Following delivery last week of the first 787-9 rudder built in China by Chengdu Civil Aviation (CCAC), Boeing extended its supply chain further for yet another airfoil subassembly, choosing the UK’s GKN Aerospace to build the winglet for the 737 Max. GKN joins Korean Air Aerospace Division (KAL-ASD) in South Korea as co-supplier of the raked, dual-feather-design winglet.

The dual-feather winglets, which feature upward- and downward-directed composite airfoils joined with a metallic center piece, would contribute at least 1.5 percent of the 8 percent operating-cost advantage Boeing claims the 737 Max 8 will hold over the Airbus A320neo.

“We announced our first winglet contracts for Boeing aircraft in 2007 and this award reflects the ongoing success of our growing relationship,” said GKN Aerospace and Land Systems CEO Marcus Bryson. “It also draws on our expertise in the efficient manufacture of complex composite and metallic wing structures and makes full use of our ability to assemble this advanced structure.”

GKN has promised to deliver the first developmental winglet ship sets to Boeing in 2015, ahead of first flight in the second half of 2016 and first delivery in the third quarter of 2017.

Separately, CCAC’s delivery on December 2 of the first Chinese-built 787-9 rudder to Boeing marked the fulfillment of contract terms set in 2012. Since then, Boeing’s composite manufacturing center in Fredrickson, Wash., built the program’s first five rudders to ensure a smooth transition of sole-source production to CCAC. Also the rudder supplier for the 787-8, CCAC now makes 10 Dreamliner rudders per month to match Boeing’s production requirements.

Other Chinese suppliers that provide major structure assemblies to Boeing include Shanghai Aircraft Manufacturing (737 horizontal stabilizer) and Xian Aircraft International (737 vertical fin).