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.