Spain's Airbus component manufacturing plant at Illescas has delivered the first lower wing cover for the A350 to the UK wing assembly site at Broughton.
It follows the transport of the upper wing cover, manufactured at the German facility at Stade.
The 32m (105ft) wing cover will be installed on the first flying A350. The aircraft is scheduled to make its maiden test flight by the end of next year.
"This is a major milestone for the A350 programme and for Airbus in Spain," said the head of Airbus's empennage and aft fuselage centre of excellence, Rafael Gonzalez-Ripoll.
Once the main wing structure is complete it will be transferred from Broughton to Bremen for installation of control surfaces, and then moved to the final assembly line in Toulouse.