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CaptainLars

VOZ Virgin Australia kg or lb?

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Hi all,

I wonder if anyone knows if Virgin Australia uses kg or lb? What does Qantas use?

Any idea on their CI?

I'm currently doing some flights with the VOZ 77W and after thinking a lot, I decided to use lb for Virgin Australia, but sincerely I don't know. Could just as well be kg since the Aussies appear to be more "european" than e. g. the U.S.!

Regards

Lars

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British history mate, I'd advise using kg,  the CI probably varies, and I prefer a fixed mach on those oceanic routes where time and place are important. M084 is a nice round number.

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Thank you very much.

 

8 hours ago, downscc said:

British history mate, I'd advise using kg,  the CI probably varies, and I prefer a fixed mach on those oceanic routes where time and place are important. M084 is a nice round number.

Do they have a fixed time when to be at waypoint VWXYZ over the Pacific Ocean? And how big could their margin be, e. g. "between 0945 and 0955"?

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10 hours ago, CaptainLars said:

Thank you very much.

 

Do they have a fixed time when to be at waypoint VWXYZ over the Pacific Ocean? And how big could their margin be, e. g. "between 0945 and 0955"?

You file a flightplan with speeds and receive a clearance, and while in Oceanic control the position reports provide actual time at fix and estimated time at next fix.  Since winds vary, I'm not sure what the 'margin' is but +-10 min seems reasonable given the distance between waypoints.  Actually, since route densities in the Pacific are very light I wouldn't be surprised if CI speeds were used.  I expect alarms will be raised after 15-20 min and other aircraft will start calling you.  This certainly isn't the case on the NATS where your clearance includes a speed and that is what you fly.

Edited by downscc
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2 hours ago, downscc said:

You file a flightplan with speeds and receive a clearance, and while in Oceanic control the position reports provide actual time at fix and estimated time at next fix.  Since winds vary, I'm not sure what the 'margin' is but +-10 min seems reasonable given the distance between waypoints.  Actually, since route densities in the Pacific are very light I wouldn't be surprised if CI speeds were used.  I expect alarms will be raised after 15-20 min and other aircraft will start calling you.  This certainly isn't the case on the NATS where your clearance includes a speed and that is what you fly.

Now that you mention it I recall Kyle saying something very similar about the Pacific being all about timing.

Thank you again.

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Both NATS and Pacific require that you pass your points on time, but the increased traffic over the NATS, combined with the narrower corridor, requires the use of fixed speeds. Over the Pacific, you aren't really assigned a speed as much as you're required to simply hit your times (in comparison with the busy times on the NATS where you have that assigned speed to be extra sure you're hitting your times). Additionally, while your aim is to hit your times, if you simply report that you will be off your time in excess of the variance, a controller can provide corrective action while you remain in compliance with the reporting requirement. This is provided automatically if you have ADS-C (yes, 'C').

With this in mind, when you're out in procedural airspace, it's probably a better idea to operate at a constant Mach, or have a flight plan that changes that speed over the waypoints you cross to avoid speed variations in CI due to changes in wind and so on. When in oceanic procedural (timed) airspace, one must keep in mind that you're being spaced based on times to known points. If you cross point X at 1200Z, the next person cannot pass it until 1215Z. Given the issue that this is all about people being in a specific spot at a specific time, relative precision in your timings is an obvious necessity. If you cross the next fix 10 minutes late and the person behind you is still on time, you're now only 5 minutes separated of the 15 minute requirement. This is a problem.

...but the difficult part of the aforementioned problem is that the controller is playing chess in the dark. Procedural airspace does not have radar (though most have some sort of visual plotter to help the controller visualize the situation, based on the timings/reports - they just can't separate based on its information instead of the actual times), so you're really trusting the reports that come to you from the pilots and/or their automation to ensure you don't put planes together. For those of you studying for your IR and wondering about all those compulsory reporting points on your chart that you don't have to report over, that's only because you're in radar coverage. Back when radar coverage wasn't so complete (or when radar fails), those points were (/are) compulsory to report over, specifically because the controller had (has) to use procedural/timed separation instead of radar separation to ensure aircraft aren't too close to each other.

 

Pertaining to getting a nasty-gram: if your time varied by more than +/-2 minutes (calculated as bool (Abs(Crossed-Planned))>2) on the NATS, or +/-3 minutes in FAA land, your error wound up coming across my desk.*

*Worth pointing out that there is a major discrepancy in the various documents, and it is something that we discussed with all of the Oceanic ATC providers, operators in that airspace, and some of the regulatory agencies. The discussions are ongoing and still haven't been resolved. Even FAA internal docs bounce between +/-2 and +/-3 (surprise...), though controllers are told to look for excess of +/-3 per the 7110.82D.

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Thank you Kyle. So that means that the margin would be +-2 or 3 minutes.

What about random tracks? I figure traffic is so low there that there wouldn't be a margin so narrow. Perhaps +-20 minutes?

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7 minutes ago, CaptainLars said:

Thank you Kyle. So that means that the margin would be +-2 or 3 minutes.

On the NATs, +/-2 is what NATS UK sent us as out of compliance.

Over the Pacific, it was +/-3, because that's how the FAA controllers are taught (in fact, it's now a script that runs and auto-reports anything out of compliance - and the script is based off of the word in the .82D).

8 minutes ago, CaptainLars said:

What about random tracks? I figure traffic is so low there that there wouldn't be a margin so narrow. Perhaps +-20 minutes?

No difference. The rule is globally applied for the airspaces in question. In fact, I'd argue that stricter requirements would be necessary on random tracks. Random tracks are where we saw more deviation (by many orders of magnitude), and losses of separation. I attributed this to the lack of standardized routing, which usually meant that they would get cleared on a slightly different route than what was filed, but wouldn't update the plan in the box. This would put them off the cleared route and potentially in conflict.

When flying a track, you'd get cleared on the track. The route is set and known, and not going to change. When on a random track, the isn't on one of the major tracks, but that doesn't necessarily mean that it's farther away from other aircraft, or less of a threat.

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If an aircraft takes off in Tokyo, heading San Francisco, with a delay of 20 minutes, for example, do controllers get informed? I imagine that it would be very hard to make up for a 20-minute-delay and reaching your first oceanic waypoint in time.

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Get routes from flightaware. Australia has better coverage than America, they include the full flight plan including speeds and altitude

https://flightaware.com/live/flight/VOZ1/history/20170308/0040Z/YSSY/KLAX

DCT ENTRA H133 MATLA Y43 BANDA DCT CBULA/N0490F330 DCT 27S160E DCT 25S163E DCT 20S170E DCT 15S176E DCT 10S179W DCT 05S174W/N0490F350 DCT 00N170W DCT 06N165W DCT 12N160W DCT 17N155W DCT 21N150W/N0480F370 DCT 24N145W DCT FIZEL R578 FICKY

If you are unfamiliar reading a plan, the text after a waypoint like CBULA tells you the speeds and flight level. a Nxxxx means you are in econ cruise using the cost index, if you are told to set mach speeds you'd have instead of Nxxx Mxxx such as M84F350 for flight level 350 and mach speed .84

Looks like no mach speeds just econ cruise. I cannot find a cost index for their fleet but some 777 competitors use 50-80 or Emirates, go all out and use 400! - David Lee

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12 hours ago, CaptainLars said:

If an aircraft takes off in Tokyo, heading San Francisco, with a delay of 20 minutes, for example, do controllers get informed? I imagine that it would be very hard to make up for a 20-minute-delay and reaching your first oceanic waypoint in time.

It's a little more robust than this, luckily. While all plans go through the system and metered out (particularly in the EU - see "CFMU") in an effort to plan ahead for demand issues (i.e. lots of aircraft in a particular window of time), your clearance into oceanic areas is received before entering those areas.

If you fly the 777's Tutorial #1.5, you'll be able to see some of the simulated exchange just before entering the oceanic segment (you can simply read through it, as well, if you don't feel like flying the whole thing). When you call up for your clearance, the controller will check the track that you requested to see if there is space still available for you (assuming your earlier "I'm 20 min late in the Pacific" example). If there is, you'll get a clearance. If you're out of sequence, you'll likely get a time condition basically saying you need to cross X before/at/after a set time. In the case of the NAT region, you also specify your "backup" track in your initial clearance request, so that the controller can shift you over there if the primary isn't available (due to a delay, etc.).

With the Pacific, there's a lot more room, and it's slightly less organized than the NAT region, so 20 minutes shouldn't be a showstopper. Either way, the delay is adjusted to in real time (partially the reason we have controllers in the first place, if you think about it - they're there to adjust to things in real time and tactically address changes). The plan originally filed was filed for a set time. A delay was incurred, which affected this earlier planned time. When a controller starts working your flight plan, it becomes "active" in the system, and the flight (and now active plan) get a vague ATD (actual time of departure) in the system once you first get snagged on radar (there's a bit more to it than that, but that's for another discussion). That ATD can be used in any traffic management planning, to include checking for route conformance across the procedural segment. Even so, when calling for clearance, the controller will look once more for any conflicts and adjust the timing/routing as appropriate.

That help at all?

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15 hours ago, CaptainLars said:

If an aircraft takes off in Tokyo, heading San Francisco, with a delay of 20 minutes, for example, do controllers get informed? I imagine that it would be very hard to make up for a 20-minute-delay and reaching your first oceanic waypoint in time.

In addition to what Kyle said above, I remember when I used to listen to a lot of ATC in the 80s and 90s that many flights on oceanic routes would get a wheels-up time ("no later than") during the clearance delivery. If they couldn't make that time, they would have to receive a new clearance. This way there would be no unexpected 20-minute delay for the controllers downstream. I don't know whether this is still done today.

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6 minutes ago, wsmeier said:

I don't know whether this is still done today.

Wheels up times are still in use, but the requirement comes from different spots. Could be a wheels up for congested local airspace, airspace a few ARTCCs/FIRs over, or the oceanic sectors. The latter, though, has been cut down through the use of RLatSM tracks in the NAT region (basically, reduced separation, provided the aircraft is properly equipped, etc.).

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