with regards to traffic, restricted areas, regulations and weather. The controller made the best decision at the time, and maybe after thinking about it for a while or discussing it on a web forum for a few days he would have done it differently, but he didn't have that luxury at the time.
I don't know of any controller who doesn't try to provide the best service possible at all times and that is why we are a very proud profession;)

sabenaboy

29th Jul 2006, 08:21

Before you entered Croatia, you were in our hands.
:(
Well, I don't think so. That day, as usual, we went southbound via KPT, PITAR and then continued via PUL and SPL. I believe we entered Croatia from the Padova sector on that flight.

I don't recall having come into Slovenia airspace lately. (On our flights from Belgium, we usually pass east or west of Slovenia)
So I have to admit I cannot judge Slovenia ATC and therefore I will have to give you and your colleagues the benefit of the doubt.

I think you are being very harsh on our eastern european colleagues - you haven't got the full picture with regards to traffic, restricted areas, regulations and weather. The controller made the best decision .......

Well, I agree that I did not have the FULL picture, but it appeared to me that the ATCO didn't have a good picture of the full situation (especially weather) either.

Also I have to say that all the other readers of this thread surely can't have a full picture of what happened, since they weren't sitting behind the scope and all the "facts" they know come from what I have written in my posts. Still, being of the proud profession that you truly are, many jump in, defending their Croatian colleague without having “the full picture” themselves. Hey, guys, be realistic, ATCO’s, like pilots, sometimes make small or big mistakes. (I’ll be the first to admit that I sometimes make small mistakes and can only hope never to make a BIG mistake)
My initial post was not about blaming someone and certainly not about me being mad at the ATCO in question. I was simply interested to know if there are rules about who can keep his level when situations like this arise.
I don't know of any controller who doesn't try to provide the best service possible at all times and that is why we are a very proud profession;)
“try” is the keyword in the sentence above. I’m sure that (almost) every atco TRIES to do the best possible job. I could try to be a good doctor, but I would never be a good one without a good training and the proper equipment. It’s still a fact that the selection process, training provided, available equipment, existing procedures, knowledge of English and correct pronunciation, use (or not) of local language, adherence to R/T phraseology etc, sometimes differ greatly between different sectors. (just like in pilot training and airline operations) I used to fly for DHL, Sabena and, since the SN bankruptcy work for a Belgian Charter (Holiday) airline. My knowledge is therefore limited to “greater” Europe and the typical medium-haul holiday destinations outside Europe.

I am not ashamed to say that, of the sectors I have experience with, the best APPEAR to be The British Isles, Germany, Belgium, Holland, Scandinavia, Switzerland, Austria, Maastricht and perhaps one or two I forget to mention. (I’ll give Slovenia the benefit of the doubt :) ) All the rest appears to me to be at least one or several steps lower on the scale. The worst being Cairo ATC, which I even find unworthy of being called “ATC”.

I’m expecting to get flamed for what I just wrote in the last paragraph, but I’m sure that most pilots, coming from the above mentioned countries will tend to agree with what I said.

Perhaps someone could start a poll among pilots to know what they think about ATC in different countries.

Regards,
Sabenaboy

millerman

29th Jul 2006, 09:00

Hi Sabenaboy,
I agree with you that the controller doesn't have the full picture with regards to the weather. Even here in Maastricht our weather display that we see is woefully inadequate and we have to rely on the pilot reports ( they are the ones that actually see it!) all we see is a grey mass with no information on individual cells. However, each pilot responds in a different way, I have seen some pilots go straight through without a word, some avoid the weather by 10 miles or some deviate by 50 miles - all for the same weather at the same level! When this happens we can't second guess what each individual pilot will do so we go for different levels and safety takes precedent over service (as is always the case :) )
I have been working over the last few days with all the CB activity in our airspace and I certainly know I have had to work! With regards to your original question maybe the controller was coming to the end of a busy shift and just went for the easiest solution - we have all been there and done that:ok:

AirNoServicesAustralia

29th Jul 2006, 13:41

Phantom99

30th Jul 2006, 14:20

Used to do this all the time Unfortunately not everybody at London understands the difference between parallel headings and parallel tracks. This probably explains the occasional reluctance on the part of Maastricht.
Out of interest I'm not totally sure what you mean by that? I totally understand the difference between the two but in my sector (S12) no tracks are deemed separated on own navigation...are they the other side of the boundary?
In terms of westbound flights into the LTMA, very happy (S13/14) to accept parallel headings rather than 1000ft deparation, it saves me having to put them on parellel hdgs! :)
Thanks!

biffo170

30th Jul 2006, 15:26

Phanton99, What I think is meant by that, is that two aircraft on the same heading may not be 'tracking parallel'. It is possible that because of the relative aircraft size in a crosswind that the aircraft can be converging even if on the same heading.

BOAC

30th Jul 2006, 16:42

NB ATC: be aware that any heading steered by a 737 'Classic' will be 4-5 degrees less than you think it is (in the UK and Europe anyway) due to incorrect variation being applied. This may make you rethink the 'parallel heading' idea. Reason is complex but 'true'.:)

Phantom99

30th Jul 2006, 16:54

Ok, I see what LonMore means now...

I'm pretty sure nobody trusts reported hdgs 100% accurately though, as one pilot could have rounded to nearest 5 degrees, so the vector lines come in handy to double/triple check :)

kontrolor

30th Jul 2006, 17:59

sabenaboy, tell me what company you are flying for, and I'll tell you what we ATC personell think of conduct from your pilots. That is what you are doing here. Judging. I've heard many rude things on frequency from pilots, but I've never heard of case TWR controller judging a landing over frequency. :rolleyes:

BOAC

30th Jul 2006, 18:43

Phantom - my point was made for ASSIGNED HEADINGS, not 'reported' which I would (hopefully!:) ) assume were accurately flown.

Pipin mali

31st Jul 2006, 02:07

sabenaboy

31st Jul 2006, 05:54

Hi! I am an air traffic controller from Croatia! First I wolud like say that that I dont like underestimating of our job and capabillity of controlers of eastern europe! Hm,sabenaboy your story is pretty uncovincing! You heard for a phrase: Unable to comply??? I think that you have said that,a controller wolud find another solution for you? I would like to have have a green light every time I reach the crossroad,but I dont!!! So think about it!!! And for people that have something against east europe,I can give my personal experience,when I was expelled out of train in Austria from tain Wienna-Ljubljana,without explaination and refundation of money! And we had to wait 7 hours for next! And we were told that there is a problem in Slovenia,but they were laying,cause a train from Slovenia in opposite direction was travellig in regular time! That could not happen in Croatia,if could,our authorities would ensure at least a glass of water for people that are waiting for another train,what havent happened to me!!! Regards!

Hello "Pipin Mali",

IF you really are an ATCO in Croatia, I have to thank you for your post!

I realise very well that, being a non-native speaker, MY knowledge of Shakespeare's language is far from perfect. I also realise that I have more then probably made a few spelling mistakes in my previous posts myself.

But, if your level of English is representative for the level of English spoken by ATCO's in your country, you have clearly demonstrated what I was trying to say about "knowledge of English" in different ATC sectors.

Thanks,
Sabenaboy

Radar

31st Jul 2006, 08:35

sabenaboy,

Been following this thread all week. It's beginning to get very repetitive. You posed a simple question in your original post. "Isn't it very unusual to make traffic descend because the following traffic is catching up?" Straight and simlpe answer: No! Can we move on now before this degenerates into a willy wavin' contest (or willy judging contest based on the last few posts).

sabenaboy

31st Jul 2006, 09:17

You're absolutely right, Radar! I got the answer I was looking for.

I'll stop contributing to this thread, before it degenerates any further.
Thanks for replies!

Regards,
Sabenaboy

FlightDetent

31st Jul 2006, 10:54

"Due to weather we would like to maintain FL370 if possible"
ATC: "roger"
Sire, I was on the frequency with you and well understand the reluctancy to vacate the assigned FL. Be it fuel, first come - first serve, or CBs. All applies. What you did forget to share with readers here, is that apart form the professional and topical infromation over R/T you describe I also heard "Split, isn't it a bit unusual to descend us because of somebody behind?" and similar comments accounting for about 50% of your transmissions. I am sorry to say, thick smartarse sound. I understand that it is not the sound of the transmitted word, but trust me that was the sound perceived. There shall be no disputing about which of these were the controller's input.

I agree that the proficiency of controllers lessens east of Greenwich. So are their resources and training I'd guess. DUS is no LHR. Yet I feel it is foul play to blame our partners infront of radar screen. Each country has its own system well suited for their needs that differ. Aviation is very standardized system but it is still a little more international than ours respective backyards.

I am quite inexperienced, yet I have been given direct to Gatwick LOC from overhead Frankfurt, was allowed to hold at OM for fog to dissolve at FL390, heard tower reply with "thank you" :eek: when having fuel temp hi - shutdown engine on line up 27R. (actually, thank YOU gentlemen!) I do not enjoy frequency change overkill in Moscow and level restrictions, but on the other hand you will always get "avoid CB's at commander's discretion using on-board radar when possible return to track, cleared for approach" DELIGHT.

That was not an nice early morning over Balkans, some systems are not as effective as others, but you were not made crash into anybody, or shot down mistakingly, right? (lighter side up, now). Frankly, I believe that under more evolved and effective ATC flow system you would not be allowed into FL370 at first place. In places where you get a level reserved for somebody else, you need to vacate it sooner or later.

Assure separation and provide safe, orderly, effective and economical flow of traffic. Given the fact that the air mass over FYROM Macedonia (Skopje sectors) was about ISA +16 I see very few things that may have got hurt.

Cheers,
FD.

FlightDetent

31st Jul 2006, 11:36

Since the originator of this thread doesn't want to acknowledge the explanation I gave based on the information he provided I will try again. Based on what he said, the controller had a situation where he had in front an A320 at FL370, behind he had an A330 faster also at FL370, and below and behind he had an A320 at FL350. It seems clear from what was said, he couldn't descend the A330 because of the A320 at FL350. So his best option was to drop the first A320 to ideally FL330 due to the weather and problems with trying to run a tight radar standard same level in bad weather. When advised of the problem with putting the first A320 down to FL330, he went for his best plan B, that being drop the first A320 to the same level as the second A320, ie.FL350 and peg speeds, no big deal with same aircraft type.
Again seems like from all info provided the controller did what he should have done.

:D :D :D

So why was slowing down the 330 from .8x to .78 plan C and not a plan B for the controller? Perhaps because the controller is just like us pilots payed to always keep an extra viable alternative up the sleeve? Just what if then the leading 320 would slow down to .76 (+/- .01 for variations) due turbulence in such a CB filled environment? How would a heavy 330 feel at .75 in turbulence? What if the aircraft decided to avoid a cell with different headings thus coming even closer behind each other. What if there was traffic at 330 10 minutes (80 NM) ahead with no avioding or turbulence report.:ok:

sabenaboy

31st Jul 2006, 13:26

I'll stop contributing to this thread

Sorry, allow me to make one more contribution. ;)

What you did forget to share with readers here, is that apart form the professional and topical infromation over R/T you describe I also heard "Split, isn't it a bit unusual to descend us because of somebody behind?" and similar comments accounting for about 50% of your transmissions. I am sorry to say, thick smartarse sound.

Well, apart from reading back (and executing) ATC-instructions, I can remember that I said:
1."Due to weather we would like to maintain FL370 if possible"
...
2."Roger, descending FL 330, Callsign123, And euh, Zagreb, isn't it a bit unusual to make us descend due to faster traffic behind"
...
3.During my descent "Zagreb, confirm FL 350 is not available as well?"

Probably, you will be able to acknowledge this.

I have been flying for a living now since just over 10 years and I promise you that those sentences are the first and only time I have "argued" (If that's what you would like to call it?) over the frequency with ATC. (I don't think that that is enough to qualify me as a smartarse. )
Since you were there on the freq, you will probably also remember that Zagreb, didn't answer anything to my question about the "unusual" aspect. Not even a simple "Sorry sir, that's the best solution tonight" or something of that kind.

I agree that the proficiency of controllers lessens east of Greenwich.
FD.

Wow, that's even much worse than what I said myself in one of my previous posts! :E
I think it's time that we stop discussing quality of ATC in this thread and get back to doing our job in the cockpit or behind a radar scope.

My weekend is over tomorrow and I'll check out Palma de Mallorca ATC when I get there! (Just kidding :cool: )

Cheers everybody,
Sabenaboy

Pipin mali

31st Jul 2006, 15:33

Hello "Pipin Mali",
IF you really are an ATCO in Croatia, I have to thank you for your post!
I realise very well that, being a non-native speaker, MY knowledge of Shakespeare's language is far from perfect. I also realise that I have more then probably made a few spelling mistakes in my previous posts myself.
But, if your level of English is representative for the level of English spoken by ATCO's in your country, you have clearly demonstrated what I was trying to say about "knowledge of English" in different ATC sectors.
Thanks,
Sabenaboy

You got it,man! I want argue abouth that,cause I really dont watch grammar when i write,and I dont care! Everybody has own opinion,but I dont like generalization! So, if you are afraid of croatian ATCs English, you will have to learn Serbian and than whole world will understand you!!!

Lon More

31st Jul 2006, 15:53

the proficiency of controllers lessens east of Greenwich

There are some fairly cr@ppy ones west of Greenwich too :)

30W

31st Jul 2006, 19:11

Pipin,

For what it's worth, I don't think sabenaboy's comments are representative of the industry. If you read my earlier post, you will see that I believe we get a high level of ATC service from yourselves and others in the region. Don't let Sabenaboys comments get to you...........

dovidjenja
30W

garp

31st Jul 2006, 21:01

The only manner to avoid situations like this is for pilots to pay a visit to the nearest ATC unit and sit down beside the controller, watch the guys at work and ask as many questions as possible. Almost 20 years in the job and I can probably count the number of crews that wanted to spend some quality time in the ops room on one hand. Sad but true.

Frunobulax

31st Jul 2006, 22:47

Well, I used to fly FAM flights or at least tried to sneak into the cockpit on the paid ones.
Never recall crews to get to the ops room though.

In other words: I did my best to learn the other side of the radio. The other side never did. Now I know their limitation, they do not know mine.

Still I hear some pushy comments on the radio, my pilots never do. Sad but true.

BTW does anyone recall some ATC unit that is famous for its arrogant staff?

Pipin mali

11th Aug 2006, 23:00

Np,probably sabenaboy is from B.....,or F.... or some similar aviation problematic country,so I forgive him on his fantasy!!! The best pilots I have ever seen in airspace where I work,are from Hungary (Malev) and no one cannot deny that!!! Those guys are absolutely fabolous!!! And the worst one are from ...... somewhere in west Europe, I will not generalize, but never seen a pilot of west european airliner to land an A320 with 15kts tailwind,but Aeroflot B737 whitout a problem,and I will not talk about T154!!! So,don't get this to close to your hart- this is just a contrary that sabenaboy said!!! And it is stupid to be stupid like he is!!! He is not satisfied with east european ATC,but I think that most pilots are... cause we are giving our whole but ,to make things working properly!!! And over my back passes minimum 200 aircraft during my shift and they all safely arrive on their destinations,so... man get a job like milkman and than you will not have to descent anywhwere!!!

PPRuNe Radar

12th Aug 2006, 00:43

I will not generalize, but never seen a pilot of west european airliner to land an A320 with 15kts tailwind,but Aeroflot B737 whitout a problem,and I will not talk about T154!!!

Is that something to be proud of ??

It will surely depend on runway length and performance calculations. Sometimes it will be safe to do so (regardless of pilot or operator origin), more often than not, than it will not be a very clever course of action.

There are several websites where you can compare accident statistics for operators, nationalities, aircraft types, and locations. Bravado about being able to land downwind ties in with my general overview of aircrew operations in certain parts of the world. But then, that's my opinion. Borne out by statistics.

My opinion of ATC in the same parts of the world is much more positive :ok: