I am quite happy as a ATCO to say its ATC providing pilots with a service, however, what a crutial service it is.

On a slightly different edge, and one thats been here before, is including the 'expect FL*** by ***' I have had far too many experiences to now have to reinforce this to some, but time and again have to clarify its only an 'expect ' level. We need this read back on the tapes, otherwise we are in deep sh!te should a level bust occur. When levels are known by me to be published in the STAR charts, I feel the whole transmission to be a total waste of time, but when they aren't reitterated by me, at least half check what to expect. Its a case of either "why print them" or "why have to reitterate them".

So to all pilots out there, do you expect to be given the restriction eventually and ALWAYS plan descent for them, or are you one of those that will only get there if told to do so at top of descent??????

Loki - because we fly in lots of different ATC sectors we often get 'descend FLxxx' which on query turns out to be 'when ready' or 'at pilot's discretion'. Not everyone is like you and says 'when ready'. This probably makes us wary!

BTW Any chance of the CAP 'guidance'?

5miles- all modern FMCs can (should) be programmed with the published altitude restrictions. There is NO excuse! I agree with you, it is a pain to have to read back 'level 75 before MID' when you and I know it is in the STAR!

I find that 'descend now' doesn't use nearly as much R/T time as responding to the query "Is that descend now, or pilot's discretion, London?"

One thing I've noticed, though. Why do some crews request descent, then not leave the level for several minutes? Seems to be a charter airline peculiarity.

Also, in the recent months of excessive delays, level restrictions, etc etc, I've found flight crews to be tolerant, friendly and uncomplaining.
So to pilots using UK airspace these days, thanks.

:)

Been away for awhile <G>....

Over here, one reason you don't hear to many folks say descend now is because that isn't the proper phraseology. Descend and maintain means descend now... What you will usually hear over here is either descend at pilots discresion or cross XXX at and maintain... Do we sometimes just say descend and maintain when we don't need you to go down right now? Sure, but that was already explained rather well by AF-1.

As to the direct thing... We have been briefed by the companies that they have spent quite a few bits of money investing in flight planning software that looks into the most beneficial route of flight ( unless of course we have a traffic flow management route in effect due to weather ). When we up and give someone direct that then takes them out of the most beneficial wind component, the pilot flying is happy, but then the company is unhappy and sometimes actually makes a call to either us, or an acars to the flight deck when the dispatcher figures out they aren't on the flight planned route and has them get back on it. Thus making the workload even more for someone else a hundred miles away.

regards

Scott, you're right that 'descend now' isn't correct phraseology, but, hey, if it works...

Out of interest, do you ever have problems with the term 'maintain'? If you clear an aircraft to a level without using that word, what will he do when he gets there?

In the UK, maintain is generally used to advise a pilot not to expect continuous climb, and caution therefore is used when talking to American pilots.

Hope things are sweet in Tx!:)

5milesbaby. Interesting question. Ay my home base the arrivals all have several descent restrictions but I have never once had to comply with them all. In fact I have never seen most of them imposed. There is usually only one of the restrictions which applies and from local knowlage thats what I "plan"my descent on. Several of the arrivals have very "Draggy" restrictions which force an early descent but are only enforced in busy periods or when there is a full moon or something. Some have "Secret" restrictions which force a screaming jeesus descent to satisfy if not planned on. Confused? You should be.
While we are on the subject of wasted atc transmission time ,why do ATC insist on all these (unpublished and secret) "Twenty before Trents" and "Ten before Monty" things when the FIR is festooned with waypoints that nobody EVER uses?
Question-"Is that at our discretion?"
Answer-"Affirm" or "Negative" That wasn't really too difficult or long winded was it?

The maintain part is just another thing in our verbage in our ATC bible... <shrug> I understand that if all is done right, you are going to maintain that altitude <G>...

regards

Homer, I can answer one of your questions. FL200 lvl 10nm b4 Monty is the Standing Agreement between London Sector 5 (Brecon) and Manchester West Sector. Manchester West have to then get you below FL195 BY Monty, otherwise you enter another Sectors airspace (S29). It keeps everyone happy the way its done, and as the STAR chart starts at Monty, the restriction to expect before it aint written on. However, in my mind and many others, it should be for the whole descent to keep everyone in the picture.

If people feel having them all on the plates is useful, how about getting together to get them changed??? There must be a division in NATS that could help out, although new centre = new division = new name !!!!!!!!

Come on - someone must have the ATC bible in the attic! What DOES 'descend' mean in the UK? Can it be expanded to 'now'/'when ready'/'pilots' discretion'/etc within the CAP terminology?

Knowing this will help us IN THE UK at least - we will still have to juggle the foreign 'balls' though, but maybe we can take a bit of steam out of the kettle here?

Any gurus know from where Jepps and Thales get their info for airfield plates?

Just dusted off my very old Mats Part 1. It`s not very forthcoming.

OK - how about the ATC PPruners spread the word?

How about we trial, say ?a couple of months?, using the differentiators 'now' and 'when ready' - with any 'gates' you want us to achieve - for descent clearances in the UK? (Hoping your managers don't throw a 'wobbly' of course!).

Let's have a 'debrief' on how it went, here, then?

Over.

I'm afraid that I am struggling to work out what it is about the word "Descend" that people don't understand. It is an instruction, a command even. It doesn't mean "when you feel like it" or "when your on board computer feels like it" or when you've finished your coffee and the crossword. It means "DO IT". NOW would be nice. After all, if I say "turn left heading 290, closing from the left report established", pilots don't ask if they should do it now or at their discretion. Why should "Descend" be any different?

Rightly or wrongly I teach trainee controllers that when they instruct an aircraft to descend, it will, plus or minus the "wake-up-was-that-for-us" scenario and the inevitable short delay actually getting the thing to come down. But to all intents and purposes read "immediately".

There is nothing (that's ZERO) in the MATS Pt1 about "Descend when ready" or any equivalent. Descend IMMEDIATELY (my caps) is to be used only to resolve an urgent situation. The only bit that looks remotely useful is "Descend to reach (level) at/by (time/significant point).

For the curious or bored the MATS can be read at

http://www.caa.co.uk/docs/33/CAP493__Part1.pdf

then go to Section E (Attach) Page 3 and look for the Climbing & Descending bit.

Controllers do appreciate the economics of commercial aircraft operation and try to take that into account BUT there has to be a trade off with other requirements such as other traffic, sequencing, standing agreements with other units ad nauseum. With the best will in the world your ideal descent profile is going to be bent a bit. Don't add to it by causing controllers to mutter "Of course I mean bloody now!"

From this thread, it seems that many ATCOs are uncertain of the method of navigating, vertically, in modern (FMS-equipped) aircraft. In a couple of weeks' time, I would be willing to start an 'FMS Q and A' thread, and to do my best to answer any queries ATCOs have about these matters. Would this be a help? Are there any other experienced jet pilots out there willing to pitch in with answers, too? (I'm currently on Boeings - and mahogany bombers, so not a sharp as once was - but with previous 'bus technology experience. Is there a currect 'bus driver who might give that persepective?)

Or am I miles off?

Well, Bern has made his point fairly clearly! All we flight crew need to do now is to clarify the rest of the world's R/T procedures outside Bern's sector. I shall now TRY to remember not to ask 'is that when.............." - in the UK.

Next 'Q': Is 500'/min an acceptable minimun rate if we are not actually ready for descent?

NS - happy to help (Boeing again) if you need it.

Sorry to drag you all back to the direct thing but Scott's comments rang another bell. He's not the only one to get in trouble for offering direct routeings - some of us actually have direct (written) instructions FORBIDDING us from offering them (apparrently, as Scott said, at the airlines' request) and risk getting into all kinds of smelly stuff for doing the sensible thing and making all our lives' easier. Funny , I thought ATC was all about providing a service!!!:confused:

5milesbaby
You've actually raised another point that while (briefly) blip driving at LATCC didn't quite get resolved. "xxx123 Descend FL70 to be level 10 miles before DAYNE/TNT etc."
Now......two schools of thought here
1. Descend at standard expected rate (1500 fpm) which could level out well before the 10 mile minimum, ie level out early
2.Descend at a computed rate to achieve level exactly at 10 miles before which could be a descent rate of anything from 500 - 2500 fpm.
There could be potential conflicts with either of these.

Another option which was dismissed was achieving a 1500 fpm descent to achieve level exactly 10 miles before, which meant delaying the start of descent.

We were told categorically that "Descend" meant now. "At your discretion" whenever, there wasn't anything in between. Why should there be? You don't qualify "Turn" "Climb" so why "Descend"?

Hi Jane,

See me earlier reply.

'Turn' - by the very nature of vectoring, is given at an appropriate time, and does not delay our progress (unless it's one of those French 60degree jobbies to allow Air France to carry on without changing course).

'Climb' - well, we're not going to say no! You will know that our engines are most efficient at altitude, so we always want to be as high as we can (weight plays a small part here, as may very strong winds).

'Descend' - equivalent to 'get there later and burn more fuel'. In the circumstances you describe, we'll either use Vertical Speed mode to achieve 500fpm until on the desired profile to just make the restriction,followed by idle power descent, or use VNAV in 'Capture' mode, which will give a 1000fpm descent until on the profile, then ide power descent, or use level change/open descent to give the least efficient idle power descent to the cleared level. Most pilots will not do this last one. 1500fpm is not stated anywhere as a standard rate of descent.

By forcing a/c to leave a level earlier than they want, I understand that the initial rate of descent won't be that high. However, at least they are going down. Being told to leave early means that normally something is in the way, or the one in front is descending and we want you in similar levels to speed effectively. Expediting an a/c already in the descent gives a more immediate resolution than one told 'start descent now, expedite' due to the delay in initial downward movement. In the ideal world, (like the sims) getting an a/c to leave and giving the restriction, I would like to see the rate of descent adjusted to give a constant rate of descent to hit the restriction, but I know in the real world this'll never happen.

I've started on a couple of my sectors now to give intermediate restrictions to ensure that an a/c is at the level I want it to be at to able separation in the awkward corners. It works well and creates none of the problems in this thread.

Remember the MATS Part 1 is NOT the sole document which ATC have to abide by. We also have the AIP and the CAP 413. Seems black and white to me from those other documents what to expect. But then I always was a simpleton and liked the easy way out in life ;)

Do we really need to reinvent the wheel ???

Don't know if it was as a result of this thread, but inbound this AM on a Willo3B to LGW, and a very clear 'Descend Now' from the controller. Great!

It may not be 'kosher', but by 'eck, it is clear! Is there really a problem with this?

"Pilots are expected to comply with ATC Instructions as soon as they are issued. However, when a climb/descent is left to the discretion of the pilot, the words 'when ready' shall be used; in these circumstances the pilot will report 'leaving' his present level. "

I think, PPR, most of us appreciate this, but as we have tried to explain, this is an international forum, we fly internationally, so it is not just a UK thing. Not normally a problem for UK pilots in UK airspace as we generally know and are ready for all the arcane descent restrictions, but maybe for visting crews.......?

BOAC

Just out of curiousity, what is ambiguous about descend level XXX? Or in our case, descend and maintain XXX. If you don't hear pilots discression it means only one thing and is less verbage..

regards

Don't have the book at hand to check but I think the ICAO 'pilots discretion' phrase is exactly the same as the UK one.

So, as Scott alludes, it should be clear that an instruction without either 'when ready' in most of the world, or 'pilots discretion' in the USA means that we want you to do it now.

I don't think we should have to spoon feed pilots in these busy times, it wastes our time and yours. And time is becoming a rare commodity both on the flight deck and in the ATC facility.

I tried to explain a while back - in Europe, (my area) 'Descend xxx', when queried, is often found to be 'at pilot's discretion'; I am reluctant to point at any particular countries, but there are a few where this is more often than not the case when a 'early' descent clearance is given for no APPARENT reason, and nearly always for some inter-area hand-over agreement. This is NOT a 'pop' at ATC, but an attempt, as I judge from other posts, to reduce R/T loading (OK - pilot generated!), and does NOT refer to UK ATC. The only criticism there is a systemic one where the descent 'restrictions' are sometimes 'known' only to the controller.

I think from all the posts, NorthernSky's (6/8) sums it up best:

"As pilots, we want to stay at cruise altitude and descend with the ideal profile.

All of the above debate seems to spring from one annoyance: If ATC give us a descent instruction, in the form 'Descend FL330', we reply, 'Roger descend FL330, is that pilot's discretion?, and ATC say 'Affirm, that's when ready'... then we're not being provided the SERVICE that we should be, in the first place.

In a nutshell, the controller should ALWAYS specify 'when ready' when it applies. Not to do so costs us money.

Because they don't, we ask. If they did, we wouldn't ask. "

It is because there are quite a few who do not say 'when ready' when it is relevant. I have NO issue with your NEEDING me to descend. I will. Maybe it is a training thing in those areas where it happens more? It appears that ALL ATC people on this thread DO say 'when ready' where it can be given. Good. The problem lies with those who don't.

It SHOULD be abundantly clear to all pilots reading this thread that 'DESCEND XXX' means now. That is what I have always assumed it to mean. It is just that after a few hundred descents where it was not necessary THEN, we become a bit inquisitive!

Can I also take it from the lack of comment that 500fpm is OK with ATC for an 'early' descent (unless other rates specified)?

The original thread post raised another issue - that of pilot awareness of/ and interaction with/ FMC programmes. There is an obvious gap there in the way the FMC works v the ATC 'picture' of what we will do, and we need to close that gap.

Fair points on 'When ready' BOAC. And let's hope that they are taken on board and the word spread so that the service improves for all concerned.

On the other hand, I have had some (very very small %) pilots query the 'when ready' part with 'do you want us to descend now ??'. My normal reply is something like 'Negative, the clue was when ready'. Must try and curb that kind of reply ;)

The 500fpm is laid down as the minimum in the national document in the UK (AIP) so I don't think anyone in ATC can argue they expect otherwise. It actually raises an interesting point, which has appeared in a few threads. And that is that quite often we see ATC people claiming they expect to see different things from the standards notified in the relevant ATC and pilot documentation. For example people saying they expect to see a standard rate of 1500fpm (whose standard ?? it's not a published one). Or people saying that they are aware that a new level clearance cancels a previous restriction, but they expect the pilot still to do it. If they are basing separation on things they expect to see, rather than on the things which the regulations and procedures mandate, then I fear their technique is setting them up for a fall one day. There is only one way to be sure and that is to know what the procedures say, and if you require something different then positively specify it.

I agree wholeheartedly about the FMC gap. It is something I was looking at a while back but the project was overtaken by events. Perhaps it is well worth dusting off and resurrecting again.

:(
Excuse me if anybody said anything similar to what I am about to say, but I couldn't stomach much more than a page and a bit of this. I started reading this thread with great interest, but I was sadden by some of the comments I've read from both sides.
As a pilot, I have great respect for ATC.
Funny old world...
I've learnt a bit today.
:(

Hi BOAC;

I understand your frustration. But I think that most of us do give when ready <G>, when we can and it is minority who do not.

As to the descent. If I give you lower. I consider 500 fpm a float down. When I give a descent, I and many of us expect an aircraft to come down like it was the crews decision to come down <G>.

If I am getting you down, it is either for traffic, to miss some other airspace, procedural, or just trying to get you down where a 250 knot speed restriction means something <G>.

regards

Not really frustration, Scott, consider it 'eagerness' to get both sides of the microphone understanding each other's problems. We had a fair bit of success a while back with the 'LGW arrivals' thread in learning such (not so much with 'LGW departures') and I hope this will do the same with 'descents'. In conversation in the pub last night it seems there may be more queries from UK pilots on US descent profiles which I hope they will raise here (my horizons are short-haul Europe only).

PPR (3 above) highlights discrepancies on expected descent profiles which should be explored too?

Just my tuppenceworth:
"Descend" means NOW;
"Descend when ready" means just that!

It is also worth reiterating an early point which got swallowed up:

If you ask for descent and are given it, then DESCEND. Don't sit there for another 10 miles waiting for the FMS to reach TOD and then wander down. In many of the busy sectors such as Clacton, your request for descent will mean that the ATCO will make a plan for you and the other aircraft based upon you descending when you ask for it, maybe ducking under another aircraft which was borderline for descent before you but now will be subject to your descent. If you mean "We would like descent clearance to start down in 15 miles" then make that clear. You are pilots, not computer operators, after all!! Fly the aircraft, not the computer.

With regard to the "Can we descend at 500 FPM if you give us early descent until we reach the profile" question: Well the minimum ROC/ROD in the UK AIP is 500 FPM so of course the answer is YES. Bear in mind, however, that if you are asked to descend early it is probably because we want you down so that we can also start descending other aircraft who need to be at the same level at the same point as you. If you all did it on the ideal profile then you would all reach the same point at the same time at the same level, and this is generally considered to be a BAD idea in ATC circles! Look at it another way: If you are given descent early, it is likely that you are being put ahead of other traffic, so it's GOOD thing!

why not come and see!!
 

Hardly ever see pilots. The fam flight scheme seems to be dead for now. Borrow a minibus and pop down to Swanwick, there are a few real operational controllers on duty most days, aswell as 753 support and management staff. Speaking for myself you would be very welcome.

Hoover Pilot, I think you have it by George (sorry George). Here in sunny Scotland we sometimes have the capability for short routings, good constant climb and descent and, dare I say it, some chat but listen to how the freq is. AIP does say 500ft/m but if we are quiet, ask and you may help us figure out where your top of descent point is but be aware, we deal with multitypes. If the freq is busy though, do us a favour and listen out and act. We are, in my view, working about as well as we can in the present circumstances and thats good enough for me!

Just one grumble, seen notice of no jumpseats unless Company employees or Family unless written auth secured from senior company source. If we do not get to meet, learn, watch and understand the great toys you fly in. how can we help. No controller ever tried to hammer a captain to death but a Fedex employee managed it!!!!!!!!!!!:confused:

BOAC;

Fair enough <G>... Just got done teaching a pilot class today. Rather fun too. Great class with a wide range of students. Some 100 hour newbies, some multi hour with fresh instrument ratings. Some who are instructors and one who works at SimuFlite and teaches the bigger corporate stuff. The one really fun one was a check airman for a B777 for American. Wish that all of my classes had that much diversity... Really wish that we would see more part 135 and part 121 crews here...

Full day with a half of day of classroom, then half a day on the controlroom floor and in the simulator letting all the pilots take there chance with a headset and try to pry the aircraft apart. Lots of fun <G>...

regards

ANY ATC GUYS HELP!!
 

I just wanted to hear a really straight and easy answer from an ATC guy or girl! May sound like a really silly question! If I am told to

"descend FL200 level 45 miles before Bovvingdon"

Does this mean:

a) Start descent NOW and there is a level restriction to be met so adjust rate of descent accordingly. But actuall strt descent now to avacate that level. or.......

b) Descend when I am ready to meet that level restriction. Eg maybe 5 mins or so!

Hope this can be answered straight - just ATC guys please as I'm really not interested in a hundred pilots own "opinions"!!

Cheers!;)

Flymeboy, as answered in your other thread, its a), descend NOW. If it was at your descretion, you would have been told 'descend when ready FL200'. The level restriction is given as it has to be, and then fully complied with for noise abaitment (big bang) procedures. It doesn't mean level off exactly 45nm b4 BNN (although thats fine), but you must be level by 45nm b4 BNN.

"Scandis at nemos, FL200, 300 indicated for straight in 23"

As I say, it is a while since I went to GVA (sadly!) and I'm not sure where Nemos is as we don't go that way. It could be that they can keep a higher rate of descent longer than BA can?

"I've also on several occasions had BA RJs refuse to turn over the Jura until out of FL80"

Again, rusty on 23 SIDS, but there is a restriction (FL70+ at PAS before setting course, from memory?) Maybe this is the problem? Perhaps the RJs could help?

BOAC,

Ref the Scandis - simply a comment that they always arrive very hot and very high - I actually meant to say Vadar - which is around 35nm final for 23 (only used for arrivals from Zurich direction) but always seem to get it down. Of course, we won't bring "stabilised approach" into it!!!:eek:

Ref: the SIDS, you're absolutely correct, "Right turn after passing PAS but not before 7000ft QNH to intercept....." pretty much the same off 05 - the thing is that again, the only company that regularly refuses to turn before 80 is BA (RJ's only, in my experience). It's not really a complaint, more a comment on an apparrent difference in SOPs.

Thanks again for the replies - you really should try to get back to this part of the world now and agin - the Guinness is not bad at all !!:D :

Dear Colleagues,
I would have thought that "descend now" or "descend at pilot's discretion" would be less ambiguous than "descend". Given the latter instruction in UK airspace, I always query it if I (or aircraft) do not wish to descend straight away. Most Continental ATC centres however do mean descend now when they say descend, so I don't even bother asking.
In my experience a few pilots I have flown with have a poor attitude to ATC and treat them as subordinates. A good example is weather avoidance, where these guys will Tell ATC they are going right 10 degrees" rather than asking or even offering a choice of turn as I always do if I can.
UK ATC are the best in the world in my opinion, nobody else can shift as many aircraft through such crowded airspace.
Keep up the good work guys,
ATB, PTC

Haven't had much of a chance to look in lately (all these tours :( ).

A few observations:

As far as I'm concerned, 'Descend' means 'Now' unless stated otherwise. So I won't be querying it automatically (in the same way that I don't habitually ask if standard speeds apply, see earlier thread!).

However, if it is a route that I am very familiar with, and experience suggests that the clearance is always "When Ready" then I will query it unless (a) Controller workload is obviously high or (b) I'm planning on descend pretty soon anyway.

Almost invariably, when I've asked, the response has been "When ready".

Thinking about it, I guess the quickest way to query is to modify the readback.

Instead of saying:

"Descend FL XX, - is that now or at our discretion?"

or just "Descend FL XX" and wondering,

How about "Descend now FL XX"

That way it only adds one short word to the readback. In effect the crew would be saying "We think you mean now, and are acting on that basis, if you don't then let us know."

The controller can ignore the extra word if workload does not permit, but at the same time it is a small prompt if the controller intended, but neglected for whatever reason, to say "When Ready".


As far as RODs, then I would try and use as low a rate of descent as possible, i.e. 500 fpm, any time I'm being forced below the ideal profile. However, airmanship suggests that there is a reason you have asked for the descent. So, in the absence of any qualifiers like "Good rate through FL XX" or "Expedite through FL XX" I use a reasonable rate for the first 1,000 feet and then slacken it off.



On the GVA SIDs, I'm not aware of any reason to refuse to turn once that 7,000 feet condition is met. However, when we used to fly the noise profile reaching 7,000 by PAS wasn't really a problem (since V2+10 to something like 4,700' ???) but now that we accelerate at 1,000 AGL then you seem to arrive at PAS below 7,000' and are therefore constrained. (I'm no performance guru, thats just the way it seems to work out).

CPB