A tier-one supplier to Airbus believes that the wrong type of resin material has been chosen for the A350's wing spars and is urging the airframer to rethink the selection.

GKN, which manufactures composite wing spars for the A400M and A350 at its Isle of Wight facility, considers Cytec's 977-2 resin material to be "technically superior" and "easier to process" than Hexcel's M21E, which was selected on the A350.

Chief technologist and senior technical director Phil Grainger says that M21E is "unformable" due to its thermoplastic content and its relative lack of fluidity. Its selection on the A350 requires GKN to deploy automated fibre placement rather than the double diaphragm forming it deploys in manufacturing the A400M wing spars, for which 977-2 is the selected resin material.

According to Grainger, GKN has "proposed a return to 977-2" on the A350, following the difficulties it experienced in processing M21E. To support its proposal, it "undertook and successfully formed representative spars" using the European Union-funded Advanced Low Cost Aircraft Structures (ALCAS) forming tool, "which has very similar to A350 geometry". The forming tool in question was developed within the EU-funded Advanced Low Cost Aircraft Structures (ALCAS) programme.

Grainger is confident that the 977-2 will ultimately be selected on the A350. He believes Airbus may already have reversed its decision to select M21E over the Cytec product. "Expect a change," he says.

However, Airbus says the selection of the Hexcel resin is "a confirmed decision". It adds that the decision was based on M21E's commercial and technical performance, and denies that 977-2 was even considered for the A350 application.

An A350 spar trial is scheduled for January, the same month in which GKN is expected to formally take ownership of Airbus's Filton wing factory.

Source: Flight International