Australia, New Zealand & the Pacific Airline and RPT Rumours & News in Australia, enZed and the Pacific

Perth - speed up - slow down

Old 3rd Aug 2019, 15:27
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Perth - speed up - slow down

I canít help but ask F100 drivers and tonight Iíll 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 itís 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, itís becoming frustrating.
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Old 3rd Aug 2019, 15:57
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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.
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Old 3rd Aug 2019, 16:19
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Why be so anal?
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Old 3rd Aug 2019, 17:03
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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!
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Old 3rd Aug 2019, 18:16
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Originally Posted by DUXNUTZ View Post
Why be so anal?
Yep.... clearly one of the somewhat special captains our second best airline has
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Old 4th Aug 2019, 00:05
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I've always wondered just how ATC think we do hit waypoints at times they just happen to invent out of the blue.
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Old 4th Aug 2019, 00:20
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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
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Old 4th Aug 2019, 00:46
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Odd the Network A320 was tracking via ROLOB as they donít generally arrive from the east on the BEVLY arrival. Are you sure about your recollection of space and time?
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Old 4th Aug 2019, 01:15
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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.
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Old 4th Aug 2019, 01:32
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Because they subtract 2 minutes from their estimate to ensure a limited slowdown.

Ive been overtaking one like heís 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 thereís the Fokker100 reported undershoot sheer on final....
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Old 4th Aug 2019, 01:45
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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.
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Old 4th Aug 2019, 02:11
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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!)
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Old 4th Aug 2019, 02:31
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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.
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Old 4th Aug 2019, 02:43
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And I thought it was "Slow Down, Go Fast, Slow Down, Go-Around"
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Old 4th Aug 2019, 03:14
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Surely tech canít 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.
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Old 4th Aug 2019, 03:31
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many elements

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 Ďbus perspective, all we can do is adjust cruise and descent speeds to make the crossing time, and its usually quite a Ďbastardisedí process, just as it is with departing a hold at a specified time. Donít 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.
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Old 4th Aug 2019, 04:23
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Originally Posted by josephfeatherweight View Post
Australia is the only country in the world that imposes this ďcross WAYPT at XXĒ, with the ďup to 30 secs early, but not lateĒ 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 youíve 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 ďreduce speed to cross BVRLY at XXĒ - weíve got ADSB/CPDLC - you can see where we are and what weíre doing...
By the way, I blame the system, NOT the controllers.
So, long story short, even relatively modern aircraft donít necessarily have a function that assists with this issue.
(Other than distance to run and ground speed!)

Donít know what youíre flying, but the Honeywell FMS thatís 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. Itíll need a bit of managing as the conditions change, especially on the way down, but if you canít cross the waypoint within 5 seconds of what you require, you shouldnít be sitting in the seat.
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Old 4th Aug 2019, 04:58
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From a Ďbus perspective, all we can do is adjust cruise and descent speeds to make the crossing time, and its usually quite a Ďbastardisedí 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.
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Old 4th Aug 2019, 05:33
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Originally Posted by John Citizen View Post
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 whatís required without letting it do the job. However itíll bring you right back to green dot if you let it take over which sometimes isnít 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 Iíll select that plus 10 knots and work the rest out with descent speeds.

It it really is a piece of cake. If you canít 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.
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Old 4th Aug 2019, 05:57
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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?
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