Australian Airlines Slow down to save fuel

[9v-SKA]

Australian airlines slow down to save fuel http://www.straitstimes.com/STI/STIMEDIA/image/20080523/ST888413101_01_0001.jpg
http://www.straitstimes.com/STI/STIMEDIA/common/c.gif
Qantas (above), one of the world's major airlines, which dwarfs Jetstar's annual fuel consumption of 580 million litres a year, issued a terse statement on which it would not elaborate. -- PHOTO: AP
http://www.straitstimes.com/STI/STIMEDIA/common/c.gif
SYDNEY - SOME Australian airlines are flying slowly to save fuel as oil prices surge to record highs, it was revealed on Friday. Like motorists trying to economise, pilots are easing back on the throttle, national carrier Qantas and its budget offshoot Jetstar said.
Dropping the average flying speed on their Airbus A320s by about 20 kilometres per hour would save millions of dollars a year, Jetstar spokesman Mr Simon Westaway said.
'We are conducting a trial of flying the aircraft at slightly lower airspeeds,' he said.
Airlines have a cost index from 0-99, in which '99 is what is usually simply called putting your foot to the floor - that's essentially maximum fuel burn.
'Zero is the minimum, so its essentially how you ride the accelerator,' he said.
Jetstar was testing dropping its cost index from 30 to 10 as the price of aviation fuel soars along with oil, which hit all-time highs of more than US$135 a barrel this week.
'Essentially it means a reduction in speed of around 10 knots or 20 kilometres an hour over the course of a journey.' The slower speeds would add about six minutes to a trans-Australia flight from Melbourne to Perth, which normally takes between three-and-a-half to four hours depending on direction and other factors, Mr Westaway said.
The extra few minutes do not appear to have raised the ire of passengers, who probably have not noticed among all the factors that can slow a journey, from delays ahead of takeoff to circling before getting the go-ahead to land.
On long-haul flights, those minutes would multiply and mark a strange reversal of the ambition for ever-faster connections around the world since the invention of flying.
But with oil supplies finite and price rises appearing limitless, jet pilots driving like cash-strapped commuters appear to be a sign of the times.
Qantas, one of the world's major airlines, which dwarfs Jetstar's annual fuel consumption of 580 million litres a year, issued a terse statement on which it would not elaborate.
'Qantas has used variable speed flight plans within its schedules over the last two years as a fuel conservation initiative.
'This practice has led to fuel savings and lower carbon emissions without any significant impact on flight times.' Qantas announced Thursday that it would increase international air fares to counter the impact of rising fuel costs by about 4.0 per cent from June 4, after a 3.0 per cent hike earlier this month. -- AFP



Source: Straitstimes.com.sg

[Taildragger67]

Time to dust off thoughts of getting towed out?

Actually, would there be any saving in starting one (or two, in a 3- or 4-holer) at push-back and then firing up the remainder closer to take-off?

Or, setting take-off sequence when a/c are still on the stand and only giving taki clearance when it's likely that the departures won't have to queue for ages (or at least dispersing around the field to free-up stands - I have in mind KJFK and the 60-min-plus evening rush waits, probably more than Australian fields)?

That is, it seems to me to be folly to give taxi clearance to, say, five departures in five minutes when there is at least a 1-min gap between take-offs; if all taxi out in a line, you are straight away looking at a 10-min delay for the last one off.

[Keg]

i only ever went to JFK once but i think QF was looking at a procedure to shut one down on the taxi out and restart (obviously) a bit later due to the extended delays always experienced there. Shutting one down on the 744 for taxi in has been around for quite some time....if anyone remembered to do it! :O

It's probably not worth the hassle for the very occasional extended ground delay post pushback in Australia.

Tow out on the other hand is an idea that has been thrown around previously. I'm sure there is a cross over point at which the economics of it start to look good. i wonder where that point is. Ironic that the guy who tows the aircraft out gets paid a ****e load more than a VAustralia 'Cruise F/O'. :eek: :E

[Flight Detent]

Cruise flight speed schedules have been based on airplane weight for long distance flights since the B707 was in service!
That is, the heavier the AUW, the faster the cruise speed, and vice versa. The result being that as the airplane used up fuel, the cruise speed schedule decreased, effectively maintaining a constant wing angle of attack, the designed cruise AOA.

Only a small decrease (or increase) in this designed speed for weight can be tolerated, after which drag increases, forcing up the power/fuel required to maintain that speed.

Much better to move the CG aft in cruise, and maintain the design cruise speed.

Engine manufacturers recommend minimum engine operating times prior to takeoff power being applied, and indicate that higher peak EGT will be incurred when the warmup time is lower. Now isn't that totally contrary to the whole reasoning for using derated/reduced power settings when you can, to lower that peak EGT and extend the service life of the engine!!
The warmup time is around three minutes at or near idle for most engines!

Anyway, if the Airbus went any slower, they will have to start celebrating birthday parties on longer trips, and quoting the arrival time by the date.

Cheers...FD...:bored:

[ULH Extreme]

We do that now on the A345 LAX and EWR flts:ok:

[Spotlight]

Go hard into the headwind. Back off in the tailwind. Has some come up with a better idea?

[veloo maniam]

Your MNT(Mach No will be less). I will keep u at a lower level
and give the faster guys the higher levels or the optimum levels.
As a Ctler I do not want u to hog a good level.
What will be the MNT if you are going to fly slow?
I observe that JSA always does a slow climb.Why is this so?
Replies appreciated.:ok:

[amberale]

If you guys/gals are going to do an economy[slower] cruise/descent please let the controller know early.
The flow is looking at the sequence from around 250 miles out and it is usually set by 200 miles.
An econ cruise descent can cost 2-3 minutes at the 40mile gate and this can create a hole in the sequence and concertina the following traffic.
If the flow doesn't discover this until you are at 150 miles then it can be too late to fix.
Worse, you may be instructed to increase speed thereby burning the fuel you saved.
If we know early then you might drop back one in the sequence and land at the same time but 10 following aircraft might save 2-3 minutes each.
Just tell the controller "for the flow we are doing econ descent 250kts".:ok:

AA

[dodgybrothers]

amberale,

with respect, its not upto us to let you know, the company should have already done this. If they havent then you should place an incident report as they are not compliant with the speed schedule as submitted to ASA for standardisation. I have a problem with the company altering speed schedules without atc knowledge as I am sympathetic to your problem. But we fly the aircraft the way the company tells us to. In other words, its not our fault.

[Eastwest Loco]

This is most likely a dumb question, but on heavily loaded flights at upper altitudes are we not taking a chance of pushing into "coffin corner" and risking a high altitude stall?

As I said, probably a dumb question but do recall several American carriers getting 727s into such stall conditions and doing significant damage to moveable control surfaces rescuing the beast.

The paperwork - Ooooh the paperwork!!

Best all

EWL

[Chimbu chuckles]

The flow is looking at the sequence from around 250 miles out and it is usually set by 200 miles.

amberale that aint how it seems arriving at YSSY at 0600:E

And as for YPPH:(

Dubai? One controller wants you at barber pole and the next wants you at min clean, if not min approach:{

[HF3000]

For Christx sake, noone is going to be cruising in coffin corner and noone is going to be descending at any other speed than that agreed between the Company and the ATC authorities. End of story.

It's a slight adjustment to cost index. ATCs didn't have any clue as to what CI was applied previously and they don't need to know the new one either.

It's nothing.

[Blip]

dodgybrothers I gotta say I don't understand the point you are trying to make.

amberale,

with respect, its not upto us to let you know, the company should have already done this. If they havent then you should place an incident report as they are not compliant with the speed schedule as submitted to ASA for standardisation. I have a problem with the company altering speed schedules without atc knowledge as I am sympathetic to your problem. But we fly the aircraft the way the company tells us to. In other words, its not our fault.

You turn up for work and are presented with a flight plan. The flight plan tells you what cost index it is based on. The Mach number that results from this chosen cost index is submitted to ATC with the rest of the required flight plan details. Somewhere on the flight plan will be a copy of these details, including the Mach number.

It is this mach number that ATC use to estimate you eta at various points along your route.

I think the point that was being made was that if your flight plan uses CI 40 and you decide to fly at CI 0 (zero) because you are running early and decide to save some fuel, ATC want to know what your revised Mach number is so that they can factor it in when working out the traffic flow.

The flight plan may have indicated that you were going to cruise at M.80 but after entering CI 0 (zero) into the FMC you slow down to cruise at M.77. That is a problem for ATC. That was the point being made.

[Jabawocky]

It's nothing.

well.......... Drive it like ya stole it!:}

Talking to one Airbus Captain today he wondered if it really saved money, might save some fuel, 100kg here and there, but how does the cost of longer engine / airframe hours, wages and other flow on effects add up?

Maybe cheaper to stick it to her!

J:ok:

[Stationair8]

In a four engine jet why not shut an engine down in the cruise?

[Blip]

Talking to one Airbus Captain today he wondered if it really saved money, might save some fuel, 100kg here and there, but how does the cost of longer engine / airframe hours, wages and other flow on effects add up?

That is exactly what Cost Index is all about! Cost of fuel vs cost of time. Somewhere between flying at minimum fuel burn/ max range speed, and min time speed is a compromise between the two that gives overall min COST speed.

As fuel becomes more expensive, min COST speed moves towards min fuel burn speed, ie better to use a lower Cost Index. Ah but which cost index to use? That is the question to be worked out by the "experts" in your company's flight dispatch dept.

[Triple Captain]

I did hear a Jet* flight day before yesterday requesting a .77 cruse into YMLT i beileve.

[haughtney1]

My company (UK based) on the 757 and 767 is currently using a cost index of 18.
Gives a .78 still air cuise on the 757 and .785 on the 767. At current prices it will save 650,000 USD per airframe on average this year.
It adds around 12 minutes to a London-Vancouver sector, and about 8 minutes London-New York.
More flight duty pay though:E

[amberale]

Dodgyb,
all we get from your FP at the console is an IAS [yep, 400-450kts]
The flow calculates your feeder fix time[40nm] using real data[your speed and known winds] and adds a known time from that point to the threshold.

That time is then used to establish the sequence order.

The speed schedule that the 3 majors in Oz have supplied us with is that you will fly fast if you are late, profile if you are on time and slowly if you are early.
We are to expect you to fly the same aircraft at different speeds at all times.:confused:
Chimbu,
unfortunately I don't think the SY flow starts before 6am.
We are trialling some long range stuff from the noc shop but some problems still exist.

Eclan,
sometimes the flow will group a series of flights from one direction and ask for them in trail, usually 10nm at 40nm from destination.
This equates to a 2 minute sequence and can save 30secs per flight.
If you are #2 and catching #1 at 50kt gs then the sector controller has to do something to maintain the spacing.speed or vector for extra miles.
Perhaps the preceding crew are operating in econ mode.

Disclaimer ; my details are for Brisbane flow but the speed problem [ie what speed are you going to do] is across the board.

I'm not accusing anyone of foul play, just trying to help us all.:)

AA

[fullforward]

Some interesting findings:

-on this aircraft, a recent study compared (real life, not software predictions) data colected from flights operated either on company suggested CIs, on the lower 30s, wich translates into an average M.83 crz speed with other operated on typically LRC, CI around 180, giving M.84.
Given comparable TOW, atmospheric conditions, routes and aircrafts the only difference in operating at the lower CI is EXTENDED FLIGHT TIME!

The practice contradicts Boeing software predictions. Flying at a CI lower than say 150-180 does not actually provide any significant fuel savings. On the other hand, keeping the cruise around M.84 saves time without burning more fuel, thus reducing the overal trip costs.

These are cold FACTS, not guessing, with enough data to provide a definite trend.

Any clues?

[Muff Hunter]

JQ has changed to cost index 10 with no change in the rostered block time, pilots are expected to follow this with no extra pay.....

[Zhaadum]

Man this is soo boring. Are you guys Pilots or Accountants? :confused:

You worked so hard to get to fly the big fast aircraft just to dawdle along like a Cessna? GO FULL SPEED and buggar the fuel! :ok:

[dodgybrothers]

amberale and blip,

The point I make, is that Jepp ATC 700 series 1.9.1 states that a speed variation on decent of + or - 10 kts or 0.025M must be advised to ATC as RPT Jet operators are 'supposed' to nominate a standard profile. If ATC ask me 'what is your decent speed' and I say 'Oh we're at CI 10' that means f@ck all to them. If my company alters a standard decent profile (like altering CI does) and does not advise ASA then they are at fault for not advising them.

We have no room to move wrt alterning CI, if thats what is nominated, then thats what they get unless we are advised by ATC to speed up or slow down or the company advises us to the contrary. Even if we are late, early or on time, the CI stays the same, there is no room to move. Thats is the point.

[stiffwing]

Amberale
I presume you mean TAS 400-450, not IAS.:eek:
Are you really privy to our schedules, how do you know if we're running late i.e. going fast?
Sydney flow starts well before 0600 LCL, enroute speeds can be adjusted by ATC as far out as 3 hrs to dest., which would be around 0300 LCL sydney time.

[clark y]

Another problem with going slower is that it's harder just to stay in CTA so we have to ride the speed brakes more, wasting precious energy. Not to mention inefficient altitude constraints and tracking, runway configurations that are set by the time of day as opposed to WX and traffic loads, company speed restrictions etc.
Going slower may save a bit of gas but there is a multitude of other factors that need to be addressed to create real savings.

[DeltaT]

The saving of fuel / slightly slower indicated speed comes in the cruise, not for example in the descent.
On a flight with a trip time of 3hrs we are only talking a difference of some 5 or so minutes (on the Tasman), and the flight planner will use the slower cost index for the flight plan if the computer shows for a 'normal' flight it will be ahead of schedule with the forecast winds i.e with the plane going slightly slower the punter will still arrive on schedule.
Non favourable winds, means the normal company CI is used.

Do not forget ATC see groundspeed on their radar not your indicated.

[cjam]

I think it's all small fry campared to the fuel wasted while holding and being vectored?
All too often a few hundred kg's of fuel is saved on a flight through judicious selection of crusing altitude, speed etc only to arrive and be put in a hold 50nm from destination.
CTA's (controlled times of arrival) are pretty much ignored by most pilots so the controllers just deal with whatever turns up on their screens the best they can.
I have to admit I don't pay much heed to CTA's , I don't see any point when I know most other pilots don't either.
I think that if CTA's were rigidly enforced then a lot of fuel/money could be saved. I think the rule should be that if you aren't within two minutes of your CTA then you hold until a gap opens up or you become fuel critcal. If it was that black and white pilots would know what to expect and could delay departure by a few minutes if a tail wind was forecast, or could call company and give an estimated ETA and recieve a revised CTA for a head wind. I don't think you would end up holding until reserves very often, most of the time a gap would open up pretty quickly but what it means is that the crews who meet their CTA's don't get dicked around, straight on in for them.
What do ya reckon? Am I dream'n?

[Keg]

I'm an Aussie pilot and I'll confirm that for the past couple of years we've been flying at whatever cost index gets us there on time. Often less than the 'standard' CI of 100 for the 744. Further, 767 domestic CI was once CI125 to meet quite unrealistic schedules. Now that the schedules have been paired back to something far more reasonable then CI40 is- from what I understand- far more the norm these days.

Further, the Straits times article was published after this article in the Australian a couple of weeks back.

[amberale]

Stiffwing,
Oops yes I checked today. Our copy of your FP shows TAS, usually 430- 455.
Lots of useful things we used to get are no longer available eg clias, pob..

Yes we are privy to your schedules via the CTMS and ATFM systems.
We and the airlines have access to these sysems and use them to assess peak traffic periods.
Unfortunately they are an overview system and not available to the flow at his workstation so, no, we don't know if you are late/early/on time when we are organising a sequence.
That's the problem. we don't know what speeds you are going to fly.
I say again Q, V and J have advised use in writing that while there is a standard profile they will vary it at will depending on their requirements.

The flow controller at SY does not start work much before 6am so far as I am aware.
Yes, long range sequencing is in action throughout the night to try to maximise runway use from 2000 utc and to stop 8 aircraft arriving at the same time and holding at 40 miles.
I think [but have been wrong on a semi regular basis] the nighttime flow is now done from the noc shop in canberra.

Come in to a center anytime and see how we try to do things. You will always be welcome. After all we are actually working for you. The aviation industry pay the bills and therefore our wages.

AA

[Blip]

dodgybrothers.

OK Although we vary the cost index and allow the FMC to command the resulting climb IAS/MN and cruise MN, we don't allow it to change the descent speed from those standard descent speeds that ATC expect from us +/- 10 kt.

I think we understand each other now:ok:

[VH-XXX]

Jetstar today announced that they are ditching the in-flight magazine because it's "too heavy"

[Gearupandorrf]

Maybe the Editors should be looking for some "lighter" content.

Sorry.
I just couldn't help myself.

[Zhaadum]

Elaine: "Would you like something to read?"
Lady: "Do you have something light?"
Elaine: "How about this leaflet? Famous Jewish sports legends".
Lady: "Thank you!" :}

Lady: "Nervous?"
Stryker: "Yes."
Lady: "First time?"
Stryker: "No, I've been nervous lots of times" :)

[willnotcomply]

The overall lack of tech awareness on this forum scares me.:uhoh:

[neville_nobody]

Wouldn't slower speeds reduce the utility of the aircraft? Or is fuel that expensive now it outstrips maintenance/leasing costs etc?

[Bedder believeit]

To Taildragger 67
Unfortunately you are looking at a fairly complex situation through (possibly) simple eyes. It would be all well and good if you just had 5 departures to go and then NOTHING, to do what you propose. Here in Hong Kong at certain times of the day we will have up to 20 aircraft requesting start and push back within a 5 to 10 minute period, with more continually adding on at the end. If we did as you say we would never reach the end of the queue. Add to that, with the complex departure slots that are placed on much of our traffic from our neighbours to the North the whole thing would end up a total mess....if it's not that already at times! As far as towing aircraft, that would be horrendous here, the grossly different towing speeds due to differing aircraft weights, the total loss of any flexibility in juggling departures, the strain (I would imagine) that towing heavily laden gross weight aircraft would place on the nose gear, plus other negatives. One also must consider that with aircraft taxiing on less than normal engine configurations, that increases in power settings needed to manouevre would cause possible damage to aircraft behind. The reason that these delays are with us, is not ..as many captains will say to their captive audience...ATC, but the fact that so many operators and authorities are trying to ring as much moisture out of the airport blood stone, as they possibly can. I have had the opportunity to watch and participate in, the movement of aircraft around airports for 40 years, and I can assure you, that what is being done at the moment is about as efficient as we can make it.
Aircraft have to be pushed back for departure to make way for inbounds needing the bay. I would say that in HK throughout the day, at least 5 to 10% of bays are occupied by late departures and not available immediately for an arrival, despite our having about 80 pax bays and another 40 freighter bays.
As far as JFK is concerned, they are just allowing far more aircraft to be scheduled during the "evening rush hour" than the airport or the airspace is capable of handling. My only advice to any departures is to get on the queue as soon as possible, and get outta Dodge.

[Taildragger67]

Bedder,

Thanks for the clarification.

[Bedder believeit]

Ta Dragger, hope I didn't sound too pompous. I guess we have about 200 towed events here in HK each day, aircraft being moved around from one place to another, and quite frankly, they are a pain in the arse. The tug drivers/operators don't speak English, so we (the controllers) have to give assistants in the tower the instructions for the tug/tow in English, then this is passed to the tug in cantonese on a discreet frequency, and then we keep our fingers crossed that the correct message has been passed and understood. The only exception is tug/tows that need to cross the South runway (07R/25L) then there must be an English speaking tug crew to receive the appropriate (runway crossing) clearance from the Aerodrome controller.
I think I know enough cantonese to understand what is being passed by the assintants, but the crews of aircraft taxiing around are pretty much in the dark as to what conflicting tows are doing.

[bekolblockage]

I think I know enough cantonese to understand what is being passed by the assintants

Can you give us your rendition of "big aeroplane" ? ;)

[Bedder believeit]

"Big-pella balus"....now that has you stuffed!

[drunkensailor]

I have seen a couple of QF 73NG's recently landing without the use of revese thrust. I wondered if this is one of the fuel saving measures they are trialing?