Perth - speed up - slow down

[ROH111]

I can’t help but ask F100 drivers and tonight I’ll include the Network A320 drivers, what the story is with their lack of ability to reach Beverly or Julim, on time.

Forever in a day we fly into perth, reach the fix (up to 30 seconds early, but not late) do our 250 knots then get told to vector off to rejoin final, yep, behind an F100. Tonight we had speed cancelled and a time to make Beverly, made it fine, then got told to slow down, vector off but this time, it was behind a Network A320.... who earlier was given direct to Rolob as ATC could see they had no idea of space or time.

I know it’s not just me who suffers this daily, is it lack of technology on the F100 that makes it difficult? Can you guys uplink the latest winds prior to decent? Curious to know what it is, it’s becoming frustrating.

[pilotchute]

I fly an elderly jet and making fixes at a particular time isnt sonething that we can do easily. ATC know this and "Slow to 210 for spacing" or "maintain 250" is as good as they can make it for us. Its ATC's job to manage traffic flow and they should know which aircraft can do what.

In saying that an A320 should be perfectly capable of time at fix. If crews of a particular airline are showing poor airmanship then a quick phone call to the CP should fix it.

[DUXNUTZ]

Why be so anal?

[smiling monkey]

Lack of technology would be my guess for the F100. We're talking about an airplane that was made in the 1980's. I reckon an iPad running Ozrunways is more advanced. Use that to get your JULIM / BEVLY estimates!

[VHFRT]

Why be so anal?

Yep.... clearly one of the somewhat special captains our second best airline has

[mrdeux]

I've always wondered just how ATC think we do hit waypoints at times they just happen to invent out of the blue.

[neville_nobody]

Why be so anal?

Because its an issue when you're 5000' high on profile because old mate in front can't get it sorted out.

I am told also that the ATC computer program has to bear some of the blame for the whole Feeder Fix problems in this country

[Bankstown]

Odd the Network A320 was tracking via ROLOB as they don’t generally arrive from the east on the BEVLY arrival. Are you sure about your recollection of space and time?

[industry insider]

Lack of technology would be my guess for the F100. We're talking about an airplane that was made in the 1980's. I reckon an iPad running Ozrunways is more advanced. Use that to get your JULIM / BEVLY estimates!

90s for the Oz aircraft I think? But when the regular industry users of these geriatric aircraft ask for newer more reliable ones, we are told condescendingly by the airlines operating them “they were very advanced when they were made and stand up well against today’s modern jets”

Regardless of type, any professional pilot who can’t make good a time over a fix should be sent back to school.

[Blueskymine]

Because they subtract 2 minutes from their estimate to ensure a limited slowdown.

Ive been overtaking one like he’s standing still and his estimate was way ahead of ours. We advised atc and got sequenced ahead.

Damn annoying to be stuck behind those Fokkers.

Then there’s the Fokker100 reported undershoot sheer on final....

[John Citizen]

Yes, I heard (rumour only) they (Network) have been advised from above (chief pilot) to subtract from their true estimate.

Is this true?

It frustrates me too.

Maybe we should all do the same.

[josephfeatherweight]

Australia is the only country in the world that imposes this “cross WAYPT at XX”, with the “up to 30 secs early, but not late” thrown in for good measure. I fly what would be considered a modern aircraft and the FMS has no function to readily assist with achieving these requirements - in fact, it actually throws you under the bus because the FMS displayed estimated time over a waypoint is usually about 3-4 mins later than the time you actually end up flying over it - the discrepancy appears to magically fix itself when you’ve got about 3-4 mins to run and no chance to fix it. This is not a case of unaccounted descent winds. Of course, we are aware of this and I usually just get the old whizwheel out to sort it out and achieve the requirement.
Everywhere else the the world, even where it is actually busy (eg New York), ATC just tell you what speed to fly and it all works out. What is especially frustrating is flying across the Bight at max chickens for 3.5 hours to then be required to “reduce speed to cross BVRLY at XX” - we’ve got ADSB/CPDLC - you can see where we are and what we’re doing...
By the way, I blame the system, NOT the controllers.
So, long story short, even relatively modern aircraft don’t necessarily have a function that assists with this issue.
(Other than distance to run and ground speed!)

[NaFenn]

The system is well and truley broken - the whole idea of COBT (In my mind) would be to eliminate enroute delays, and yet I lose count of the number of times we taxi off exactly on time and still cop a slow down enroute. Not to mention the "reduce... reduce... reduce... oh, uhhh max speed cancel speed restrictions" trick (or vice versa) that the turboprops always seem to cop in the terminal area.

[sunnySA]

And I thought it was "Slow Down, Go Fast, Slow Down, Go-Around"

[AmarokGTI]

Surely tech can’t be it. We have no issues meeting time requirements in a Saab 340 with UNS1W FMS, which usually agrees perfectly with the iPad estimate too.

[HighFives]

A number of other places use ETT (estimated take-off time) as the COBT equivalent, with each port factoring in taxi time based on dept runway and time of day (obviously a simplified description). Usually its ETT plus/minus 5 minutes. COBT AND GDP does none of this.
COBT and GDP is a dinosaur of a measure because its strictly airline schedule dependent, only refreshed twice a day, often very poor at re-active measures when something goes wrong (ie wx, single rwy ops). Its basically got a disconnect between whats happening on paper versus reality.

From a ‘bus perspective, all we can do is adjust cruise and descent speeds to make the crossing time, and its usually quite a ‘bastardised’ process, just as it is with departing a hold at a specified time. Don’t even get me started with CTA steps.

As a side note, OZ runways is ridiculously accurate for referencing crossing times..beats Jepp any day of the week.

[Blueskymine]

Australia is the only country in the world that imposes this “cross WAYPT at XX”, with the “up to 30 secs early, but not late” thrown in for good measure. I fly what would be considered a modern aircraft and the FMS has no function to readily assist with achieving these requirements - in fact, it actually throws you under the bus because the FMS displayed estimated time over a waypoint is usually about 3-4 mins later than the time you actually end up flying over it - the discrepancy appears to magically fix itself when you’ve got about 3-4 mins to run and no chance to fix it. This is not a case of unaccounted descent winds. Of course, we are aware of this and I usually just get the old whizwheel out to sort it out and achieve the requirement.
Everywhere else the the world, even where it is actually busy (eg New York), ATC just tell you what speed to fly and it all works out. What is especially frustrating is flying across the Bight at max chickens for 3.5 hours to then be required to “reduce speed to cross BVRLY at XX” - we’ve got ADSB/CPDLC - you can see where we are and what we’re doing...
By the way, I blame the system, NOT the controllers.
So, long story short, even relatively modern aircraft don’t necessarily have a function that assists with this issue.
(Other than distance to run and ground speed!)



Don’t know what you’re flying, but the Honeywell FMS that’s standard in most Australian buses will give you an estimate based on the current conditions to the second in which you will pass overhead the feeder fix. It’ll need a bit of managing as the conditions change, especially on the way down, but if you can’t cross the waypoint within 5 seconds of what you require, you shouldn’t be sitting in the seat.

[John Citizen]

From a ‘bus perspective, all we can do is adjust cruise and descent speeds to make the crossing time, and its usually quite a ‘bastardised’ process


The bus actually has an RTA function which works quite well in my opinion. (Within 30 seconds, and designed to keep you within 30 seconds I think).

However you often have to tweak it during descent if you really want to meet the exact time.

This is not a system flaw but perhaps just because the descent winds might be different to forecast.

Also once on descent, the FMS gives priority to maintaining descent profile compared to meeting a fix at a certain time.

I have flown with old school pilots who openly crunch numbers on the way down (ground speeds, time and distance, miles per minute etc ..without a calculator or a whizz wheel....geeze they really are so smart) as they think out aloud (or to show me how smart they can be be without the FMS) but it really is not necessary.

The people who say it (the RTA function) doesn't work just don't know how to use it.

Fair enough, whatever works best for you.

[Blueskymine]

The bus actually has an RTA function which works quite well in my opinion. (Within 30 seconds, and designed to keep you within 30 seconds I think).

However you often have to tweak it during descent if you really want to meet the exact time.

This is not a system flaw but perhaps just because the descent winds might be different to forecast.

Also once on descent, the FMS gives priority to maintaining descent profile compared to meeting a fix at a certain time.

I have flown with old school pilots who openly crunch numbers on the way down (ground speeds, time and distance, miles per minute etc ..without a calculator or a whizz wheel....geeze they really are so smart) as they think out aloud (or to show me how smart they can be be without the FMS) but it really is not necessary.

The people who say it (the RTA function) doesn't work just don't know how to use it.

Fair enough, whatever works best for you.

The RTA is okay for giving you an indication of what’s required without letting it do the job. However it’ll bring you right back to green dot if you let it take over which sometimes isn’t appropriate. Especially in a smaller airbus with higher wing loading. Not so critical in the bigger ones. I use the RTA with a selected speed to initially see what it will require in the cruise. Then I’ll select that plus 10 knots and work the rest out with descent speeds.

It it really is a piece of cake. If you can’t make the time at this point, you advise ATC and they give you vectors. Or you drop to a lower level and slow up. Green dot is a knot higher for every 1000 feet over 20. So you can get some good speed reductions down low. Especially east bound out of the jet.

Anyway, stick with it son.

[Icarus2001]

From a ‘bus perspective, all we can do is adjust cruise and descent speeds Isn't that the same for all of us flying different types? How else do you meet a feeder fix time?

[morno]

The RTA is okay for giving you an indication of what’s required without letting it do the job. However it’ll bring you right back to green dot if you let it take over which sometimes isn’t appropriate. Especially in a smaller airbus with higher wing loading. Not so critical in the bigger ones. I use the RTA with a selected speed to initially see what it will require in the cruise. Then I’ll select that plus 10 knots and work the rest out with descent speeds.

It it really is a piece of cake. If you can’t make the time at this point, you advise ATC and they give you vectors. Or you drop to a lower level and slow up. Green dot is a knot higher for every 1000 feet over 20. So you can get some good speed reductions down low. Especially east bound out of the jet.

Anyway, stick with it son.

What’s wrong with flying at green dot in any Airbus (turbulence excepted)? It’s not going to drop out of the sky. In fact even at VLS it’s not going to drop out of the sky.

Just let the automatics do their job, and then when it can’t, intervene

[Blueskymine]

You can do it if you want. But when you’re up high at green dot with less than 10 knots to VLS and she’s a bit choppy - I’m paid to keep it on the rails and provide a safe margin. Not to reduce those margins and let the automatics take care of it.

The bus is a handful when she comes back with a ‘cannot’ and hands it over to you. I hope you’re ready for it. I’ll be down low at green dot plus 10 with my feet up reading the...notams.

[josephfeatherweight]

the Honeywell FMS that’s standard in most Australian buses will give you an estimate based on the current conditions to the second in which you will pass overhead the feeder fix.
No such luck for me - have approached the FMS manufacturer for answers and they have not been forthcoming. Would like to know how to achieve over a waypoint to the second?
When you say "buses" do you mean Airbus aircraft?
The limited number of FMSs I have experience on show an estimate time over the waypoint to the minute - and that "minute" is actually (sensibly) based on the half-minute:
ie if the actual waypoint crossing time is 12:05:29(secs) it would show a crossing time of 12:05 - if the actual crossing time is 12:05:31(secs), it would should a crossing time of 12:06.
This is NOT utilising an RTA feature, however - which I don't have in the FMS installed on the aircraft I fly. Makes the "30 secs early, but not late" thingy difficult without doing it manually.
Perhaps some FMSs display an estimated crossing time to the second?
Out of interest, are ATCer's aware of these limitations?

[Bula]

You can put an RTA in seconds as well.

personally this is my process.

insert time marker

1. CI=0 (MRc)
2. Lower descent speed towards green dot.
Note: only go the Green Dot + 20 to allow for a slower descent speed to be selected on descent if winds are not as forecast unless you have an up to date wind link on ACARS.

if no luck

3. Set RTA to the assigned time minus 15 sec
( -30 sec/+0 requirement average)

if it targets green dot pull green dot +10 when above 25000’ (G loading on Alpha prot settles around this altitude and below)

4. Look at the extra track miles required to make the time (distance between RTA and time market) and how long I have to do it.

5. Descend to a new cruise altitude, allowing average 5 Kt TAS plus 1 knot green dot reduction reduction per 1000, approx.


Eg.
Nil wind, Required crossing time of 2130

difference between waypoint and RTA is 8 nm after points 1-3.

present time is 2100. 30min to lose 8 nm, or 16nm over 60 min, therefore 16 kts.

16/6 kts per 1000’ is about a 3000’ reduction in altitude.

hemispherical = descend 4000’

insert new cruise alt if required on the PROG page

Check/reinsert descent speed. RTA should do the rest.

[outside limits]

I can’t help but ask F100 drivers and tonight I’ll include the Network A320 drivers, what the story is with their lack of ability to reach Beverly or Julim, on time.

Forever in a day we fly into perth, reach the fix (up to 30 seconds early, but not late) do our 250 knots then get told to vector off to rejoin final, yep, behind an F100. Tonight we had speed cancelled and a time to make Beverly, made it fine, then got told to slow down, vector off but this time, it was behind a Network A320.... who earlier was given direct to Rolob as ATC could see they had no idea of space or time.

I know it’s not just me who suffers this daily, is it lack of technology on the F100 that makes it difficult? Can you guys uplink the latest winds prior to decent? Curious to know what it is, it’s becoming frustrating.
Maybe you should try & cross the fix at the time required rather than arriving 30sec early. Its a tolerance not a new target. Ya clown !

[Blueskymine]

No such luck for me - have approached the FMS manufacturer for answers and they have not been forthcoming. Would like to know how to achieve over a waypoint to the second?
When you say "buses" do you mean Airbus aircraft?
The limited number of FMSs I have experience on show an estimate time over the waypoint to the minute - and that "minute" is actually (sensibly) based on the half-minute:
ie if the actual waypoint crossing time is 12:05:29(secs) it would show a crossing time of 12:05 - if the actual crossing time is 12:05:31(secs), it would should a crossing time of 12:06.
This is NOT utilising an RTA feature, however - which I don't have in the FMS installed on the aircraft I fly. Makes the "30 secs early, but not late" thingy difficult without doing it manually.
Perhaps some FMSs display an estimated crossing time to the second?
Out of interest, are ATCer's aware of these limitations?


When you go to the RTA prompt at a waypoint it will give you the current estimate to the second.

The flight plan page only gives you to the minute based on your above observations. So does a time marker.

I personally use a time marker and cross check the estimate at the RTA page. Then you can see the trend and stoke the boilers or save the planet.

[josephfeatherweight]

Ah, I see, thanks for the explanation! Look forward to flying something with the RTA function!

[maggot]

On a bus, time marker, pull speed, adjust and cross to the second. Too easy

[airdualbleedfault]

I don't see how a Netflix F100 can beat any other jet to JULIM at cost index zero :rolleyes:

[No Idea Either]

RTA’s can be met to the second in a Boeing. As maggot states, I believe it can be done in an airbus too. Simple remedy, if you consistently miss the times “turn left heading 090, we will fit you in when we can.” A few instances of this and the problem should be solved. I too drag my arse in behind fokkers as well. Very painful, it’s not that hard.

[Australopithecus]

Having flown both types I am pretty confident in easily achieving a fix time +/- 5 seconds or so. I don’t have to, of course, but I choose to out of respect for my fellow airmen and the long suffering controllers.

That ATC has subscribed to the odd notion of central control is not the controllers’ fault, nor ours. It would be so much easier if a metering fix crossing time was part of our initial clearance. Why, pray tell, does ATC waste resources trying to predict crossing times when they could simply assign them hours prior, and let punitive holding be the wages of sin (or poor nav skills)?

[Capt Fathom]

It’s not going to drop out of the sky.
Just let the automatics do their job, and then when it can’t, intervene.
I thought you said it wasn’t going to drop out of the sky!

[neville_nobody]

That ATC has subscribed to the odd notion of central control is not the controllers’ fault, nor ours. It would be so much easier if a metering fix crossing time was part of our initial clearance. Why, pray tell, does ATC waste resources trying to predict crossing times when they could simply assign them hours prior, and let punitive holding be the wages of sin (or poor nav skills)?

I have been told that the current ATC technology is unable to do this and has to wait until everybody is closer in. Maybe someone in ATC could elaborate?

[rockarpee]

Time marker on BOTH Airbus and Boeing, open speed window and drive to the marker. Sorry I don’t understand the issue here......I plead ignorance regards other types

[Capn Bloggs]

What is especially frustrating is flying across the Bight at max chickens for 3.5 hours to then be required to “reduce speed to cross BVRLY at XX” - we’ve got ADSB/CPDLC - you can see where we are and what we’re doing...
And what about the other 20 aircraft trying the same thing, Joseph? Why should we clear out of your way just so you don't have to change speed?

I fly what would be considered a modern aircraft and the FMS has no function to readily assist with achieving these requirements - in fact, it actually throws you under the bus because the FMS displayed estimated time over a waypoint is usually about 3-4 mins later than the time you actually end up flying over it - the discrepancy appears to magically fix itself when you’ve got about 3-4 mins to run and no chance to fix it.
Don't blame the system for your inadequacies. COBTs/Feederfix times work just fine where I sit, and I don't even have decimal minutes displayed on my FMS ETOs.

[sunnySA]

I have been told that the current ATC technology is unable to do this and has to wait until everybody is closer in. Maybe someone in ATC could elaborate?
Because Industry was sold and bought a pup, the core metric is OTP based on departure rather than arrival. COBT -5 to +15 which can lead to a cluster of arrivals even though everyone is "compliant".

[Australopithecus]

I have been told that the current ATC technology is unable to do this and has to wait until everybody is closer in. Maybe someone in ATC could elaborate?

I know that it’s ancient technology and all, but when I flew in Europe 30 or so years ago we would get crossing times 6 to 24 hours earlier. In 12 months of 737 ops (including 4 or 5 times a week into Heathrow)I don’t reckon I held a total of six hours. In 1989 European movements were the same as Australia’s in 2097.Give or take.

That holding was either due to crazy winds, Speedbird Concorde descending on vapours or other random unpredictable furballs being coughed up by the system.

[josephfeatherweight]

Capn Bloggs - I thought we were mates!?
I think you’ve got the wrong end of the stick there, I didn’t say anything about other aircraft “clearing out of my way”, did I?
I just think the system could be better than watching a whole bunch of aircraft fly at high (planned) fuel flows/speeds across the country, and then be slowed to min speed approaching a waypoint, instead of sequencing the whole process earlier in the piece. I’m not all that swept up on the ATC system, so maybe it’s a pipe dream.
As for blaming a system for my inadequacies, I don’t really think I did that either - can you re-read my post and perhaps clarify where I got you all hot and bothered?

[601]

in fact, it actually throws you under the bus because the FMS displayed estimated time over a waypoint is usually about 3-4 mins later than the time you actually end up flying over it

Doesn't anyone use an E6B any more?

[porch monkey]

A what???....

[morno]

I thought you said it wasn’t going to drop out of the sky!


No, it won't. I mean if the automatics can't make an RTA because even by flying at green dot etc. it's not achievable, then descend or whatever is required.

But in several years of flying the 'Bus, this whole idea of not going near green dot because it's dangerous, is just plain wrong :ugh:. Sure, in turbulence, give yourself a bit more margin. But smooth air, really? :hmm:

It's just like those who want to throw a few extra knots onto the VAPP when the autothrust is doing a brilliant job of maintaining VLS+5. You already have a margin, it's called that +5kts that Airbus allows for the autothrust. Even more questionable when the landing distance check they performed just before descent shows a margin of stuff all, and they want to throw some more speed on and now make it an unknown landing distance.

Sounds typically Australian, to re-invent the wheel rather than just letting the aircraft do what the manufacturers designed it to do, with plenty of fat already built into it.

[Bula]

Morning, sorry to say but you’re incorrect.

if you still have access to the stall charts, have a look at the compressibility effect on stall speed above 25000’ on the 320/321. Plenty of occasions where V alpha port will exceed Vls and green dot in a turn.

the AP will disconnect, and you will be hand flying at max Alpha. If you’re close to the Rec max, you’re only option will be to descend to regain energy.

or.....

you can go Green Dot + 10.

[josephfeatherweight]

Doesn't anyone use an E6B any more?
Doesn't anyone read original posts anymore?

[machtuk]

This is an interesting thread, only in Australia do we make flying difficult! Having flown in a few countries I just shake my head at the 'best practice' we Aussies have to have:-) I often had to use that thing in our skulls to work out a crossing time without any FMS with my back up plan........UNABLE!:-)
The 'Bus' I used to fly was too easy, killed a lot of basic flying skills & brain capability:-(
Off topic slightly but when I first joined the bus brigade years ago I recall going into Syd 34L on a Viz day, got to about 13miles & turned all the automatics off to have a hand drive, you should have seen the Capt sit bolt upright instantly like he had been in an electric chair & the look on his face said it all!:-)...that was the best day I could recall:-)
We are all pilots, we are meant to be adaptable:-)

[maggot]

This is an interesting thread, only in Australia do we make flying difficult! Having flown in a few countries I just shake my head at the 'best practice' we Aussies have to have:-) I often had to use that thing in our skulls to work out a crossing time without any FMS with my back up plan........UNABLE!:-)
The 'Bus' I used to fly was too easy, killed a lot of basic flying skills & brain capability:-(
Off topic slightly but when I first joined the bus brigade years ago I recall going into Syd 34L on a Viz day, got to about 13miles & turned all the automatics off to have a hand drive, you should have seen the Capt sit bolt upright instantly like he had been in an electric chair & the look on his face said it all!:-)...that was the best day I could recall:-)
We are all pilots, we are meant to be adaptable:-)
Why would he be surprised? I mean, if it's unusual to use that level of automation, or lack thereof, a minor briefing point may have been in order.
Very impressive though :hmm:

[Capt Fathom]

you should have seen the Capt sit bolt upright instantly like he had been in an electric chair

Generally having your mate suddenly decide to show you how it's done would get your attention. :=

[C441]

A bit left-field, but if you're on an Airbus with the capability, load a time marker with the desired time and start descent when the FMS tells you to.
On the Flt Plan page of the FMS, keep an eye on the altitude at the time marker and the altitude at the required position. Adjust the speed as required to match the altitudes and, voila, you'll be there within a second or two. Assuming you're on descent, if you're higher at the time marker you'll be late at the position and vice versa. (It also assumes you have some brain space left at the end of a long sector!)

I'm sure not all aircraft have this capability, but if yours does, try it.

[Capn Bloggs]

I just think the system could be better than watching a whole bunch of aircraft fly at high (planned) fuel flows/speeds across the country, and then be slowed to min speed approaching a waypoint, instead of sequencing the whole process earlier in the piece.
My point was, it doesn't matter how far away you are, me and all my F@kker mates haven't even departed yet. When we pop up at the same distance to Perth as you, something's got to give. There's no point in sequencing further out because any closer-in departures will mess the whole string up.


As for blaming a system for my inadequacies, I don’t really think I did that either - can you re-read my post and perhaps clarify where I got you all hot and bothered?
You were having a crack at our "unique" Feeder Fix time system and how your "FMS" was 3-4 minutes out all the time and why didn't ATC just give us speeds to fly. I don't agree. The pilots can do it (some better than others), why just sit there looking out the window?

[Capn Bloggs]

They also clog up the carpark! :}

[Capn Bloggs]

Because its an issue when you're 5000' high on profile because old mate in front can't get it sorted out.
Nev, could you explain why you'd end up 5000ft high because of the A/C in front [going too slow?]? :confused:

[Blueskymine]

Morning, sorry to say but you’re incorrect.

if you still have access to the stall charts, have a look at the compressibility effect on stall speed above 25000’ on the 320/321. Plenty of occasions where V alpha port will exceed Vls and green dot in a turn.

the AP will disconnect, and you will be hand flying at max Alpha. If you’re close to the Rec max, you’re only option will be to descend to regain energy.

or.....

you can go Green Dot + 10.


But he’s been on the airbus for a few years now.....

This attitude really worries me. He doesn’t know what he doesn’t know.

I’ve got no problem being at green dot down low in a hold I’ll chuck a margin on for the turns if I’m heavy. Preferably though I’d be descending at green dot on the hold. Not flying circles in Alt.

Up high even in smooth air. No. You’re asking for trouble in a 320/321.

In a 330/380/350 (tel:330/380/350). No problem. Big wing. Big margins.

[neville_nobody]

Nev, could you explain why you'd end up 5000ft high because of the A/C in front [going too slow?]?

F100 is 2 minutes in front of us on feeder time, but blocking our descent clearance. We can't do anything as any change in speed will mess our feeder time. So we are left high and dry waiting for the F100 to start descending and accelerate away.

It appears that the F100 flies slow in the cruise but then accelerates the descent to meet their time. Obviously if they are late on their time the more an issue it is for the following aircraft. I have had it a few times now, so it wasn't just a one off event where someone got their time wrong.

[airdualbleedfault]

Nev, could you explain why you'd end up 5000ft high because of the A/C in front [going too slow?]? https://www.pprune.org/images/smilies/confused.gif
Is that a serious question bloggs? I would have thought if the aircraft behind was being slowed down it would screw their descent profile not too mention the aircraft in front is probably now flying slower than ATC planned and therefore reduced seperation/following aircraft not able to descend, it's not rocket surgery

[AerocatS2A]

We used to manage ok in the Britishly Awesome 146. No winds in the box, no time markers, no VNAV, no seconds or decimal minutes on the FMS, no help. It was simple enough provided you understood that the FMS time did not round up at all, if your fix time was 1205 and the box said 1205 then you'd be overhead sometime between 1205:00 and 1205:59, i.e., you were going to be late. If the box said 1204 then you would be there between 1204:00 and 1204:59, half a chance you'd be there within the 30 seconds early buffer. A quick bit of maths to work out an average ground speed and then adjust indicated to achieve it. Unfortunately our only answer to "what's your planned indicated on descent?" from ATC was "haven't got a clue, just suck it and see!" I would err towards being early rather than late because it was easy for the bird to lose more time if asked but very difficult to make up any time.

[Capn Bloggs]

F100 is 2 minutes in front of us on feeder time, but blocking our descent clearance. We can't do anything as any change in speed will mess our feeder time. So we are left high and dry waiting for the F100 to start descending and accelerate away.
It appears that the F100 flies slow in the cruise but then accelerates the descent to meet their time.
OK, fair enough. I have had the same with QF 737s. Dunno why they can't cruise at somewhere near their descent speed. Perhaps they're using RTA... ;) You could just demand a descent from ATC. That'll scare the f@kkers.

I would err towards being early rather than late because it was easy for the bird to lose more time if asked but very difficult to make up any time.

:D :ok:

[zanthrus]

Who gives a f#ck if your within 30 sec (or not). I will be there when I will be there and ATC can sort it out. It's their job as the second best ATC in the world to do so.

[haughtney1]

The whole Oz ATC setup is decidedly third world masquerading as first world. In a country as vast as it is, with even vaster oceanic airspace....who in their infantile brain thought that trying to sequence traffic once it was within 35 min flying time of destination..was a sensible idea?
I know who....a person or organisation with no clue as to how aircraft are flown or operated...that’s who....or better yet an organisation or person who wants to reimagine aviation their way...

[josephfeatherweight]

who in their infantile brain thought that trying to sequence traffic once it was within 35 min flying time of destination..was a sensible idea?
haughtney1 - I couldn't agree more...

[Ollie Onion]

Wow, this is really being over complicated. Get an RTA, put the time marker in, slow to a speed that you are comfortable with (I personally will go to Green dot +10kts), enter that as a descent speed and if you can't make the RTA then 'JQXXX, unable to comply with RTA, request vectors/hold'. I am not going to spend my time trying to work out complicated equations to try and finesse an RTA that a good amount of the time is just unrealistic or puts the aircraft close to an undesirable state. Why bust your balls stressing to make an RTA, throw it back to ATC, if they want to give me an 8-10 minute delay and 100 nm to try and achieve it then they can take some responsibility for it.

[Global Aviator]

Yep there is nothing wrong with telling ATC unable.

It amazes me the amount of guys that jump to speed/ speed brakes, etc on the very first breath from ATC.

Wait, comprehend, have a look, if it can be done great, if not say so.

[machtuk]

Generally having your mate suddenly decide to show you how it's done would get your attention. :=

You missed the point! Why do some always twist things around in here to make them feel good?
For the benefit of others who aren't judgemental. My briefing did include a possible hand flown App. When I disengaged the A/P I also disengaged the A/T.
My point was that it showed this particular Capt most likely wasn't confident to hand fly himself hence his "oh sh1t" reaction!

[Angle of Attack]

Because there is a few misguided pilots on the 737 that always say it’s most efficient to fly at Optimum and don’t want to descend when given a slow down, sure it’s most efficient for range but range isn’t the issue if you have a slowdown. If your at optimum like most you can hardly slow down at all, mid to high twenties is the far best altitude for slowing down, holding etc, as long as there’s no weather etc at that level.

[Blueskymine]

You missed the point! Why do some always twist things around in here to make them feel good?
For the benefit of others who aren't judgemental. My briefing did include a possible hand flown App. When I disengaged the A/P I also disengaged the A/T.
My point was that it showed this particular Capt most likely wasn't confident to hand fly himself hence his "oh sh1t" reaction!

His ‘oh ****’ comment wasn’t the fact he was not confident in his ability to fly autothrust off, but more than likely his confidence in YOU flying it. Remember - the buck stops with the 4 stripes in the left even if it was your fault. They will be soc’d and face the sim and retraining. It also helps if you brief a/thr off.

Just ask two captains recently who had bad days with the same FO capturing the GS from above and subsequent go arounds. Not pretty.

[Capn Bloggs]

If your at optimum like most you can hardly slow down at all, mid to high twenties is the far best altitude for slowing down, holding
Just like the 7x7 FCOM says... :ok: Probably the Fokker one too!

[amberale]

OK, fair enough. I have had the same with QF 737s. Dunno why they can't cruise at somewhere near their descent speed. Perhaps they're using RTA... ;) You could just demand a descent from ATC. That'll scare the f@kkers.



:D :ok:
And here is the whole problem.
All of you Fockers have different profiles and all want priority.
If you are 5,000ft above profile then you aren’t going to be able to maintain your companies registered profile speeds inside 30nm.
You will then get stuffed around by APP.
What else are we supposed to do???
Even if you were all driving Bongo737s or scarebus A320s you would fly them differently and need to be “adjusted”.

Bloggs you are correct about the close in departures and then add CB-ML, TWB-BN type flights which all have the same priority as the sky gods and you can guess the complexity.
Try to chill and work together, if the guy in front of you looks like the are going to impede your descent ask for a vector ffs.

[neville_nobody]

Try to chill and work together, if the guy in front of you looks like the are going to impede your descent ask for a vector ffs.

Problem is we don't know they are there until we start descent. Then we get vectored off and have to speed up our descent with thrust on to make our time. I have also seen this scenario totally confuse ATC as they have the aircraft 2 minutes apart at the fix but virtually on top of each other. Constant IAS all the way from everybody would probably fix the problem but the Fokkers don't seem to do that for whatever reason.

[34R]

If there are crews that are providing false times in an attempt to minimise their delay, and other crews that have no intention of meeting a time and leaving it to ATC to sort out, is there any wonder then of the speed up slow down scenario??

Some of you seem to be going out of your way to contributing to the problem you are so vehemently complaining about!

[Blueskymine]

F100 is 2 minutes in front of us on feeder time, but blocking our descent clearance. We can't do anything as any change in speed will mess our feeder time. So we are left high and dry waiting for the F100 to start descending and accelerate away.

It appears that the F100 flies slow in the cruise but then accelerates the descent to meet their time. Obviously if they are late on their time the more an issue it is for the following aircraft. I have had it a few times now, so it wasn't just a one off event where someone got their time wrong.

The old Fokker has a slow cruise Vmo, but she boogies at the crossover and at this point can match it with an IAS similar to modern jets.

So I guess that’s how they play their game. Personally I’d descend earlier and fly at the crossover for longer if I was driving one, so as not to disrupt the flow behind me. But it would seem a 2:1 profile is pretty common on the things. I’d regularly see one 10K above me 5nm in front. They’d at some point cross through our level and be below us.