Airbus’s mid-life update for the A320 family has hit trouble with the revelation that it is unlikely to adopt new large winglets that were central to expected fuel burn improvements.

The manufacturer has been undertaking back-to-back tests of two winglet designs since April – one designed in-house and the other by US company Winglet Technology. Evaluations have been carried out on the prototype A320 as well as a production aircraft built for JetBlue, with a view to developing a retrofit programme, as well as for possible inclusion in the package of upgrades that Airbus is planning for the so-called “A320 Enhanced”. Other Enhanced improvements include an aerodynamic tidy-up (to the engine pylons, surge tank ducts and upper belly fairing), engine improvements, weight savings and a new cabin.

Airbus chief operating officer customers John Leahy said earlier this year that the aim of all the improvements was to reduce fuel burn by 4-5%, with the winglets alone expected to “get a couple of per cent” of this.

However, Airbus says that the “latest information on the A320 winglet testing is that the results indicate that although improvements were found in terms of cruise drag, the increase in structural weight that would be necessary to support the winglets largely offsets the gain”. However, it adds that “at this stage, it is too early to say that the winglet programme is over completely”.

Airbus says the other improvements announced for the A320 Enhanced, including the aerodynamic and engine improvements, continue to be worked on. The new cabin, which will offer a 50kg (110lb) weight saving, will enter service in mid-2007. Airbus had said earlier this year that it was aiming for a design freeze on the Enhanced before the end of 2006, with the aim “to provide most, if not all, of the improvements by 2008”.

Source: Flight International