Emirates and Qatar Airways each appear prepared to spring a surprise during the show and are likely to express initial reactions to Airbus's newly-disclosed delay of the A350.
Qatar Airways, the launch customer for all three A350 variants, had already seen service entry for two of them - the A350-800 and A350-1000 - pushed back as Airbus focused resources on the A350-900 and revised the specification of the A350-1000.
While Qatar has stayed silent on the A350-900, whose delivery has slipped by up to six months, pushing it far into 2014, the delay will put Airbus under further pressure from both Gulf carriers, just a few months after they each criticised the redesigned A350-1000.
A350 programme chief Didier Evrard said the delay was aimed at ensuring the final assembly line contained only a "manageable amount" of outstanding work, to avoid a logjam.
Qatar Airways' outspoken chief, Akbar al-Baker, is hardly likely to contain his opinions. Qatar is in line for possible A380, A320neo and Bombardier CSeries orders, all of which had been expected at the Paris air show.
Emirates has long praised the Boeing 777, and is particularly keen to study prospects for a successor. It had seen the A350-1000, for which it has 20 orders, as a potential replacement for 777-300s but the redesign has cooled Emirates' enthusiasm.
Kuwaiti lessor ALAFCO, also an A350-900 customer, still has an outstanding deal for A320neos which is yet to be firmed, while Oman Air has been considering a firming of Boeing 787 options. Five Middle Eastern operators hold orders for 131 Boeing 787s.
Gulf Air has kept its fleet plans discreet, partly because of unrest in Bahrain, but a government statement earlier this year confirmed a deal for Bombardier regional jets - which would probably be CSeries - and Gulf Air could formally declare its hand at the show, as well as its restructured fleet plans.
Source: Flight Daily News