The ongoing quarrel between Qatar Airways (QR, Doha Hamad International) and Airbus (AIB, Toulouse Blagnac) over fuselage paint defects on some A350s has escalated after the Gulf carrier filed a lawsuit with the London High Court's Technology and Construction division.

"We have sadly failed in all our attempts to reach a constructive solution with Airbus in relation to the accelerated surface degradation condition adversely impacting the A350 aircraft. Qatar Airways has therefore been left with no alternative but to seek a rapid resolution of this dispute via the courts," Qatar Airways said in a statement.

The carrier has stressed that it is primarily seeking to force Airbus to "address [Qatar Airways'] legitimate concerns without further delay". It called for a thorough investigation to establish the root cause of the defects, necessary for any effective remedy.

Airbus said that it had been served with court papers and was analysing their contents. It stressed that it would "vigorously defend" its position.

Qatar Airways was forced to ground twenty-one A350s by the Qatari Civil Aviation Authority over paint degradation. Airbus, backed by the European Union Aviation Safety Agency (EASA), claims the defects are not structural and have no impact on safety. Other carriers have also reported similar defects on their A350s, albeit to a lesser degree. No other airline or regulator has, however, grounded the type.

Qatar Airways operates thirty-four A350-900s (including sixteen grounded units) and nineteen A350-1000s (five grounded), the ch-aviation fleets module shows. The airline has a further twenty-three A350-1000s on firm order but paused all future deliveries pending the resolution of the current dispute.

Airbus recently said it would seek independent legal advice regarding what it dubbed "misrepresentation" of the issue by Qatar Airways.