British Airways is trying to nudge Boeing and Rolls-Royce to provide a winglet modification for the flag-carrier's Boeing 767-300ER fleet, although the relatively small size of its fleet could prove an obstacle.
The airline's fleet of 21 aircraft - of which 13 are in long-haul configuration - are fitted with Rolls-Royce RB211 engines, in contrast to the Pratt & Whitney and General Electric powerplants fitted to almost all other 767s.
BA chief executive Willie Walsh, speaking to ATI at an event in London, said that the airline was "gently pushing" both the airframer and the engine manufacturer for the upgrade.
While there is a supplemental type certificate for winglets on the P&W- and GE-powered 767, the RB211 engines generate a different wing loading, says Walsh.
He wants Boeing to pay for the development, although he says he "understands" that the manufacturer could be reluctant to fund a programme for a limited number of aircraft.
He says that BA's fleet is relatively young, at about 13-14 years, and the 767s could provide at least another six years' service to the carrier.
Winglets would provide a substantial fuel saving, he says, and create a case for retaining the aircraft in the fleet to give BA additional flexibility even as it introduces its intended 767 replacement, the 787.
"Clearly the sooner it's done, the better," he says. "If this [modification] had been available two years ago, we would have done it then."
Qantas operates seven RB211-powered 767s, but the carrier took the twin-jets from the BA fleet. China Eastern Airlines also has a handful of 767s with Rolls-Royce engines.