Qatar Airways has grounded 13 Airbus A350s over what it described as fuselages "degrading at an accelerated rate" in the long-range aircraft.
The dispute between the Middle Eastern Airline and the European airplane maker has increased due to the alleged issue.
While Airbus declined to specifically discuss the announcement, Qatar Airways' announcement to journalists raised questions about the A350s' carbon composite fuselage, designed to make the twin-aisle aircraft lighter and cheaper to operate by burning less jet fuel. The wings for the A350s are made at Airbus' manufacturing plant in Brought, north Wales.
Qatar Airways also is one of the world's top operators of the aircraft. In its statement, the airline said it had been monitoring the degradation beneath the paint on the fuselage of the aircraft for some time.
It described the issue as a "significant condition," without elaborating.
"Following the explicit written instruction of its regulator, 13 aircraft have now been grounded, effectively removing them from service until such time as the root cause can be established and a satisfactory solution made available to permanently correct the underlying condition," the airline said in its statement.
Qatar Airways has a fleet of 53 Airbus A350s in both its 1000 and 900 series. The airline has another on order with the France-based airplane manufacturer, making its total order of 76 aircraft - the most of any airline worldwide.
Airbus declined to specifically discuss Qatar Airways' grounding.
"As a leading aircraft manufacturer we are always in talks / working with our customers," a statement said. "Those talks we keep confidential. We have no further comment on our customer's operations."
Currently, Singapore Airlines is the world's top operator of the A350, with 56 now in its fleet. The airline did not respond to a request for comment.
