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-   -   Jetstar deferring 787 deliveries? (https://www.pprune.org/australia-new-zealand-pacific/540866-jetstar-deferring-787-deliveries.html)

Troo believer 6th Jun 2014 02:33

All well and good but what about the engine out gradient and the obstacles? Currumbin Hill? Its got nothing to do with the distance to Narita but all to do with the grunt using a smallish runway with obstacle limitations. 1.2% nett gradient engine out second segment limit. Maggotdriver is correct, its limiting and thats why the first 4 787-8 are orphans. They were ordered by Dixon to be domestic 767 replacements in 2008. The rest is history. Good to see J* international looses money now that mummy doesn't pay the fuel bills. Thanks Nic for exposing this charade.

FYSTI 6th Jun 2014 02:41

...and ISA+20, and occasionally +25.

Mstr Caution 6th Jun 2014 08:32

Troo Believer.

All will be OK, as JQ are working on OOL schedules to depart on days where there are strong South Easterly Winds.

toolish 6th Jun 2014 09:29

Or depart from the Brisbane

Normasars 6th Jun 2014 11:13

Maggot,

I don't need to take a bex and lie down at all; quite the contrary!!

I saw the writing on the wall and exited stage left a few years ago now. I'm not the one self destructing.

You guys on the other hand .............

flyingins 6th Jun 2014 11:48

Maggot et al,
I can't speak to anything other than common knowledge on the line, but all JQ 788s are 63.8k engines. Always have been. (as moutere101 says, the lowest thrust rating GE offers on this engine is in the low-to-mid 50s!)

I doubt your mate told you a porky, but really the rumours going around on this forum and down at the Coogee Bay Hotel have confused everyone.

Out of interest VKA was delivered with two different version GEnX engines and since that delivery the older one has been swapped out for the latest version. All others have the latest version on both sides. All are and always were 63.8k.

As for OOL on a summer's day, I understand that the answer is yes. I am sure that the A330 would have wider performance and environmental margins, to be fair, but presently JQ is running one of the highest ZFW, lowest thrust setting combination 788s in the world and it's still meeting/ beating performance forecasts. Boring for pilots, exciting for accountants.

WRT to climb gradients at OOL, I too had heard the issue was originally terrain off the end of 32 more than any other. Now that the type has settled further into service I've heard that the refined numbers have been run again and it fits. I have no idea about future changes to thrust settings. Above my pay-grade.

Allegedly.

moutere101 6th Jun 2014 13:06

JQ 788
 
Troo Believer..

This is what Piano-X is saying..

TAKEOFF PERFORMANCE {198000.kg., altitude 0.feet, ISA+12.deg.C.}___________________
** WARNING: Takeoff flap was reduced to 14.1 degrees
in order to meet the minimum 2nd segment gradient
JAR25 Takeoff Field Length 8109. feet
115% Factored All-Eng.Dist. 7723. feet
Balanced Field Length 8109. feet
2nd Segment Climb Gradient 2.40 %
Takeoff CLmax 1.92 {wimpress ref.area}
Takeoff Vstall 131. keas
Takeoff Vmc 124. keas
Takeoff Vfail 147. keas
Takeoff V2 151. keas
L/D at 2nd segment 12.66 {incl.windmill & asymm.}
Takeoff Static Thrust 258442. newtons per engine
Takeoff Thrust/Weight 0.266 available static
Takeoff Wing Loading 5387. n/sq.m.{W/S wimpress}

moutere101 6th Jun 2014 13:15

JQ788
 
So if the engines are ~64K then the MTOW out of OOL is ~218t
and you get something like this.

AKEOFF PERFORMANCE {218000.kg., altitude 0.feet, ISA+12.deg.C.}
___________________

JAR25 Takeoff Field Length 8088. feet

115% Factored All-Eng.Dist. 7673. feet
Balanced Field Length 8088. feet

2nd Segment Climb Gradient 2.99 %

Takeoff CLmax 1.94 {wimpress ref.area}
Takeoff Vstall 137. keas
Takeoff Vmc 135. keas
Takeoff Vfail 152. keas
Takeoff V2 158. keas
L/D at 2nd segment 12.26 {incl.windmill & asymm.}

Takeoff Static Thrust 311376. newtons per engine
Takeoff Thrust/Weight 0.291 available static
Takeoff Wing Loading 5931. n/sq.m.{W/S wimpress}

waren9 6th Jun 2014 15:38

what sort of range is that then? cheers

moutere101 6th Jun 2014 16:41

JQ788
 
Warren........

about 5600nm/ 11.5 hrs

FYSTI 6th Jun 2014 20:24

moutere101, what MTOW / range do you get for:
  • ISA+15
  • ISA+20
  • ISA+25 (rare)
They are the realistic possible temps for six months of the year.

moutere101 6th Jun 2014 23:39

JQ 788
 
FYSTI............

ISA +15 217t 8084ft 711min. 5583nm

ISA +20 211.75t 8095ft 658min 5157nm

ISA +25 205.5t 8103ft 605min 4721nm

The time is block time.

Is there anyone out there who is privy to the OEW's JQ's 788's , better still does anyone have a typical DOW or known by some as Runway OEW.

Popgun 7th Jun 2014 01:47

Operating Weight
 
Exact weight varies by airframe.

Basic Weight approx = 114.0

Operating Weight (incl crew 2/9) approx = 117.0

PG

moutere101 7th Jun 2014 02:20

JQ 788
 
Thanks Popgun ,this OEW tracks real close to QR's.

re engines, the CASA register shows VKA and VKD with GENx-1B64's and B,E,F,G and H with -1B64/P2G01. GE quote both engines at 298Kn take off thrust. I make that to be around 67000 pounds so I don't see them as being short on power. Piano-X uses the EIS value which I believe was 64K pounds.

Based on Popguns values and the 67k thrust the OOL numbers look something like this.

ISA +15 220t 7991ft 6021nm 764min
ISA +20 215t 8024ft 5622nm 715min
ISA +20 210t 8059ft 5200nm 664min

As usual E & OE :)

Beer Baron 7th Jun 2014 15:22

Piano-X isn't exactly official performance data. Anyone got the real figures from their operators performance manual/OPT?

redkite1 7th Jun 2014 17:01

Jetstar deferring 787 deliveries? - Lets not get caught up in dazzling facts about aircraft performance and wing loadings - lets stick to gritty rumours here. I think the guts of the argument is not about the struts, it's about QANTAS is out of CASH!!! Get it, Jetstar is a shelf company and it's parent QANTAS pays the bills and is now broke!! If QANTAS had the money it would snap up the new airframes whatever strut/engine combo it has, gift them to Jetstar and find any number of routes to fly it on. The question is - how broke is the kangaroo??

OK, Jetstar isn't a shelf company.....

griffin one 7th Jun 2014 19:15

who cares? QF is lost ,Jstar 787 will rule the world according to alain and the poor 744 pilots are believing in Marty Mc fly and his Delorean.

Wake up and smell the avgas.Jstar is growing,QF shrinking,and the LCC model will last about five years more,who invest $230 million an airframe to sell seats at $69.

better return with money in the bank

redkite1 7th Jun 2014 20:23

Griffin One, Jetstar aint expanding anywhere if QANTAS is broke and the whole house of cards falls down... QANTAS group = Jetstar + mainline + the board + hundreds of other entities. Lots of tribal battles going on in there but your 744 and 787 crews are all part of the one group and are employed by one and the same board.

It is very easy to interchange the names QANTAS/QANTAS group/Jetstar and make it mean what you want it to mean, which is what Joyce and Dixon have done for years to camouflage their real agendas. So the question I am making is this: is it 'Jetstar' delaying deliveries for 'performance shortfalls' or is the Qantas group broke and can't afford them - I know which one I would lean towards right now.

qfpaypacket 7th Jun 2014 21:26

Had dinner with a consultant who had been involved with Qantas restructure. He said that once the grand plan had been rolled out and the long haul award was extinguished, the plan was to magically come up with a plan to equip Jetstar with 25 B787 to fly in both silver and red tails.

This isn't about pilots, it's about awards. Including the l/H flight attendants and engineers. There is a reason J* is working so hard on introducing the new 787. Their pilot award is 25% more efficient. Their F/A award is 66% more efficient etc etc

This guy would know, they are the guys steering the industrial ship in the background. It's what they are paid a lot on money to do.

Popgun 8th Jun 2014 01:31

3 airframes were delayed to July/August, apparently so that for accounting purposes the costs were pushed into the 2014/15 financial year.

Those airframes start arriving in a few weeks.

The additional pilots needed to fly them are currently completing their type ratings.

The only 'deferrals' are the already announced 3 airframes - so 11 total instead of 14. That is a 1 for 1 swap out with the A330s returning to QF.

Strong rumours fuelled by management comments are that those 3 airframes will be 'un-deferred' once it is politically expedient to do so.

PG


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