A logo of Airbus is seen at the entrance of the Jean-Luc Lagardere A380 production plant at Airbus headquarters in Blagnac, near Toulouse, France June 18, 2020.
A logo of Airbus is seen at the entrance of the Jean-Luc Lagardere A380 production plant at Airbus headquarters in Blagnac, near Toulouse, France June 18, 2020. Reuters / Stephane Mahe

Airbus faces a delay of several months in the introduction of its A321XLR jetliner, pushing its start date out to 2024, as European regulators consider imposing changes to a lower-fuselage design to contain potential fire risks, industry sources said on Wednesday.

The latest upgrade to the planemaker's best-selling A321 single-aisle jet had been due to enter service in late 2023, but that timetable has been delayed by discussions with regulators about certification of a new rear-central fuel tank.

The European Union Aviation Safety Agency (EASA) is looking at imposing significant changes to the design of the "underbelly fairings," part of the plane's lower structure, a senior industry source said.

Such work could add 6-9 months of extra work depending on the scope of the final certification rule, the source added. A second source said this and other work could add as much as a year onto its production.

Airbus and EASA confirmed they were in talks on how to certify the new long-range narrowbody model, but declined to provide details.

"The certification of the A321XLR is an ongoing project," an EASA spokesperson said.

"The complete set of conditions in relation (to) the installation of the rear-centre tanks is still under definition, and, when ready, will be published for comments."

An Airbus spokesperson said, "As the discussions with the airworthiness authorities are still ongoing, we are not in a position to comment".

Rival Boeing has expressed concerns about fire risks from the new A321XLR design. The certification talks surround the question of whether extra protections to the plane's underbelly are needed in the event of a crash.

Bloomberg News reported earlier that any design changes could also shorten the Airbus plane's range, a key battleground in its battle with Boeing in the busiest part of the market.

Airbus is due to publish quarterly results on Wednesday evening when it routinely updates investors on development plans as well as progress towards proposals to raise jet production.