Airbus, famille A320, avec "winglets"

Airbus has concluded testing of A320 Blended Winglets developed by Aviation Partners that it launched in December and is "4-6 weeks" from making a decision on whether to proceed with the program, Airbus Executive VP-Programs Tom Williams told media in Hamburg this week (ATWOnline, Dec. 18, 2008). Director Product Marketing-A320 Family Stuart Mann said the manufacturer is "taking time to evaluate what we've learned" and that a conclusion will be reached "in a few weeks time, hopefully. . .the result [of the testing] doesn't exist yet."

In a statement, he added that winglets are "one of the elements that we are looking at for the future to ensure the A320 family stays competitive."

Later, Mann said the €100 million ($136.1 million) spent on research and development each year will keep Airbus's single-aisle aircraft family relevant for at least the next 10 years and that a next-generation replacement will require "game-changing" technology--meaning a 20% efficiency improvement--to "justify changeover costs" for airlines.

"The technology isn't available today. We're looking toward the end of the next decade for something like that," he said.

Elaborating yesterday, Head of Market and Product Strategy Laurent Rouaud said that "anything less than a game-changer would be almost irresponsible" and that a 40% improvement in fuel burn and a double-digit improvement in operating economics are the targets for the "end of the next decade."

Dubai 09: Boeing's Tinseth welcomes Airbus to winget club
By Jon Ostrower

Boeing's vice-president of marketing Randy Tinseth has welcomed Airbus to the winglets club with a question. "Why has it taken so long?" he asks.

Airbus announced on Sunday at the show that it would offer winglets for its A320 family aircraft starting with an order from Air New Zealand in 2012 that would improve fuel burn by 3.5%.

Tinseth claimed that depending on the model, the 737 Next Generation aircraft has a 3-7% per seat fuel burn advantage over the A320 family aircraft and adds that Airbus is "trying to claw a little bit back with their new winglets".

Boeing first introduced winglets on its Boeing Business Jet in 1998 and commercially in 2001.

Airbus claims that its new "sharklet" A320 winglets will best Boeing's 737-800 in relative fuel burn by about 9%.

Airbus’ ongoing trade studies on the winglet or “sharklet” designed for the A319, A320 and A321 have all but concluded that retrofitting the device may not be feasible or cost effective given that the raft of changes needed to the centre wingbox modifications, front wing spar and pylons. The level of design changes required negate the fuel burn savings identified versus those of new build airplanes that have the strengthened components built-in from the outset during assembly.

On the A319 specifically, retrofitting the winglets/sharklet was described by an one engineer as a “non-starter” given that the outboard wing bending relief required much greater stiffening than first thought to counter the moment arm of the shorter airplane. The jet maker has no plans to incorporate winglets to the A318, either on existing or new build airframes. Airbus had encountered similar issues when trialling previous winglet designs, electing to drop those proposals as weight and stiffening requirements adversely affected the front and rear spars of the A320 wing, including greater torsional forces and stresses on the unstrengthened centre wing box.





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Airbus had noted at the Dubai Air Show last fall that additional wingbox strengthening would involve another “200kg” weight, however, the reinforcements could be as much as 350kg. Offsetting some of this weight would emerge through ongoing program weight saving, although it is not clear whether the efforts would be enough to maintain the 3.5% fuel burn reduction and still deliver the boost in range.

Airbus states that there would be a range increase of up to 150nm or a corresponding payload increase of half a ton, depending on configurations of each model. On a comparative basis:

• The 737-700 would still have a 7% range advantage (3440nm) over the A319WE (Winglet Equipped)
  
  
• The 737-800 would still have a 5% range advantage (3115nm) over the A320WE (Winglet Equipped)
  
  
• The 737-900ER* would still have a 15% range advantage (3115nm) over the A321WE (Winglet Equipped)
  

Winglet equipped A320’s would also incur additional weight penalties for the planned re-engine strategy which Airbus hopes to finalise this year. Qatar Airways had been seen as a prime candidate as launch customer for the A320 re-engine model, however the airline is poised to announce an order for the lacklustre CSeries at the Farnborough Air Show in two weeks time.

One major US-based A320 operator has baulked at Airbus’ plans for both the winglet and re-engine moves claiming that the weights being advertised are so heavy, that the dual-wheel landing gear legs need to be substituted for a four wheel bogey to compensate for the increase in weight as a result of the major wingbox and wing changes needed to fit the Pratt & Whitney PurePower GTF engine.

Despite being lighter, the CFM International LEAP-X engine option would still require significant beefing up of the wingbox, pylon, wing spars to accommodate the engine.

The gap between the fuel burn dynamics on the A320 and 737 families widens next year with the introduction of the CFM56-7BE engine (formally known as the Evolution) which aims to deliver a further 2% fuel consumption improvement (with aerodynamic changes). CFM is also using the CFM56-7BE platform to target further efficiencies with PIP upgrades with a view to attaining another 2% or more cut in fuel burn from the engine alone, however it has no plans to offer the same on the A320 engines as of yet.

While Airbus has opted to concentrate its near-term efforts on integrating the wing tip device for its new build jets, it is “continually looking at ways” to reduce the weights involved in the strengthening of the wingbox and surrounding structures to eke out more aerodynamic efficiencies.

Airbus is finally granting JetBlue's wishes for a winglet retrofit programme, and is working with the airline to become a launch customer to retrofit its existing A320 fleet. JetBlue's A320 deliveries from 2013 will feature sharklets first unveiled by Airbus in 2008.
JetBlue has not yet selected an engine for its A320neo aircraft, but all its existing narrowbodies are powered by the V2500. Deliveries of the A320neo are scheduled to begin once the carrier accepts delivery of all 52 A320 family aircraft from its existing orderbook.

Astuteman :
As an aside, I think we're going to find that the newer wing with the winglets also adds some 2t to the fuel capacity - an area where the A320 has been seriously disadvantaged up to now, and one which causes the sometime transcon difficulties. The wingletted A320 classic will be a substantially different beast to the current plane, even without the re-engine

The wing modifications will also result in the A320 having an increased fuel capacity, that is now one of the reasons the B738-NG flies further then the A320. So that advantage will be "returned" to the A320 with shark-lets (OEO and NEO will receive this performance-upgrade).

Airbus has already started to produce the first elements of the “sharklet” wingtips for incorporation on wings for standard A320 aircraft that are expected to enter service in about 18 months’ time, during the fourth quarter of 2012. It also has begun to convert the original A320 (MSN 0001), including installation of flight-test instruments, to act as a test bed. Sharklets will then be introduced progressively during 2013 on other members of the single-aisle family in the following order: A319, A321, A318.
Introduction of sharklets will improve A320 takeoff performance in terms of payload by approximately 6,600 pounds, according to Airbus customer chief operating officer John Leahy. This enhancement is seen as especially valuable when operating from runways with obstacle-clearance and secondary-segment climb limitations. Leahy cited airports such as Canberra, Chicago (Midway), Kathmandu and Quito as having such considerations for A320 operators.
Alternatively, carriers might wish to use the new aerodynamic equipment to increase their range of operations through the sharklets’ claimed higher fuel efficiency. Leahy said block fuel usage could improve by more than 3.5 percent when compared with a current A320 fitted with standard wingtip fences. By April this year, Airbus had announced eight sharklet customers: Air Arabia, Air New Zealand, lessors Air Lease and Avalon, Finnair, LanChile, Thomas Cook and Virgin America.
The new wingtips are said to provide lower fuel burn and emissions; improved payload/range capability, takeoff, climb and cruise performance; and enhanced aircraft value. Flight testing of the units on A320 MSN001 are scheduled to begin in late 2011 followed in the first quarter of next year by delivery of the first new wing for final assembly on the production line. Airbus programs executive vice president Tom Williams said 2012 will see production of a significant number of sharklet-ready A320 wings. “It will be a very quick ramp-up,” he said.
A320 wing changes to accommodate sharklets include a rebuilding of Rib 27, a move Williams characterized as a “very neat solution” that will allow the new tip to be plugged into the end of the wing. Sharklets can be fitted in a one-day shop visit and will be removable.
Williams also said there is no requirement for fundamental redesign of the structure or the low-speed flight controls. There will be no change to materials and the wing spars will “look very much like they do now.” Because sharkletted A320s will operate at increased maximum takeoff weights, skin panels will be re-gauged over the entire wing span for a 1.3-percent higher static load. The panel gauge also will be changed to accommodate a 3-percent higher fatigue load over most of the wing outboard of the engine.
Higher maximum takeoff and landing weights will require local gear-rib and spar reinforcement, alongside local reinforcement of engine-pylon attachments with adapted pylon-system interfaces. The outer wing will be reinforced to take onto account higher bending yaw and torque forces; the center wingbox also will be reinforced. A weight-reduction program is being conducted in an effort to ensure that it will not be possible to differentiate between a 2010 A320 and a 2012 example with the modified wing

Meanwhile, Williams also promises the first flight of the A320 MSN1 with winglets still this year. The first flight has been delayed, slightly, as it is taking Airbus longer to install the devices it calls "Sharklets." But flight testing has been adjusted to assure the certification and first flight schedule will hold, Williams in

Airbus has rolled out its A320 test aircraft following the fitting of 'sharklet' wing-tips, which will be an option on new-build aircraft and standard on the re-engined A320neo.

The test aircraft, MSN1, will undergo flight-testing "in the coming weeks", said the airframer.

Sharklets, which replace the A320's wing fences, will reduce fuel-burn on the type by up to 3.5% on longer sectors of around 3,000nm (5,560km), Airbus claims.

The airframer also expects the sharklets - each of which is 2.5m (8.2ft) tall - to improve take-off performance by up to 3t.

This would provide the A320 with a higher available take-off weight from runways subject to obstacle limitations.


© Airbus

MSN1 will be used to assess the performance of the modification, while Airbus will begin building wings next year which are capable of supporting the new tip.

Installation of the sharklet requires inboard and outboard reinforcement to handle different loading, as well as changes to outer wing ribs to accommodate the structure.

Several carriers have already signed to take the sharklets, including Air New Zealand, Air Arabia, Finnair and LAN.