Boeing and FedEx Express are closely examining developing a new build freighter based on the 767-400ER, offering a production bridge to the recently awarded US Air Force KC-46A refuelling tanker.
Company and industry sources confirm the discussions, which are geared toward providing a replacement to the 72 Boeing MD-10s currently in the logistics company's fleet.
Boeing declined to offer specific confirmation, saying, "We are always in discussions with our customers about their future requirements. We don't share specifics of those discussions publicly."
FedEx also declined to comment, saying "we do not discuss the nature or content of any private discussions we have with vendors or customers."
The size of a potential launch order is not clear, though on a one-to-one basis, the 58 MD-10-10F and 16 MD-10-30F aircraft in the company's fleet would provide fertile ground to launch such a programme.
Additionally, development and production of a 767-400ERF is believed to be intended as a production bridge between the 49 outstanding 767 orders and the start of initial KC-46A tanker production, allowing the existing production system to continue uninterrupted.
Of the 49 outstanding 767 orders, there are 24 767-300ERs and 25 767-300Fs.
Boeing plans the first flight of a KC-46A in 2015, followed by achievement of initial operational capability with the USAF with 18 aircraft by 2017. The KC-X tanker contract, awarded to Boeing last week, is worth as much as $35 billion for replacement of the 179 KC-135 tanker aircraft.
The KC-46A, based on the 767, is equipped with winglets and a 787-derived flight deck will be assembled on the company's newly relocated lean 767 final assembly line inside the rear of its Everett, Washington factory.
Boeing Defense Systems CEO Dennis Muilenburg recently said he expects the KC-X award would spur commercial interest in the 767.
The passenger version of the 767-400ER, introduced in 2000, was a slow seller and was supplanted directly in the company's product line with the launch of the 787-8 and -9.
The airframer delivered 37 aircraft intended for commercial use, including 16 to then-Continental Airlines and 21 to Delta Air Lines from 2000 and 2002, with one additional VIP configured aircraft in January 2009.
The performance of a 767-400ERF is currently unclear, though FedEx was previously working closely with Boeing to develop a freighter conversion programme for low-cycle 777-200 and -200ERs, also for MD-10 replacement.
A launch decision for the 777-200BCF/200ERBCF was expected during the first half of 2011, and a further delay could follow as FedEx evaluates the 767-400ERF.
FedEx announced 1 March that it may eventually order up to 55 new build 777-200LRF aircraft and already has 12 in its fleet.