Airbus is yet to disclose full technical details of a plan to offer large winglet retrofit on its A320-family aircraft as it prepares to start producing new-build aircraft with a "sharklet" wingtip modification.
US carrier JetBlue Airways, which has pressed for a retrofit option, is to be a launch customer for the retrofit programme. It is already intending to take sharklet-equipped A320s from 2013.
The airframer is to start producing sharklet-equipped aircraft next year, after Air New Zealand launched the programme in 2009, and the modification will form part of the standard-build wing for the A320neo.
But Airbus said it had been "encouraged" by the sharklet scheme and has "decided to pursue" a retrofit for in-service A320s - although it has yet to decide whether to develop the winglets in-house or externally. "We are evaluating the technical, operational and business aspects," it said.
US Airways flight training managing director Bob Skinner described winglet retrofit requirements for the A320 as "extensive" earlier this year.
JetBlue said it is still waiting for "slightly more information" from Airbus regarding "exactly what the final solution is, and what the availability of the kits will be".
Although the carrier, which undertook A320 winglet trials with Aviation Partners, said it did not have "final numbers" for the improvement in fuel burn, it expected a "fairly short" payback interval.
Sharklets are intended to provide an improvement of about 1% in fuel burn on 500nm (925km) sectors and up to 3.5% on flights of 3,000nm.
Airbus executive vice-president of programmes Tom Williams added that the winglet retrofit would "enhance" residual value on baseline A320s.