AIRBUS A 350 XWB

PARIS, 25 mars (Reuters) -

Qatar Airways n'a reçu aucune indication quant à un éventuel retard de l'Airbus A350 et est intéressée par une version actualisée de l'A320 de la filiale d'EADS , a déclaré jeudi Akbar Al Baker, le directeur général de la compagnie aérienne
qatari lors d'une conférence à Paris.

Qatar Airways fait partie des compagnies aériennes les plus dynamiques dans le monde et qui affichent des taux de
croissance élevés.
Le groupe a par exemple doublé sa flotte d'appareils sur les cinq dernières années.

Prié de dire s'il redoutait des retards dans les livraisons de l'A350 prévues pour 2013 à l'image des déboires qu'ont connus de 787 "Dreamliner" de Boeing ou l'A380 d'Airbus, Akbar Al Baker a répondu: "Non".

"Je pense que cela a été une fantastique courbe d'apprentissage (pour Airbus, ndlr)", a encore dit à Reuters le DG de Qatar Airways au sujet des problèmes rencontrés par Boeing sur le "Dreamliner".
"S'il y a un délai, ce sera juste de quelques mois, mais pas plus".

La compagnie aérienne qatarie est le principal client du futur Airbus A350 avec des commandes fermes portant sur 80 appareils.
Elle a également commandé trente appareils 787 "Dreamliner" et cinq Airbus A380.

(Tim Hepher et Lionel Laurent; Matthieu Protard pour le service français, édité par Danielle Rouquié)

Emirates Airline has asked Airbus to confirm that the Airbus A350 will still be on time for delivery.

Emirates has called on Airbus to give it more information on progress with the plane, after previous production delays.

The UAE airline is due to receive the first of 70 orders for the A350 in March 2014, but has said if they are not ready, it will rely on Airbus' rival, Boeing, to fill the gap.

It is believed Emirates is about to retire a lot of old planes and wants the A350 in service as quickly as possible to allow the retirement program to proceed.

The launch of the A350 has been extremely late, with customers like Emirates now asking questions about delivery promises.

• conception plus longue que prévue causant un glissement de trois du début de l'assembkage et du premier vol,
  
• utilisation de 5 avions pour les tests et donc concservation des délais de livraison
  
• gain de poinds sur la structure
  
• wingbox optimisée
  
• vitesse de croisière supérieure à celle prevue
  
• meilleure performance de déscellage
  
• etc.
  

Longer-than-anticipated design activities for the A350XWB twin widebody are forcing Airbus to delay the aircraft’s final assembly start and first flight by several months.
Nevertheless, the aircraft maker still plans to deliver the first A350-900 as scheduled in mid-2013.
“Three months of buffer have been used,” says A350 program chief Didier Evrard.
The three months were lost on a variety of efforts. One was to take more time to complete detailed finite element model work, fully refining the center wing box configuration, and to optimize fuselage damage tolerance. Extra work was also needed on the fuselage electric structural network.
Under the new schedule, final assembly starts at the end of the third quarter 2011, rather than the end of the second quarter, and first flight has slipped to the third quarter f 2012.
The time also allowed developers to conduct further analysis to shave weight from the total, says program chief engineer Gordon McConnell. On one structural element alone, that effort achieved 60 kg of weight reduction.
Most of the systems development remains on schedule, Evrard says.
The schedule adjustment compresses flight testing to 12 months from 15 months. Airbus will have five test aircraft to log about 2,600 flight test hours.
Meanwhile, wind tunnel testing and computer modeling show that long-range cruise speed is slightly above the Mach 0.85 target. Low-speed performance also has improved, with 475 ft. better takeoff performance and four metric tons higher takeoff weight performance in hot-and-high conditions, McConnell says.
Airbus also has launched a program to create some additional buffer in case it is needed.
There are no changes to the -800 and -1000 schedules, Evrard notes.
Airbus also has set up a special organization to work on the -1000, the largest member of the family. Its design freeze is planned next year. Evrard says the -1000 could feature technology upgrades since the selection was made for the lead version, the -900. Evrard says there are strategic decisions to be made on the -1000 that the personnel focused on birthing the -900 cannot address. Still, the 400 people will have close ties into the overall program to keep the A350 family concept alive, Evrard stresses.
Among the issues to be looked at might be whether composites could be used in parts of the landing gear.
The first Rolls-Royce TrentXWB engine to test is now in assembly for first run at the end of May. Seven engines are to run in the first six months. The TrentXWB will be airborne in the second quarter 2011 on the first A380 (MSN001).

[Vous devez être inscrit et connecté pour voir ce lien] launch customer [Vous devez être inscrit et connecté pour voir ce lien] is unconcerned about the three-month slip in the twinjet's first flight schedule, believing that the buffer built into the test programme should ensure its deliveries remain on track.

[Vous devez être inscrit et connecté pour voir ce lien] confirmed to a gathering of existing and potential customers in Nantes during its recent fifth-programme progress review that final assembly and the maiden flight of the first [Vous devez être inscrit et connecté pour voir ce lien] have slipped by three months to the third quarter of 2011 and mid-2012, respectively, due to issues that have cropped up during the design of the airframe's carbonfibre structure.
However Airbus remains committed to the mid-2013 first delivery to [Vous devez être inscrit et connecté pour voir ce lien], which has 80 of the [Vous devez être inscrit et connecté pour voir ce lien] XWB-powered twinjets on order.

"We are currently relaxed about the slippage," says the airline. "The three-month delay is easily accommodated within the flight-test timescale, which has been reduced from the very long 15 months originally planned, to 12 months, which is the industry norm."

The programme's chief engineer Gordon McConnell says the airframer knew it had "a good buffer" built in to the original 15-month flight-test programme and had been looking at ways to do it quicker.
Programme manager Didier Evrard says that as the detailed definition of the baseline [Vous devez être inscrit et connecté pour voir ce lien]-900 progressed last year and Airbus prepared to begin machining the first parts, "I had to give a bit more time to our structure designers for deeper validation".

He says that the reason for Airbus's caution was that the "process for development of structure in composite is really different [to metal] - you cannot start machining the part and then improve the design".

Four areas of the design were affected: the airframe sizing, the wing-root joint, the fuselage's electric structural network (which helps the conductivity of the carbonfibre fuselage) and the fuselage damage tolerance. The first two of these have been resolved and the fix approved, while the others have a solution under validation.
The slip has already had an impact on production, with the first material cut on the A350's horizontal cruciform sliding from November 2009 until 5 March this year, which has also pushed back the assembly of the centre wing box by three months to mid-2010.

Evrard says that the A350's systems development is "roughly" on schedule but having consumed margin on structures "it is important that we secure and find other buffers in the phases to come".
However, he is optimistic that the schedule can be met: "It's not going to be easy, but we have a good chance to be there or thereabouts."

[Vous devez être inscrit et connecté pour voir ce lien] is working to reach the design freeze for the largest [Vous devez être inscrit et connecté pour voir ce lien] variant, the -1000, in the middle of this year and has revealed the that stretched aircraft will feature a slightly larger wing than the -800/900 models.

The 369-seat -1000, which has an 11-frame stretch over the -900, is due to enter sarvice at the end of 2015. A separate [Vous devez être inscrit et connecté pour voir ce lien]-1000 design team was set up in 2009, headed by the XWB programme's deputy engineer Alain De-Zotti, which is examining trade-offs for the design, says chief engineer Gordon McConnell. Detailed definition is due to be completed at the end of 2011.

[Vous devez être inscrit et connecté pour voir ce lien]'s operational requirement targets for the -1000 include keeping the approach speed to 150kt (277km/h) at maximum landing weight, compliance with London's QC1 noise requirements for arrival and QC2 for departures, and the capability to reach an initial cruise altitude of 33,000ft (10,000m) in less than 30min.
"With these parameters we were able to do the work to design the wing, and we found that with some changes to the trailing edge we can meet all these requirements," says McConnell.

The wing will feature a trailing-edge extension increasing its area by 4%, which McConnell describes as "quite a big change because it extends the high-lift devices and the ailerons, making the chord bigger by around 400mm. We've been able to optimise the flap lift performance as well as gain more performance in the cruise."

The -1000 design team will work this year to finalise the changes over the -800/900, with some other less significant trade-offs to be completed on the configuration. Windtunnel tests will be run this year based on the enlarged wing, covering both performance and loads. "This will allow us to size the structure properly, which will give us a good idea on the weight delta of the aircraft," says McConnell.

[Vous devez être inscrit et connecté pour voir ce lien]aims to meet the [Vous devez être inscrit et connecté pour voir ce lien]'s mid-2013 service-entry target by compressing the flight-test programme into 12 months, after revealing that it has burnt up some of the development programme's " buffer".

The [Vous devez être inscrit et connecté pour voir ce lien]'s 12-month, 2,600h flight-test programme will begin in mid-2012 with the maiden flight of the first of five development aircraft.

The date for the first flight has slipped by three months because of development delays in the aircraft's structural design, but Airbus is confident it can meet the mid-2013 service entry target for launch customer Qatar
Airways by reducing the original 15-month test programme by three months.

"We've got five aircraft in the flight-test programme - which is more than we usually have," says A350 chief engineer Gordon McConnell.

He says that the original 15-month plan had been generous - some customers had questioned why it would take Airbus so long - and the airframer has been running projects with its flight-test and engineering teams to devise ways of compressing it.

One example is the flight manual process, says McConnell:

"In the past we've done the aerodynamic testing to freeze the configuration, then the performance testing, and then built the flight manual. We've been working to make that a more concurrent effort."

The flight manual will now be built ahead of flight testing and will then be checked during flight-testing, with adjustments being made when necessary.

"We've been able to save quite a lot of time on that critical path," he says.

The first two A350s to fly (MSN001 and 003) will be heavily instrumented. MSN001 will undertake all of the flight-envelope opening at the beginning of programme, to enable the aerodynamic and flight-control configurations to be frozen.

"MSN003 will be more devoted to performance and systems testing, but the two aircraft will be interchangeable because they have the same instrumentation," says McConnell.

The third A350 to fly will be MSN002, which will have a cabin installed. "We'll fly that early in the programme so we can do proper operational testing on the cabin and deliver a mature aircraft to customers," says McConnell.

MSN004 and 005 will undertake operational tests and extended twin-engine operations trials towards the end of the programme, with Airbus planning to have up to four of the first five aircraft airborne before end-2012.

JPRS a écrit:Bonjour

Merci des précisions Sévrien et Jeannot !

Je vois presque avec un certain enthousiasme, l'évolution des programmes A350, tout en positif !
Alors que Boeing, à du sabrer 2 itérations du 787, en 2 Ans, Airbus s'applique à optimiser ses A350 !
Cinq modèles, si j'ai bien compris !
Le A350-8 Old ! pas retiré et on pourrait y revenir un jour, pour une base de MC 5-6000 Nm !

JPRS a écrit:Le A350 - 8 Newlook un peu pluslourd !
Le A350-9 et le 9-LR
Le A350-10

• A350-XWB-800 ;
  
• A350-XWB-900 ;
  
• A350-XWB-1000 ;
  

JPRS a écrit:Salut Sévrien !

Côté A350-8, j'en vois deux et avec 2 moteurs proches, juste du thrust setting !,
Tant que la première version n'aura pas été gommée ! Juste un peu de provoc !
Peut être un futur vers le MC, s'ils baissent encore un peu poids et puissance pour la première version
Ca grattait le Mktg Airbus, il y à 2 ans

Histoire de voire jusqu'ou va l'élasticité du RRXWB ... sous les 70 000 lb peut être

[Vous devez être inscrit et connecté pour voir ce lien]

Qatar Airways backs Airbus rethink on A350-800 design
By Max Kingsley-Jones

A350 XWB launch customer Qatar Airways has declared itself pleased with Airbus's rethink on the -800 variant, which is now based directly on the -900 to offer greater commonality and more range.

"An A350-800 with longer range has more appeal as it differentiates it from the 787-8 and allows operation of long, thin routes," says the airline. It adds that it also likes the fact that it now has "a high degree of commonality with the A350-900".

The rethink was agreed last year in conjunction with the customers, ahead of the second A350 variant reaching its design freeze milestone in December, says the programme's marketing chief Sophie Pendaries. "The planned optimisation of the -800's design - slight changes to the structure and landing gear, tyre and brake changes - was not bringing the expected benefits," she says.

Consequently, Airbus decided to base the shorter model directly on the -900, and trade any penalties against a significant range improvement. The A350-800 now has identical structure and gear to the lead variant, the -900, while the Rolls-Royce Trent XWB engines will be offered at two thrusts - a baseline 79,000lb (352kN) and a 74,000lb derate.

Revised A350-800 specification table

The maximum take-off weight rises by 11t over the previous plan to 259t (with the old variant's 248t still offered as an option). Range (at the higher weight) increases by 460km (250nm) to 15,800km, or payload by 3t. Standard three-class seating remains the same, at 270 passengers.

Désolé je n'arrive pas à copier le schéma sur le site de FG !

C'est ce qui est sorti en Janvier, avec Quatar qui pousse, probablement pour un LA direct ??

JPRS

Sevrien a écrit: Bonsoir / bonjour, chers tous !
Merci, Jeannot ! J'ai dû abandonner mes tentatives de poster l'article et son tableau, en raison d'ennuis techniques passagers !
----------

Pour faire court, .... il n'y pas 2 motoristions différentes pour l'A350-XWB-800.
Il n'y en a qu'une. Ce sont les réglages de poussée qui diffèrent ! Question , pour l'essentiel, de réglage électronique.
---------------
D'ailleurs c'est le même "bill of materials" ('inventaire de pièces'), 'à l'identique' pour les versions des moteurs des A350-XWB-800 & -900.

A l'origine, en stricte conformité avec le cahier des charges, il en était de même ("same bill of materials" ; soit une "commonality- / communauté-moteurs de 100% ) pour les moteurs des 3 versions, A350-XWB-800 / -900 & -1000.

Mais, au moment où Airbus s'approchait de la fin de l'essentiel de la définition finale de la variante -1000, l'avionneur a dû reconnaître un léger surpoids (d'entre 2 & 3 tonnes),
... incompressible à ce stade, et dans la perspective de l'EIS.

Ayant d'abord décidé que RR devait réduire les "thrust settings" / 'réglages de pousée", initialement prévus, ....... Airbus a dû décider de lui demander de les remonter un peu, mais sans atteindre les niveaux de poussée d'origine (plutôt une bonne nouvelle), sauf pour la variante A350-XWB-800, qui remonte à son niveau d'origine, selon le cahier des charges (75,000lbs).

Ensuite, constatation un peu décevante : RR serait obligé d'ajuster le diamètre de la soufflante, en raiosn du surpoids noté sur la variante -1000, pour assurer les performances promises.

Inconvénient, paraît-il :
-- ceci ne permettrait pas une véritable optimisation du moteur, même si ce dernier restait avec le même "bill of materials" ;
-- aussi, les évolutions de la variante du moteur du -1000, imaginables pour une échéance ultérieure, ne seraient pas vraiment optimisables.

RR a dit que, s'il baissait le taux de "commonality"- / 'communauté'-moteurs depuis 100% vers une valeur de 95% environ de "commonality"- / -'communauté', ceci permettrait d'optimiser :
-- les performances de la motorisation de la variante -1000, ....
-- et de ses évolutions ultérieures, .......
-- sans toucher au diamètre de la soufflante, me semble-t-il,......
-- dans des conditions, dont le grand bénéficiaire serait Airbus.

Airbus, sachant que RR n'était pas 'fautif', et voyant bien son intérêt, a fait 'sauter' la contrainte de '100% de commonality' du cahier des charges d'origine !

J'arrête là pour le moment, en espérant que ceci répond à la question.

Je reviendrai, dans un autre post, pour commenter l'article .

Jeannot a écrit:Qatar Airwaus aime bien les nouvelles spécifications du 350 XWB 800.

[Vous devez être inscrit et connecté pour voir ce lien] launch customer [Vous devez être inscrit et connecté pour voir ce lien] has declared itself pleased with [Vous devez être inscrit et connecté pour voir ce lien]'s rethink on the -800 variant, which is now based directly on the -900 to offer greater commonality and more range.
"An [Vous devez être inscrit et connecté pour voir ce lien] with longer range has more appeal as it differentiates it from the 787-8 and allows operation of long, thin routes," says the airline. It adds that it also likes the fact that it now has "a high degree of commonality with the A350-900".

Il parle de l'avion, pas de sa motorisation ! L'enthousiasme du client de lancement est un bon signe !

The rethink was agreed last year in conjunction with the customers, ahead of the second A350 variant reaching its design freeze milestone in December, says the programme's marketing chief Sophie Pendaries. "The planned optimisation of the -800's design - slight changes to the structure and landing gear, tyre and brake changes - was not bringing the expected benefits," she says.
Consequently, Airbus decided to base the shorter model directly on the -900, and trade any penalties against a significant range improvement.

Voilà un point clé ! Contrairement aux dires, parfois quasi hystériques, à l'encontre de cette variante A350-XWB-800 d'une bande de BCL, sous d'autres cieux, qui disait que l'avion serait un "flop", et qu'il n'arriverait jamais à réaliser la distance franchissable promise initialement, soit 15,400 kms. Il est vrai que, par prudence, Airbus avait annoncé une réduction vers les 15,000 kms, quand le surpoids de 2 à 3 tonnes fut observé sur la variante -1000. Aujourd'hui, Airbus a trouvé une excellente solution !

A350-800 now has identical structure and gear to the lead variant, the -900, while the Rolls-Royce Trent XWB engines will be offered at two thrusts - a baseline 79,000lb (352kN) and a 74,000lb derate.

Vraiment astucieux !

[Vous devez être inscrit et connecté pour voir ce lien]

The maximum take-off weight rises by 11t over the previous plan to 259t (with the old variant's 248t still offered as an option). Range (at the higher weight) increases by 460km (250nm) to 15,800km, or payload by 3t.

Très intéresant pour les clients ! Il y en a qui pourront même opter pour un panachage des deux variantes dans la même flotte d'A350-XWB-800, le cas échéant !

Standard three-class seating remains the same, at 270 passengers.

Meilleure capacité que les B787-8 ! Comme nous l'avions dit, cet appareil va pouvoir rivaliser avec le B787-9 ! Qui ne nous avait pas cru? Les BCL !

By not optimising the structure and having higher thrust engines, the reworked -800 has a fuel burn penalty of "a few per cent", although Pendaries claims that its advantage over the rival [Vous devez être inscrit et connecté pour voir ce lien] is unchanged as that programme is not meeting its original performance promises.

Voilà un autre point 'clé' ! Compte tenu du rayon d'action décevant du B787-8 (et du-9, aussi), par rapport aux promesses contractuelles initiales faites par Boeing (Randy BASELER & sa bande........), il y a, maintenant, beaucoup moins de pression sur l'Airbus, en ce qui concerne cette variante ! Au contraire, .... Airbus découvre une nouvelle flexibilité de configuration / exploitation pour cette avion !

Airbus says that the new variant offers up to 1,670km more range than any 787 variant. Compared with the [Vous devez être inscrit et connecté pour voir ce lien], it has a 1,300km advantage and up to 25% lower block fuel per seat.

Oui ! Parce que, les A350-XWB-900 & -1000 offrent déjà "30% lower block fuel per seat", par rapport à leurs rivaux chez Boeing !

The development timetable remains unchanged, with the -800 due to enter service with launch customer Qatar Airways around a year after the -900, in the second half of 2014.
Qatar Airways, which is launch customer for all XWB variants, has told Flight International that it fully supported Airbus in last year's rethink because "an A350-800 with longer range has more appeal as it differentiates it from the 787-8 and allows operation of long, thin routes". It adds that it also likes the fact that it now has "a high degree of commonality with the [Vous devez être inscrit et connecté pour voir ce lien]".

Bien resumé !

Airbus has orders for 182 A350-800s, a further 248 for the -900 and 75 for the -1000 stretch.

Oui ! Réactions ?