They don't do it like that at all. Perhaps a naive attempt to 'prove' that Oz controllers are useless... Many HK procedures were developed by Ozzies who went there... As are many procedures in Dubai and many other busy international airports... Time is a constant. 420Kts G/S (7 miles a minute) at 100NM and 5NM spacing is close to 45 seconds, between aircraft, if they fly the exact same profile they will land close to 45 seconds apart and at 150KTs G/S crossing the fence that puts them only 1.8NM apart; which even in HK is too tight! And certainly wouldn't want a 'chain' of aircraft doing that.

Blockla, you are full of it, I flew in/out of HK for over 4 years, how bout you ?
We regularly landed 5 nm behind a heavy ( sometimes just over 3 behind a medium ), think about it, we were at 1500'/5nm/GS 2-2 1/2 miles a minute when the heavy touched down, not exactly ground breaking death defying stuff, but please carry on in your little dream world.

Nautilus, is was not a perfect system and of course not everyone can hold 250IAS to 15nm, I am not that stupid. There was vectoring, speed reductions etc but the cold hard facts are they handled nearly double the movements of PH with their own unique problems like terrain, weather, multiple different nationalities and multiple airspace restrictions very close to HK.
I am not saying Aus ATCs are useless , I am saying the current system was great 15 years ago but it is a joke now ( just like the whole airport ) and it will get markedly worse in coming years, something needs to be done other than saying " we've reached capacity ".

Hi Hong Kong Phooey. I think it is you that is full of it. For some basic sequencing facts...... Two aircraft 10 miles apart out on the cruise in the mid 300s flight level wise, if descending from say 100-110nm with a slow down to 250 knots 10-13000 feet on the arrival will see you need a 20 knot indicated diffference from the time they transition to the indicated speeds as the guy in front willl be around 2000ft below and for every 2000ft, you need 10 knots indicated of difference just to match the ground speeds plus the extra 10 knots to account for the ground speed slow down as they approach the star constraint of 250 knots and even then you willl physically have to pull the back aircraft to 250 knots about 15nm from the height/speed constraint point. That is to just keep to 10 miles. Now, at about 60 to touch down, with matched ground speeds to have 5nm at touch down, you need 10.2-10.4nm between the aircraft if you are going to use 230 knots at about 30, 210 at about 15 then allow (instruct) them to slow to the same speed on final. We do this day in and day out and while Hong kong is not somewhere I have worked, I am assuming the laws of physics work the same there. Interestinglly I have flown in there up the front and there are some seriously track mile chewing arrivals and the ATC use lots of short cuts on them to secuence.

So from the above, If you have a beautiful line of aircraft out in the cruise all exactly 10 miles apart to just keep that during the descent, first one comes down at 320, 300, 280, 260 and everyone gets slowed to 250 at the arrival point, 15, 30 and 45 miles away from it all in a big consateena. Throw a fifth aircraft into that and we have holding/vectoring. Four aircraft five miles apart in the cruise is two too many and will require some air traffic control to be inflicted. For example, the same scenario I used above, for each additional 10 knots of indicated difference, you will gain about a mile. To dumb it down, front guy at 310 knots, second guy at 290 knots keeps your gap, if they are 7 miles apart, you need an additional 30 knots to get your 10 so the back guy comes down at 260 knots. Throw another 30 into that and now we have serious delays. If you can force the aircraft to transition onto indicated (ie descend early) at about 140 miles, 30 knots will give you 10 miles from a dead heat (ie 310v280). This is all pure speed control, hands off ATC. I personally prefer to make you all go flat out, get down fast and stick you into a holding pattern where I can drive the speeds and the distances to actuallly make you get to where you need to be when we mant you as opposed to some lax interpretation of it.

edited to add, the above is pure speed control to keep SPACING as opposed to speed control to achieve a cross point@time scenario.

Hazard Alerts out again for traffic holding today in Perth in severe CAVOK....

Not to sure how they're going to double capacity by 2020 with no infrastructure.

It shouldn't be too long before the rogues are revealed. If there are no rogues, then the Metron arrival rate needs to be lowered!

It would also help greatly if the Metron Perth arrival slots were coordinated with the departure slots; no point in being assigned an outport COBT for the return to Perth that you're never going to achieve because you copped a 20 minute departure delay from Perth on the outbound leg...

Fooey, you're going a bit hard on the ATCOs. Failed physics, did you? ;)

Official announcement last night at West Angeles. Aircraft arrived on schedule," We are loading you immediately, but we will be sitting on the ground for 45 minutes due to our late arrival slot". Immediate loading probably down to some intermittent heavy weather in the area, giving flexibility to depart earlier if deemed necessary?

HFK - to summarise, if you were 5nm behind a heavy when it touched down (which I am happy to believe), you weren't 5nm behind it at top of descent.

From your example, 5nm behind at 2.5 nm/min is two minutes between arrivals. 2 min spacing at cruise, say 7 nm/min is 14nm at top of descent. Please bear in mind arrival sequence distance has nothing to do with ATC rules, procedures, or abilities. It is down to how long you take from landing clearance to clear of runway.

Capn Bloggs - unfortunately, as far was I know, we never go back over bad arrival gaggles to see what went wrong. This and the fact we reward the rouges I think is a major failing on our part.

If METRON gave you unachievable times it would be pretty useless, and its from 'merika where they have real traffic so it can't be :)

ETA
That should be treated as an 'incident' and investigated.

Surely we should adopt the rest of the world procedures and apply compliance on late (get a new slot) as well as early..

Don't know why I'm bothering, but after 21 years of ATC mostly in Arrivals and Approach environments I do know a few things about spacing aircraft. I have been in the HK ATC centre and watched the controllers do their thing, how about you?

Did you even comprehend what I wrote I know I'm just a dumb controller, but ahem... you have clearly and comprehensively demonstrated your blinkered view of the world... Perhaps you may like to retract the "Full of it" remark when you actually understand it... But that is probably naive of me! Perhaps you can quote some more "science" at me...

Exactly what I actually said, just in a different way! thanks, NB :ok:

I hope that Metron is just having some teething problems, because the enroute and arrivals guys are hating it at the moment.

I think Bloggs is onto something as well regarding decel rates. Everyone's playing by different rules when we say "adjust speed to...". It doesn't help with a million different a/c types in the mix either.

As an example, we see the scenario every day where the 146 comes in, meeting his/her time and the groundspeed is almost a constant in the cruise as it is in descent. Qfa and Voz come hurtling in as number 2, at a higher altitude and overtake the 146, relying on dropping the anchors on descent. Problem is, they cant get down cos they're now overtaking and need vectors to get back behind/continue descent.

"But we're meeting our time". Not if I can't get you down, you're not. Maybe we need to get more proactive and make you go down earlier, but then that throws out all of your profiles, especially without notice. I'm not blaming the pilots at all, you're doing exactly as you were told. Most of the time, anyway :ok:

I hope so too, because

just doesn't make sense when everybody's got a COB time!

Sounds like the RTA's should be on fixes before descent then, doesn't it. You do realise that even something as small as the visual star vs the ILS star can change the fix crossing time by over a minute, and a change in runway can affect the fix crossing time by 3 minutes, don't you? I have noticed the RTA's are now getting sent out a lot earlier, but it doesn't help all that much not receiving a star until inside 60nm of the top of descent.

Into PER the other night, bit of a sequencing nightmare, got given a direct to haige, then a vector, then a slowdown, then a speed up, then got asked if we could take a visual? Lotsa balls being juggled no doubt, but I'm starting to wonder......:oh:

"but it doesn't help all that much not receiving a star until inside 60nm of the top of descent. "

Seriously? Many places in the real world you are not locked onto an arrival until 60 to touch down let alone top of descent. You do realise there is more than one plane in the sky right?

Plazbot,

Leaving the star that late only gives you 6 minutes in the cruise to adjust your speed, which will comfortably only give you about +/- 30 seconds. This then leads to descent speeds and profiles which are wildly different from the standard un-impeded profile that would normally be flown, so ATC won't be able to predict what each aircraft is going to do to try to satisfy the fix crossing time. After finally satisfying that requirement at V-min+companyrequirement and the speed brake out, once past the fix speed restrictions are quite often lifted and track shortening is given to help the flow past the fix.

I am not sure that I understand your point. Do you mean the time required by ATC will change?

For a Julim 5A Star, the feeder fix is for Julim whether it is for runway 21 or 03. If the aircraft in the stream are seperated by two minutes then that is constant. As Bloggs pointed out the decel rates are then the issue and what happens inside 15nm.

I have lost count of the times I have been slowed after the feeder fix and then arrive at Woora with nothing between me and the threshold, that is 15nm space infront.

Icarus,

No, the point is the ATC required fix time does not change, but the aircraft's estimate of crossing the fix does - eg when it's all crosswind and the runway changes from 21 to 03, suddenly your profile through julim changes from about 10,500 to 19,000 feet - descent point moves about 25nm downtrack, you are at much higher TAS for much longer, so your estimate moves forward by up to 3 minutes. Now you and everyone else have to slow down to still meet the arbitrary julim requirement even though everyone is in the same boat and the spacing is still the same.

Granted that could a problem if are given a 03 Instrument STAR from the North when you were expecting 21 but your speed will already be set because you would have got a Feeder Fix time well before then. So for 21, when you get the STAR is virtually irrelevant. The routing to the runway is the same and you will have set the speed to make your FF time well before.

As for late runway changes, I don't recall any major dramas or panic about feeder fix compliance; either you can or you can't, simple as that. Not your fault. ATC just manage with vectors until everything settles down.

That may be so but when you don't know the arrival runway until you get the ATIS at 200 to run eg 21 or 03, managing a Feeder Fix time when the worst case (opposite runway/30 extra track miles to that expected) will result in a much quicker TAS through the fix/suddenly early, with little speed potential to correct at that late stage (can't slow down a lot up high).

Okay, thanks Bloggs, I see what you thought he meant now.:rolleyes:

Surely we are also mixing two different systems here. If I have a published slot time to land in PH then that is my slot. I still get Julim fix times which do not in any way relate to that landing slot time. This means the system is already broken and flow and approach are trying to play catch up. It seems to me that even if most aircraft depart at COBT ATC still only really play the game of dealing with what they have got inbound and sequencing as they go. I can see why that would be the case and I am not criticising the controllers, just the system they are given to use. Then expecting us to carry 25-30 minutes traffic holding after delaying a departure by twenty minutes makes me wonder.:hmm:

Exactly. I took a thirty minute delay from PH with a seven minute delay from the destination. Broken by default, there is no way that it could work.

Icarus, Metron (or CTMS before it) is designed to spread out the arrivals so the rate remains manageable, nothing more. Feeder Fix times then contorl the actual sequence to the runway. I thought that was obvious.

Are you implying we just ditch one or the other? If you think you can hit your "published slot time" to the +/- 30 seconds you're better than me. What about if you get held up departing an outport due to traffic? You just arrive 5 minutes late and land in formation with someone at their "landing slot time"?

Of course ATC has to fiddle/massage/delay/speed up aircraft by issuing feeder-fix times after everybody's in the air.

Icarus, as seems to be usual these days, the ability of those responsible to swallow a sales pitch is better than their ability to deliver.

From a controller perspective anything other than the "natural" sequence or as you said "sequencing as we go" is the only sane way to handle a sequence. Anything else rapidly deteriorates into a dangerous farce.

The "first come first served" vs METRON/CTMS order is an ongoing debate. Sequencing as they come is easier for ATC (which means safer and less messing a/c about), but gives companies no incentive to follow METRON, and in fact punishes those that do. Ph flows do seem to "deprioritise" early a/c, but it can make life interesting on arrivals.

Possibly you were being sequenced behind a 24 landing?

No, I did lookout for that one and no departures off 21 whilst we were inbound from Woora either.

TODAY: 50 minutes holding required during the middle of the day and also early evening as per NOTAM.

So a calculated slot and COBT AND 50 minutes holding required. This is having a bet both ways surely? If everyone is complying with their allocated time why would we need 50 minutes? If someone is not complying then let them hold for 50 minutes, no fuel, well off to the alternate it is then.

Is today a sign of what will happen come winter with all approaches IMC and full STAR flown. If so I am not looking forward to that.

Now you are being dumb on purpose. There is enough slack in the system to allow for last minute changes, there has to be to allow for departures.

It appears they aren't. The reports I've just seen indicate that there are many non-conformers. It was stated at RAPAC last week that Perth had a non-compliance rate of 25%, Sydney 7%. The extra holding at Perth is a result of the non-compliance.

No, I was simply pointing out that you cannot provide a decent landing sequence relying solely on landing slots; your words "If I have a published slot time to land in PH then that is my slot." I cannot guarantee achieving my touchdown time within 5 minutes, let alone a few seconds needed to get a tight sequence, and nor can you. You said "mixing two systems" and I said we must have the two systems: the axe-chop rough COBT at the takeoff end and the Feeder-Fix to-the-10-seconds (hopefully) at the landing end.

Icarus2001 - I can see only two possibilities. Either there is other traffic that you are not aware of, or PH ATC are waging an extended campaign of malicious unnecessary speed reduction! Tinfoil hat or occam's razor?

I totally agree with the rest though. Ground delays and 50 minutes holding is not having a bet both ways it's extracting the urine. There are three problems though;

1. What to do with aircraft that are late? If you miss your slot by five mintes, and the next available slot is over two hours later (not uncommon) do we hold you for two hours, or fit you in and delay the next two hours worth of arrivals by one slot?

2. The current procedures only allow early aircraft to be "de-prioritised" by the published holding time, which may well be less than the ground delay given.

3. Worst, and I've actually had this happen.
- Aircraft gets 20 minutes of holding.
- Aircraft tells me, as per traffic notam, is only carrying 15 minutes holding.
- Flow won't bring aircraft forward in sequence unless declaring fuel emergency.
- Aircraft declines to declare emergency because is carrying published holding fuel.
- Ask aircraft for alternate, advises not holding one.
- Stalemate.

Nautilus Blue,

Could you please explain what the aircraft has done wrong in your scenario:
Edit: assuming of course that COBT times if applicable were complied with

Sorry, should of said, aircraft was early for its PTL (this was pre METRON). Even if it wasn't, remember the notam traffic holding time is NOT a maximum, it's an estimate.

Nautilus,

So what would the amount of holding fuel you think aircraft should hold when planning to land in Perth? Personally, I wouldn't depart with less than trip fuel plus holding to PTL, plus NOTAMed holding time, plus Weather holding/alternate as appropriate, plus variable reserve. But you seem to be implying that the minimum requirement isn't enough.

DD, I guess what i mean is the notamed traffic delay is a forecast. Many crews seem to be under the impression it's a guaranted maximum. It's counter intuitive, but ATC has no control over how much holding is required on the day.

PS, if you need "holding to PTL" does that mean you're leaving earlier than you should :=

It seems from the arrivals controller point of view that things have improved slightly over the past few weeks. Maybe the new system is doing it a little better, maybe not. There's been a discussion amongst us that non conformers or those being punished should be sent to an arbitrary waypoint off the published route (maybe called NORTY?) so that they aren't causing grief in a pattern while everyone else is coming through?

One bizarre trend that has become apparent is that when the big delay notams go out, there actually seems to be a lot less holding. Is that coincidence or do the notams encourage flights to be more time compliant?

The recent trend, from a passenger point of view, is that we seem to be doing a lot more waiting on the ground, prior to take-off, than holding in the air, recently. I always fly in on those peak periods. Previously, became accustomed to holding well north, watching other aircraft holding with us, or do the long way around, approaching from the south via Australind:rolleyes: Not uncommon to actually load and shut, then wait for an extended period. Then taxi out (last a/c for the day), and wait , lined up, for last light before actually getting airborne. Or, aircraft lands a bit late, does a VERY quick turnaround and buggers off, when they have obviously been given a favourable slot time, and mean to make it. It does seem to have changed.

Anyone who has flown outside of this little sheltered workshop will know what a turd PH airport and it's delays are.
I'm not saying its the ATCs fault ( although as in any outfit there is clearly some incompetence there ) but the sort of delays that are being dished out at this so called " busy " airport are ridiculous.
From the time you enter PH airspace til the time you try to get a taxi home is a complete clusterfcuk and the place is well deserved to be in the 10 worst airports in the world.
As far as notam holding being a forecast , WTF ? Another WA first ? So you suggest maybe just filling the A/C and if that's not enough divert ? What a great attitude and typical of Wait Awhile.

HKF ( for a change ) is on the money. Friend of mine that does FIFO told me he is getting delayed just as much with these COBTs as ever and that he has proof that not everybody is getting stuffed around equally.
Perth airport is NOT busy in the scheme of things although the archaic procedures and ridiculous seperation do make it seem so. If Beijing, for example, applied the wonderful Perth system your delay could be tracked on a calendar.
Maybe somebody needs to go to the mining companies and let them know how much these delays are costing them, see how someone like Andrew Forrest reacts to being told PH airport is costing him 10s of 1000s of dollars a month, I'm sure he'd be happy ?

Good to see the loonies are back in force. :D

Are you suggesting ATC just forget the traffic holding NOTAMs and let the crews deal with "guess what, hold for 40 mins NOW"? At least ATC is using it's noggin and pre-empting the approaching SNAFU by warning all that there may be some severe holding based on the previous demonstrated inability of some operators to stick to their slot times.

On the ground or in the air? Of course there are going to be delays. The idea is to make them ground delays, not airborne. The times of delays will probably be very close to the same as before.

[quote-ADBF]he has proof that not everybody is getting stuffed around equally.[/quote]
Obviously if you jump the queue and cop only 10 minutes air holding you're going to look better to the SLF than the other crowd who do the right thing, take a 20 minute ground delay and then cop a 10 airborne delay.

My understanding is that they have been told, time and again, that their scheduling is creating the problem.

I doubt it.

Seems a bit ignorant to say Perth isn't a busy airport doesn't it. So many here claim overseas airports are so much busier than Australian airports quoting annual movements as the evidence, eg the Brisbane Gatwick comparison 250k vs 200k a few pages back.

Is it not obvious that a certain airport will have a maximum capacity based on the number of runways, high speed exits, taxiway structure etc. If an airport only does 100 movements per day is that a busy airport? What if those 100 movements are scheduled between 4 and 5 pm and the airport has one runway and one taxiway? Sounds like this is the case with FIFO in PH.

You can have all the bells and whistles you want helping the controller, but he is still not going to be able to put anymore aircraft on the runway than he could with just a RADAR screen and a microphone. If you look at the runway occupancy during these peaks im pretty sure you'll find there's not alot of wasted asphalt.

How pilots can pass judgement on an ATCs perfomance is beyond me. He may think he knows whats going on when really he has no idea. If you think you can do a better job. Go get your license and fix the 'problem'.

Departing Perth this morning for the East coast.

Wind 010/8, runway 03 only.

Why?

ICARUS 2001.

I queried that exact point with ATC last week, as well as others.

Reply was safety concern due Tarmac works adjacent to bays 19 -21.

I'm still scratching my head as to where those works preclude the use of RWY 03 & 06 for departures:ugh:

K-Ex.

Unless QF has built in a fudge factor for COBT, Andrew Forrest couldn't give a rats arse. He wants his workers delivered to the mines. Its the airlines and their contract price that have to sort the rest out. If the delays due holding cost money then its costings Qantas, unless they've fudged it. I would have.........

Have a think about how aircraft get from QF/Skippers/Network/Cobham to the threshold of 06. It looks like it could be done but, would it be worth the hassle/increased complexity?

So, to the ATC guys/gals out there, who are the non-comformers?