VB in the Wind Tunnel

[The_Cutest_of_Borg]

Ok, please do not take this as a QF sling at VB, but I gotta know..

The scene: Anywhere there is a Jetstream.

The cast: Two plucky airliners battle the hurricane. One, wearing a White Rat is considerably lower than the other, 15-20000 feet in some extreme cases.

The red-adorned one is sitting at "optimum alt", but barely making headway.

The question is, why?

Sitting at optimum in a 180 knot headwind makes no sense when you can get 100 knots plus or more groundspeed cruising in the 20's. Your break-even fuel burn comes way down in such circumstances.

This also goes on to the punctuality question. I said in another thread that I regularly get around 85% departures on time but my arrival punctuality would be somewhat better than that by using various methods such as the one described above.

So why does VB do it? Surely it is costing them money.

Once again, not a dig, just wish to know.

PS: on another track, why do airlines always take DEPARTURE times as the punctuality yardstick? I am often early and it never seems to offset the late recorded departure. Who cares if you are 4 minutes late if you arrive 2 minutes early?

[GT-R]

The most important thing according to our passengers is departure on time, not arrival on time.

Sounds strange, but the customer is always right !

[Keg]

Sorry GT, I disagree. The customer likes to think that they are always right. Often though they need to be better educated. I don't see anyone attempting to do that! :(

[Sperm Bank]

G'day Borg. The company want us to as much as possible fly to the flight plan. That is, the cost index and flight level. Some of us look at the situation you describe above and throw on extra gas and fly lower to maintain the schedule. I don't like getting in 30 mins late if I departed on time and think it is very poor customer service. For justification we say turbulence was giving us grief etc, sure you get the picture. A lot of the younger guys don't think outside the box just yet.

[Dehavillanddriver]

I asked someone who reckons that they know, and this is what he said....

One significant reason why VB cruise higher is that fuel makes up a far greater percentage of the TRUE operating cost of the VB aeroplanes than it does in QF.

This is not because of the hedging policies that may or may not be in place at either operator, but because of the age of the aeroplanes and the contractual arrangements that exist for each aeroplane with regards maintenance and maintenance reserves.

For VB crew are a fixed cost vs a variable cost and as such don't enter into the equation, neither do lease standing charges per month.

The flight planning system optimises on the basis of cost figures input for fuel at each port and also maintenance per hour per airframe and based on those costs picks a level.

It isn't fool proof, particularly with really strong winds, but except for the extremes it mostly comes up with a cost effective altitude.

Here is a QF question - what do you guys get told about cost index and cruise speeds? We often see, as you have suggested, white aeroplanes steaming past at a great rate of knots, and the fuel burn must be horrendous - to say nothing about the noise in the pointy end!! - that isn't a swing at QF either, just an observation - I even heard a QF 800 down at 22 grand on Saurday - is that normal??

[Keg]

Dhd, it isn't abnormal. I've been across to Perth and the highest I got was 26K. Bumps was the main reason but better ground nm/kg was also not a bad trade off for getting in on time instead of an hour later for 35K. Out of time at the moment but will come back tomorrow.

[Three Bars]

DH driver,

Without getting into a lecture on jet aircraft performance - I don't think I could remember it all anymore anyway - what it comes down to is specific ground range (SGR). And please, if I'm telling you to suck eggs, forgive me, but it does explain the answer to your question.

Going lower, under a very strong jetstream, may indeed send your fuel flow up, but you might also get a huge increase in groundspeed (maybe 60-100 knots on occasions). Specific ground range is a measure of ground miles covered per tonne of fule burnt, so if your groundspeed goes right up (even though your fuel flow has also increased) you may, in fact, be better off at the lower level. On SYD-PER flights, I remember a captain on the 747 telling me that he left late, got in early and burnt less gas going down low.

Last week SYD-MEL, we flew at FL240 for a headwind of 35 knots. The guys up high were getting 130 knot headwind. For a TAS of 480, this represents nearly a 20% increase in groundspeed. Therefore, you could afford a 20% increase in fuel flow and still break even for the sector. Even if it cost you fuel, you could possibly make up 8-9 minutes for a few hundred kilos of gas on a 1 hour sector. In QF we are not given restrictions on cruising levels - it is left up to us (so far) to manage the flight.

PS For all the conspiracy theorists, such tactics (in my experience) are not flown to get in front of our competitors - rather it is done to try to get back on schedule.

[amos2]

I really can't believe all this nonsence!

I mean, if you guys gotta have this discussion, on this website, to work out whether you should fly at 35k into 150kts or go down to 22k into 50kts well, you know, you really should get another job!

[The_Cutest_of_Borg]

DHdriver (ignoring amos's little outburst for a bit)... QF used to operate on a fixed cost index for all 767 operations, but a few years ago moved to a variable cost index in an attempt to better match the conditions of the day to the scheduled flight time.

As KEG says, it is not unusual to cruise all the way to Perth in the 20's and it is not unusual to be actually flight planned in the 20's as well, leaving aside the judgement of the Captain for a bit.

Obviously there are two different schools of thought in operation here.

In relation to what you say about crew costs, QF crew costs are fixed for each domestic flight as well. Each flight is worked on a schedule based on historic data and the crew is paid accordingly no matter what the conditions of the day are. The only variable then comes down to flight time and concommitant maintenance costs, in which case the advantages of doing it faster are self-evident.

To sum it up, I still need to be convinced that VB are saving money doing it the way they do it.

Maybe there is something in the equation still to be canvassed here.

[Suffering Sucataash]

Yep, the pax do notice on time departures and with often only 35 minute turn arounds on the 73's you can't do it without ontime arrivals as well.

Latest directives though seem to be making it harder and harder though. We were going to be able to get the final load sheet via ACARS on the taxi out, now we wait at the gate. TOW increases of more than 500kg now require a new T/O card even though it's inside the buffer. Talk also of 500kg less also requiring a new card to increase to derate. Could in the past call ready in the one minute cabin prep before T/O, now we have to wait for F/A's to be seated.

Enroute we are limited to 300kts on descent in the 800 as they don't trust us to not use speed brake over 300kts. VB seem to do as they please.

Now limited to 250 kts below 5000 feet, 210 kts at 12 nm and flap 5 speed (around 165kts) at G/S intercept, no such limit at VB I bet. In fact I've heard a number of stories of QF A/C, being infront and below VB, being slowed and vectored so that VB could go number one as ATC believe they are quicker.

Laughter rings in the ears, proffessional pilots - where?

I now hear many asking why bother, I think we will see more and more rats at 410K with VB in the wind tunnel.

Just doing it for the money now.:sad: :(

[Sperm Bank]

Yet again amos you astound us with your outbursts. There is a perfectly normal conversation going on here between the lads at DJ and QF. Please feel free to contribute something constructive and blow us away with some of the wisdom you gained over the past 50 years, otherwise please go away!

I think QF limiting your speed is a bit cute. We are often asked to maintain 320 to 20 miles and as long as they get us down it is generally okay. In a heavy 800 with winglets it can get exciting if they keep us high but that is rare.

[The_Cutest_of_Borg]

Yeah SB, they used to trust us in QF to be able to manage that situation as well... then a couple of lowest common denominators spoiled all that.

It will happen with VB too as some stage... just wonder what the response of your management will be.

I get sick of Fly-By-FAM (Flight Admin Manual)

[MoFo]

I'm sure the VB drivers are doing what their company tells them to do. The issue is, do the company honchos believe that you can't save fuel at lower flight levels into a headwind.

Under circumstances where you can gain a substantial increase in ground speed your time in the air is much less. You save fuel even though the fuel flow is higher. This ain't rocket science. They'e been doing it since jet airliners were invented. The original TAA B727 drivers who were ex WW2 were doing it in Australia in the 60's and believe me it worked.

However its VB's toy set and they will operate it how they see fit.

As time goes on someone always thinks they've re invented the wheel.

[Dehavillanddriver]

I spoke with my "consultant" about the responses above and he confirms that what DJ do is correct in wind conditions where there isn't a huge gradient.

Where the huge gradient exists it is sometimes better to go down, but as the flight plan is calculated on a fixed cost index, the lower you go the slower you go, negating the benefits to a certain extent.

The fix is to run variable cost index plans, and this apparantly is in the works, but there is some re-arranging of the deck chairs and that may take some time to organise because of technical issues with the flight planning computer

In strong winds , particularly with big gradients, it is better to go low, but because of the high proportion that fuel makes up of the total operating cost of the VB fleet, it isn't always obvious which is economically better - the fuel makes up a far larger proportion of the variable operating cost of the aeroplane than most people realise.

Because of this it was decided to have a policy of flying the plan as indicated and accept that on some occasions you are on the losing side of the cost equation - swings and round abouts my contact tells me.

3 bars, using your example of 8-9 minutes for say 200 - 300 kg, under the VB system it would probably be better to stay high, because the cost of that 200 - 300 kg is supposedly more than the cost of the aeroplane maintenance.

This of course completely disregards schedule integrity and other commercial issues.

Amos - thanks for you constructive remarks - I reckon I have got a pretty good grip on how things work.

Borg thanks for the info - the big difference between the two organisations will be the financing of the aeroplanes - that will alter the importance of the cost of fuel in the grand scheme of things

As for ATC putting VB first - I think that if you spoke with QF drivers that would say that VB get preference all the time, if you spoke with VB drivers they would say QF got preference all the time - it is all perception I guess!

[qfpaypacket]

Her's a thought .... They probably fly high despite unfavourable conditions because the bloke in the left seats probably got one year on 737 and the f/o's probably got 1000hrs total - and they're just sooo excited. (sorry to the ex dispute guys, they are different, but in the minority by far.)

[amos2]

Ok! Kiddies, now listen up! (especially our junior flyers SB and VBC)...we will do some basic (PPL) Flight Planning.

Q1. If there is a strong headwind up high and a light wind down low should a pilot fly his aeroplane...

(a) Inverted.
(b) Backwards.
(c) At the lower level.

Now I know this sounds like a trick question, but think about it!

Next week we shall study some basic (PPL) Aerodynamics, such as...

If a pilot wants his aeroplane to go up, should he...

(1) Push the stick down.
(2) Push the stick sideways.
(3) Pull the stick back.

Always remember the basic rules...

(1) RTFQ.
(2) Your first answer is probably the right answer.

The following week we shall move onto advanced (CPL) Aerodynamics and explain how a pilot can make his aeroplane go down! This will be exciting, believe me!

[silverforky]

I feel that the VB aeroplanes belong to VB and they should be flown as VB request.
The QF aeroplanes belong to QF and they should be flown as QF request.
Why bother with the discussion - boys!

[Dehavillanddriver]

Ok Amos - here is one for you

If the company tells me to fly the aeroplane in accordance with the flight plan because it is normally more efficient I would:

(a) Fly the aeroplane in accordance with the published company procedures
(b) Fly the aeroplane the contrary to the flight plan because I know better
(c) Don't know because I don't actually fly aeroplanes, I just like making myself feel better by making ******** comments

[GT-R]

I think you've just summed yourself up there Dehavillanddriver. That question you have asked and the answer you truly believe to be correct is quite astonishing.

You sound like an absolute clueball.


White aeroplanes steaming past at a great rate of knots, and the fuel burn must be horrendous

Perhaps you should have a look at your Performance Manual, thats that bunch of paper wrapped in plastic inside a plastic folder, use pen to break the plastic so you can read it.

Have a look at the difference in fuel burns at different levels.

Also, have you heard of break even wind trade?

Perhaps you should have a read of that if common sense doesn't prevail.

C) Fly the aeroplane the contrary to the flight plan because I know better

Of course we know better, its called airmanship vs. a flight planner and a computer program, you know, like carrying a TEMPO to a destination when arriving 2 minutes before the TEMPO period.

You aren't flying a sim, though I wish you were with a knowledge base and 'follow the flightplan' attitude like that.

Oh yeah, and next time you depart in front of another aeroplane, try using some airmanship and don't climb at 270kts because you lot are about the only airline in the world who operate so friggin stupidly.

[Next Generation]

Geez!

You Q@NT@S guys are so sensitive.

Taking a lot of things personally aren't we ?

Of course you guys are the best. You have had so much sunshine blown up your collective @rses that you now believe that you are the only blokes who know how to fly. You even know better than Boeing how your machines should be flown !!!

Now can the rest of us who genuinely want to discuss this topic objectively please get on with it.

Thankyou.

[Kaptin M]

Ooops, sorry. I thought that this was the professional pilots' forum!

Fly the thing the way the Company tells you to.
It's their train set.

If they WANT you to start using your skills for the areas in which you've been trained, it should be emphasised that the flight planned levels are recommended only, based on the latest FORECAST winds, weights, and other conditions at pre-flight.
If they don't, just be happy to be a "glorified bus driver"...fat, dumb, and happy....and collect your pay packet every couple of weeks.

Remember the "good ol' days", Amos when the crew used to do the flight planning "long hand" - selecting optimum CRZ levels, calculating individual burn-offs for climb, cruise & descent - working out TOD's based on weight at TOD, headwind/tailwind, ISA +/- ???

Ahhh, you youngsters don't know how easy you've got it in these new fangled machines. It's interesting to see some of these guys (I fly with) pulling speedbrake, or putting power on, based on incorrect FMC readouts at times!

[amos2]

So, NG, as I gather you are still seeking the answer to the question could I suggest you have a close look at answer (c) question 1.

[ferris]

I used to sit there and watch the 2 schools of thought: QF down low, grounding out a lot faster, but obviously at an inefficient level, and his pidgeon pair up high, at least a hundred knots slower, but at "optimum" level, wondering if the trade-off of the longer time in the air for the more efficient fuel burn was worth it.
After reading this thread so far, I'm none the wiser.

(we always assumed that the fuel equation was irrelevent, as the drivers up high were payed by the minute, and QF were paid by the sector- tell me I'm wrong:cool: )

[slice]

GT-R I presume you mean 2 minutes before the TEMPO 30 minute buffer period. :E

[Keg]

Hey NG, this thread started out with a QF bloke asking about VB. Just because some others have leaped on and created havoc, don't assume that they are necessarily QF drivers. The question could so easily have been asked by VB drivers as to why QF crews go so fast and so low and the responses from the QF crews would have been sensible.

Shame to see yet another possibly useful thread on each others operating philosophy degenerate into name calling, derision and one upmanship with a side of venom. :(

Dhd and the other 'normal' VB crew, thanks for your input. 'Interesting' but thanks all the same! :D

Regards,
Keg

[Next Generation]

The question could so easily have been asked by VB drivers as to why QF crews go so fast and so low and the responses from the QF crews would have been sensible.

KEG,
I agree with you. I am just interested in the subject matter and I don't care who started the thread. It is an interesting subject, which appears to have gone off the rails due to some people having a "Superiority Complex".

I wish those who have the knowledge could share it in a constructive way.

[Dehavillanddriver]

On each occasion, a fair proportion of the supposedly "experienced" airline pilots such as our learned friend Amos and GT-R, have missed the real point

The point is that unless you know the real COST of operating your aeroplanes, you DON'T know if it is more ECONOMICAL to cruise higher or lower.

For a fixed fuel price...

If your maintenance costs on a dollar per flight hour are higher, the extra burn down lower is worthwhile

If your maintenance costs per flight hour are lower, the extra burn down lower may NOT be worthwhile

Now Amos and GT-R you can make smart remarks about opening performance manuals etc, but riddle me this....

If it costs company Q say $0.83 per minute per minute and it costs company V say $0.50 per minute - of which fuel and maintenance make up a significant proportion (disregarding lease, crew, and other fixed costs) and both charge roughly the same fair, and Company Q gives away free "food" etc.

Which one is going to be making cost reductions?

I know here is an idea! - lets not worry about how much it costs to run our aeroplanes, lets run them around at low level burning heaps of fuel, we can make our savings in crew costs by getting a NZ subsidiary - lets call them "Q connect" to do the flying - we only need to pay those "glorified" bus drivers 50% of what we are paying Amos and GT-R.

MMMMM - wouldn't it be better for all of us if we used our machines more efficiently, realising savings that are there for the taking if we care to look, rather than throwing the baby out with the bath water?

I admit that the policy we have at the moment isn't ideal, but under the circumstances it works. It can (and will eventually) be improved, but for the moment, given the internal resources, it works fine.

Have any of you ever considered that by running around super fast you are just encouraging commercial to further tighten already tight schedules?

Just out of interest, on the 737, what DOES QF say about cruise speeds and levels?

[Next Generation]

DHD

Thank you for your useful post.

There is obviously much more to the reasons that each airline does what it does.

[Dehavillanddriver]

Oh and GT-R while we are at it....

Oh yeah, and next time you depart in front of another aeroplane, try using some airmanship and don't climb at 270kts because you lot are about the only airline in the world who operate so friggin stupidly.

We are just operating our aeroplane in accordance with our company procedures - just as you are with the speed restrictions below 5000 etc.

No need to suggest that people are NOT using airmanship.

[Keg]

Dhd, I think the point that TCOB was making is that often, going low will have a neglible effect on fuel (break even wind) and the a/c will be in the air for a lessor amount of time meaning less maintenance. i do agree about knowing all the costs and admit that I DON'T know them but aren't we employed to fly aircraft safely, comfortably, to the schedule, and then efficiently (all things considered and within reason for the last two of course!).

Anyway, on another thing, are you saying that the company gives you no discretion on what climb speed to fly? We get no discretion on descent below 5000' but on climb it is dealers choice and comes back to the other priorities that I listed above. Not having a dig. Genuinelly want to know.

Finally, is GT-R with QF?

[rockarpee]

Gday Keg, GT-R would have to be part of the QF training??? system;) ,such a sensitive touch in his way of imparting knowledge:rolleyes:

[oicur12]

And heres my 2 cents,

QF have a large network with A/C flying integrated patterns that VB do not have to be concerned with.

QF procedures may dictate that although the A/C departed on time (eg syd - per) , it also has to fly lower and faster to arrive on time in order for pax to meet connections on same airline to further destinations.

VB can depart on time - keep the on time record intact, fly at econ, saving fuel costs, and arrive late where pax are not doing tight connections to other destinations.

Both are probably appropriate operating techniques for very different requirments.

My (rather crappy) airline has no integrated patterns and no need to arrive on time - only departing on time counts.

[clear to land]

As far as climb out with VB goes: All take offs are a noise abatement profile ie acceleration at 3000 AGL. Climb speed then in accordance with SID if applicable, else usually what the FMC recommends. If rough, then (shock,horror) airmanship prevails and max rate used until smooth again. If you get away real late you may climb at 320 into appropriate Mach No., as the Captain sees fit.
Descent profile is normally FMC determined Mach No. into 300, then as per STAR/airspace limit. If high speed required usually M0.8 into 320. Deceleration is at the crews discretion, then only criteria being Stabilised as per Boeing FCTM standards by 500 ft VMC or 1000ft IMC. Company prefers us to select flap stages within 20 KIAS of next Lowest limit.:8

[amos2]

Ok! Kiddies now listen up!(not you Keg, you can go to the top of the class).

1. Safety
2. Comfort
3. Schedule
4. Economy

Didn't some of you blokes ever learn the basics like keg and one or two others?

So, let's review basic Flight Planning/Performance...

If a pilot can fly his aeroplane from A to B at a low level, in a light wind, with an equivalent fuel burn to that of a higher level and arrive on time...

OR

Fly his aeroplane at a high level, in a strong headwind, with an equivalent fuel burn to that of a lower level and arrive 30mins late...he should...

1. Fly at the low level.
2. Fly at the high level.
3. Have a discussion on 'Prune cause he doesn't know.

[The_Cutest_of_Borg]

Yes it is disappointing to see the PPrune al-Queda cell hijack yet another thread.

What started as a civil question and some civil replies went seriously and needlessly astray there.

To the VB pilots who took the time to answer, thank you.

GT-R, if you are a QF pilot, you do the cause of some of us, who are trying to undo the negative image of QF pilots in this forum, absolutely no good at all.

[Dehavillanddriver]

Amos,

If you are capable of reading, go and review all of my posts, and you will see that we are in heated agreement.

Where we disagree I suspect is the meaning of the word "equivalent"in your last post.

If in your last post you said "the same burn" I would agree.

Where I disagree is that I don't believe that the average line driver, who DOESN'T know the cost of maintenance and fuel can make an informed judgement about the cost of staying higher versus the cost of the fuel for going lower.

The old chestnut "it is only a couple of hundred kilos" doesn't cut it - as in some cases that "couple of hundred kilos" costs more dollars than the maintenance time that they saved - that is the entire point of all my posts.

In the absense of the information I need to make an informed decision I generally follow the policy of my EMPLOYER - the people I MAKE MONEY FOR.

Bear in mind this whole discussion is about pure $ cost for a particular flight, not all the attendant commercial issues.

Finally, the other point you seem to miss is that the VB high QF low thing is an all year round thing, not limited to strong jetstreams or east/west flights. I have seen QF aeroplanes up to 15000 ft lower when there has only been 20 knots between the two levels in terms of wind.

it isn't personal, it isn't bad airmanship - it is company policy.

Do you hate wearing your hat and tie - but do so because it is company policy? - there is no difference!

[Spotlight]

Sorry Amos, but your secret is not as secret as the real secret. Only the anointed keepers of the secret can understand real efficiancy.

And the beauty of working with pilots is that pilots never age, the same carrot works every time. And it always is: the same carrot.

[Dexter]

how hevvy is the pilot amos?
and is the 2 air plans the same type?

[rockarpee]

ok gotta ask . who the hell is AMOS2? obviously knows "mechanics of flight" backwards but has know idea about a little chat forum, AMOS, just a bunch of guys/gals shooting the breeze. F :mad: ck off

[Spotlight]

Need I say more!

[blat]

AMOS2? obviously knows "mechanics of flight" backwards HAHAHAHAHAAAAAAAAA....! ! ! !

No he doesn't, he's quoting something any student pilot would know about fuel burn to try and get some attention because everyone's ignoring him. What a joke.

At least when the Kaptin (his benign defender) makes a comment you can tell he's at least thought about it. Amos2 reminds me of that bonehead in "Of Mice and Men". You know, the dumb one.

To use amos2's own words:

SOD OFF.

[Kaptin M]

A couple of Q's for some of you.
When fiddling with the FMC:
Do you know the difference between Optimum Cruise Level (CRZ page), and Trip Level (Perf page)? Is there a always a difference? If so, why?

Do you ever enter ACTUAL reported wind at a different FL, and check the Step to?
If you could save fuel from doing the above, how many minutes minimum must you spend at a higher level to justify climb, before reaching TOD?

Approximately how much fuel is lost/saved per minute difference to original FMC calculated ETA, by speeding up/slowing down?

[Keg]

DHD, that 20 knots difference in wind when QF is (say) 15,000 feet lower translates into about a sixty knot+ difference in ground speed due to higher TAS @ FL280 (depending on the day of course!). As you would have read in the newspapers, schedule is a pretty big issue at QF these days and so saving 5 minutes on a SYD-MEL leg can influence things over the period of the day.

[rockarpee]

Further to Kegs note, QF 's unofficial line on the east coast sectors would basically be "hang the expence" grab that extra coupla minutes where possible. It is not uncommon even during times of nil Jetstream activity to see qf jets at the lower levels just to make up time etc...

[Dehavillanddriver]

Hi guys,

this is where the two companies differ in their operating philosophies.

As you say QF is hang the expense.

VB take the opposite view and cruise a little slower/higher, but make it up (to a certain extent) by scheduling 30 minute turns not 35/45

I guess at the end of the day it all works out in the wash

But as some of us seem to forget, we basically do as our masters command - not because we like it or agree with all the time, but because they pay the bills and it at the end of the day is their train set.

Apart from the obvious, it was a good thread!

[Suffering Sucataash]

After all the science has been considered, I think you have to really consider the history of the two pilot groups. At QF we are paid by the sector and many VB Captains still have the Ansett legacy of had being paid by the minute, habits can be hard to break expecially in pilots.

Clear to Land

As an aside, consider the wisdom of a 320 kts climb if you are late. It may be faster to climb slower and get into a tailwind. I prefer to trust the FMC a little more for optimum climb speed, if you are late just bump up the Cost Index, I also put limits on Performance page 2.