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Juergen Lehle
BAe 146 Regional Airliner
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3T RPD
The breather pipe in CAD.
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3T RPD
A breather pipe prototype made using additive manufacturing.
When it comes to working for a big client, it is hard to find bigger than BAE Systems and 3D printing expert 3T RPD rises to the occasion when faced with this kind of high-importance precision project from an international aerospace giant.
BAE Systems approached 3T for additive manufacturing solutions in order to rapid manufacture crucial parts that would keep working planes on the ground without it.
The company’s Regional Aircraft arm provides support and engineering services for its in-service fleet of more than 500 commercial aircraft all over the world. As part of its ongoing spares support for the BAe 146 regional airliner, the global aerospace giant was required to replace a small pipe that forms part of the cabin windows in order to stop condensation forming.
This small but important component is called a breather pipe and has been produced in the past using traditional injection moulding techniques, but the tooling for this part had become damaged and replacement tooling would have taken months to produce, costing in the region of £14,000.
It was, therefore, vital the component could be reproduced quickly to prevent dozens of planes from being grounded. The Regional Aircraft team at Prestwick realised that additive manufacturing could provide a solution to the problem. The team designed the replacement breather pipes and BAE Systems' Military Air & Information department rapid prototyped the first designs.
This is when 3T received the call to develop the product for batch manufacture. 3T utilised CAD files from BAE and produced numerous example parts. Quality Assurance inspections highlighted potential for improvement prior to going into production. For example, the original pipe had a very small diameter with a sharp bend and both these features caused difficulties as they made the removal of loose powder tricky, with residual powder restricting air flow and subsequently making the part unreliable.
3T's Quality Assurance, CAD and customer service teams worked alongside the professionals at Regional Aircraft to understand the part's critical features and then worked on the design changes necessary to facilitate the successful 3D printing of the component.
The CAD was modified to widen the pipe diameter (without changing the external dimension) and smoothed the line of the pipe so that the radius of the bend was less acute and more rounded.
Moreover, test builds completed at 3T led the Quality Assurance team to identify that placing the part in a specific build orientation resulted in more consistent production.
Thanks to this collaborative effort, the breather pipe is now in stock at BAE Systems Regional Aircraft's spares warehouse and these components are being used by BAE's customers on in-service aircraft. The projected timeframe for manufacturing the pipe using injection moulding was six months, while using 3D printing reduced this lead down to just four weeks.
Structures Support Manager for In-Service Aircraft at BAE Systems Regional Aircraft Philip Beard commented: "Not only was there significant time saving and the avoidance of the tooling cost, but the actual parts cost 60 per cent less than when manufactured using the traditional method.
"Having achieved this first breakthrough on the BAe 146 window breather pipe, we are now looking at a range of other 3D printing opportunities to provide replacement parts across several different commercial aircraft types. This technology offers a potential solution for aircraft parts which are prone to obsolescence, where tooling is unavailable, for quick turn rounds and also for small batch production."
The part produced using 3D printing has already been fitted on flying planes under EASA (European Aviation Safety Agency) Form 1 certification. BAE Regional Aircraft makes and supplies parts through its EASE 21J and 21G approvals. 3T RPD holds AS9100 (the aerospace certification scheme) for the production of metal parts using additive manufacturing, alongside ISO9001 and ISO 13485 (the medical devices standard) and this ensures that 3T has the necessary systems in place to provide quality parts to customers for use in the most critical environments.
