British Prime Minister David Cameron will attend the opening day, where he is expected to finalise multi-billion dollar deals with Boeing to buy nine P-8A Poseidon maritime patrol planes and to upgrade 50 Apache helicopters.
Industry sources said Airbus's A350-1000 deal with Virgin Atlantic provided a shot in the arm to a 366-seat model promising greater efficiency but whose sales have slowed as Boeing develops a larger version of its 777, prompting a game of leapfrog between the only two makers of long-haul jets.
Airbus declined to comment and Virgin Atlantic was not available to comment.
Airbus and Boeing have enjoyed years of strong demand, helped by rising airline travel particularly in Asia and the Middle East and new, more fuel-efficient planes.
But with the industry's order backlog standing at a record 13,500 planes at the end of 2015, or 9.6 years of production at current rates, analysts are worried that economic risks - from slowing growth in China to Britain's move to leave the EU - could see orders dry up and some even cancelled.