Airbus sales chief John Leahy said on Tuesday he was not worried about Boeing adopting a larger engine for its 737 MAX 9 jet, dubbing it "Mad MAX" because of the technical challenges it would face.
Reuters reported on Sunday that Boeing was looking at modifying a larger 'LEAP' engine used on Airbus' hot-selling A321neo to make a 737 with more capacity and range.
Boeing would probably go ahead with the upgrade rather than build a widely touted and costlier jet in the 'middle of the market,' where Boeing is studying a gap between short-haul and big wide-body jets, Leahy told journalists.
Boeing said it was in continuous dialogue with customers.
Industry sources have drawn a distinction between Boeing's tactical defence of the 737 and longer-term discussions about a larger mid-market jet with about 220-260 seats, which could in turn prepare the ground for a full 737 replacement after 2030. While dismissing Boeing's plans to upgrade the 737 to compete with a larger Airbus model, Airbus said it remained in talks with airlines about adding to its own A350 family with a bigger version, sharpening competition at the top of the market.
But conscious of the threat of drawing demand away from its existing A350 line-up, it said it did not expect the bulk of the airline business to be attracted to a 400-seat twinjet.
It also dropped into its annual media briefings a new working name for the possible jet, the A350-2000. Reuters reported in March that Airbus was informally marketing a 400-seat jet, known internally at that stage as the A350-8000, to better compete with the 406-seat Boeing 777-9.
The project is the latest move in a game of leapfrog played by Airbus and Boeing in the market for big twinjets, valued at $1.9 trillion over 20 years.
Fabrice Bregier, president and CEO of the Airbus Group plane making unit, said he was not yet convinced about the idea, because Airbus needed to ensure that it did not merely transfer orders from the 366-seat A350-1000.
Two airlines whose stance is seen as decisive in whether Airbus launches the new jet are Singapore Airlines (SIAL.SI) and British Airways (ICAG.L).
"If they buy it, Airbus will build it," a senior industry source said.
Bregier also issued a new warning to cabin suppliers over delays and manufacturing faults that have disrupted deliveries of A350 jets. One problem has been that some of the lavatory doors do not close properly, he said.
Airbus said the sole supplier of lavatories for the A350 is Zodiac Aerospace, which was not immediately available to comment.
Bregier said, without naming companies, that Airbus would over time remove cabin equipment suppliers that failed to perform.