A Tier One UK aerospace supplier has been awarded the contract to produce the pylon box assembly that attaches the engine to each wing of an Airbus A319, A320 and A321 neo (new engine option) single-aisle jetliner.
After extensively researching the market, the sub-contractor installed a new dedicated machining and assembly cell at one of its production facilities.
The process is now fully developed for manufacturing the left- and right-hand pylons at a rate destined to rise to 50 pairs per month by 2019.
The cell includes a German-built Hermle C 42 UP twin-pallet vertical-spindle five-axis machining centre for finish-milling a titanium rib.
Two three-axis vertical machining centres for initially roughing material from titanium billets and a large pylon assembly area complete the equipment devoted to this project.
The sub-contractor develops close long-term business relationships with its customers and is often involved in life-of-programme agreements.
It therefore needed a manufacturing solution for the Airbus pylon that would support the speed and reliability of production that the customer expects, while at the same time keeping an eye on costs so that a competitive tender could be offered.
The five-axis machining centre was a key part of this project; it also represented a significant tranche of the investment.
The Hermle option was selected based on suitability for purpose, value for money and an established association with the UK sales and service agent — Gosport-based Geo Kingsbury (
www.geokingsbury.com).
Other factors in favour of the Hermle C 42 UP were the Heidenhain control, the high-torque spindle (necessary for machining titanium 24/7) and Hermle’s extensive database of machining knowledge at its production plant in Gosheim, which included information directly relevant to the pylon application.
While all other ribs in an Airbus neo jetliner are made from aluminium, the pylon rib must be machined from titanium, so as to withstand the higher temperatures generated by the new engine — either Pratt & Whitney’s PW1000G
or CFM International’s LEAP-1A.
The production route starts with a titanium billet, which is rough machined on one of the two three-axis VMCs. It is then finish-milled on the Hermle to tolerances down to ±0.1mm in a five-axis cycle that uses the machine’s rotary table/swivelling trunnion.
Op 1 is completed on the first pallet and Op 2 on the second, with the assistance of special fixtures made in-house. Overall, around 90% of the billet is removed.
The ribs are assembled with mainly aluminium parts and fabricated titanium components on modular benches alongside the machining centres. When complete, they are delivered to the Airbus plant in Broughton, where the wings for all the company’s civil aircraft are assembled.
Richard Kingsbury, managing director of Geo Kingsbury, said: “The aerospace industry has seen enormous changes over the last 10 years, with many new product introductions and frequent design changes.
"Sub-contractors in the supply chain have to be ‘nimble’ to cope with this challenging global business environment and compete effectively.
"There is a pressing need to put in place efficient production methods based on lean-manufacturing principles, and this installation is a prime example.”