The ad, which appears this week in trade publications including Aviation Week and Flight, asserts that Boeing is "stretching the truth" in its own campaign to promote the aircraft. Boeing said it stands by its performance claims.
"They crossed a line when they started running specific numbers," Airbus's sales chief, John Leahy, said yesterday in an interview. "They've blatantly misrepresented the facts."
The bickering highlights the stakes in the $70 billion global civil aviation industry as the companies fight to trump each other in orders. Airbus is set to lose its delivery lead this year for the first time in almost a decade, after Boeing overcame production delays and began shipping its new 787 Dreamliner to customers.
Airbus and Boeing are both drawing comparisons with each other's narrowbody aircraft, the industry's workhorses, and their four-engine A380 and 747-8 jumbo jets. Leahy said Airbus was driven to act only after Chicago-based Boeing ran ads with specific claims about the alleged superiority of its 737 Max over the A320Neo and the 747-8 over Airbus's A380.
The 737 Max ad claims the plane's costs on a per-seat basis are 8 percent less than an A320neo's. Toulouse, France-based Airbus wrote to Boeing's general counsel complaining the numbers are "wildly out of line" and placed ads targeting airlines only after the U.S. company failed to respond, Leahy said.
"We received the letter and responded weeks ago that we are fully confident in the accuracy of the statements made in our advertisements," Marc Birtel, a spokesman at Boeing's commercial headquarters in Seattle, said in an email.
The two planemakers combined have delivered more than 12,000 narrowbody planes since Boeing 737s reached their first customers in 1967. In its ad, Airbus said it is now dominant in the market for very large aircraft with the double-decker A380, a niche where Boeing has struggled to match the popularity of previous iterations of the iconic 747 jumbo.
Airbus and Boeing have sparred in public before. Some 15 years ago, Airbus took out ads touting the four-engine A340 as safer than a twin-engine Boeing model. Boeing took umbrage that its rival had breached an unwritten understanding not to use safety issues to market planes.
The manufacturers have promoted competing planes with different sets of numbers for decades, each choosing parameters that would give its own model an edge with buyers. Both the upgraded 737 and the A320 will boast new engines, the main factor contributing to improved efficiency.
"The truth about these claims is that neither side knows," said Richard Aboulafia, vice president of consultant Teal Group in Fairfax, Va. "These are engine-driven aircraft," and until they have been fully developed and start tests, it's impossible to know what they can offer, he said.
Airbus's A320neo is scheduled to make a commercial debut in late 2015, while the Max is due to enter service in 2017, according to timetables outlined by the planemakers.
Boeing said Nov. 15 that the 737 Max has reached "firm concept" in the development process, with larger engines, a redesigned tail cone and winglets. The company also announced some systems changes, including the addition of large cockpit displays, similar to those for the Dreamliner.
Boeing doesn't expect to reach the "firm configuration" milestone for the Max until next year and won't begin building the first test plane until 2015.
"We're confident in our performance claims based on our historical and projected performance for the airplane," Boeing's Birtel said.
Airbus has won 1,515 orders for the A320neo, the fastest-selling model in civil aviation history, after a head start of about six months over the Max, which has 969 orders. Boeing has delivered about 7,400 737s since 1967, making the jet the world's most widely flown airliner.
Airbus was concerned that some "less sophisticated airlines" might be swayed by Boeing's claims and be less inclined to talk to Airbus, Leahy said. The sales chief said he didn't know what Airbus will do if Boeing ignores its ads.
"We'll take one step at a time," he said.
Andrea Rothman: firstname.lastname@example.org