Additive Manufacturing takes flight

26 February, 2025

In aerospace, critical components must meet exceptional standards of precision, strength, and reliability - characteristics that are equally vital in hydraulic and pneumatic systems. Advanced manufacturing techniques, such as additive manufacturing (AM), are revolutionising precision component production across industries. This case study highlights how Tronosjet Manufacturing achieved FAA certification for a vital aerospace part using AM techniques. While the focus is on an aerospace application, the engineering principles and regulatory challenges described here resonate with the demands faced by fluid power systems in highstakes environments like aviation.

Founded in 2001, Tronosjet Manufacturing is a Canadian company specialising in aircraft leasing, major modifications, and maintenance. Historically, the company has managed a fleet of over 60 BAe 146/Avro RJ aircraft, including engines and spare parts. In 2016, Tronosjet expanded its operations by establishing an advanced manufacturing division to produce aerospace components using additive manufacturing.

The division offers a complete AM service, including design, printing, heat treatment, post-processing, and metallurgical testing. Its facility is certified as an Aerospace Manufacturing Organisation under Transport Canada 561 and holds AS9100 approval for design and development. Despite AM’s growing adoption, very few components have received FAA approval, which prevents many customers from flying them. To showcase AM’s potential, Tronosjet selected a BAe 146 part for production: a cast magnesium engine thrust control pulley bracket, which suffers from corrosion issues. The bracket is a critical component that redirects engine cables travelling from the cockpit to the pylon connecting the engine to the airframe.

“The thrust control pulley bracket was determined by the FAA to be a Class 1 (critical) part, essential for the safety of the aircraft,” explained Jeff Campbell, Director of Maintenance and Manufacturing at Tronosjet Manufacturing. “We knew that additive manufacturing could provide the required strength and that having our new bracket certified by the FAA would validate the use of additive in aerospace production.”

Challenge

For FAA certification, Tronosjet needed to demonstrate the quality, strength, and reliability of the printed parts. The regulatory body’s material scientists, aerospace engineers, and airworthiness specialists required extensive testing to ensure the bracket’s safety. This included tensile, fatigue, and non-destructive testing (NDT), as well as proof that the titanium alloy and manufacturing process were repeatable and reliable.

“Over the years, we have communicated with the FAA many times on different projects, and we understand how it works as a regulatory body,” added Campbell. “This gave us an advantage because we knew what to expect. We knew that we’d need to prove the bracket’s safety using tensile, fatigue, and NDT testing, and to show that it wouldn’t degrade over time.” To meet these requirements, Tronosjet turned to Renishaw, a global leader in engineering technologies. The company needed a high-quality AM system capable of producing complex metallic components with precision and consistency—key attributes shared with hydraulic and pneumatic systems that operate under extreme conditions.

Solution

“Our relationship with Renishaw goes way back, and we first came to the UK to meet with its CEO in 2018,” explained Campbell. “The reason we decided to go for a Renishaw system is the brand—it’s a trust marker, and we knew it was a company that offers excellent engineering and process capability. Its RenAM 500 series are world-class AM machines, and of the quality we needed to achieve FAA certification.”

Tronosjet purchased three RenAM series machines from Renishaw: the AM250, the 500S Flex, and the 500Q. All three machines use laser powder bed fusion (LPBF) technology for metal component production and feature a build volume of 250 mm x 250 mm x 350 mm. The AM250, a single-laser system, was selected to produce the thrust control pulley bracket due to its ability to produce parts with high material properties that meet FAA standards. Notably, the decision to avoid multiple lasers or recycled powder reflected a cautious approach to align with FAA expectations.

Using the AM250, Tronosjet printed the bracket from a Ti-6Al-4V titanium alloy. Titanium’s high strength-to-weight ratio and corrosion resistance make it a popular choice for aerospace components, as well as for high-pressure hydraulic and pneumatic systems.

Result

After extensive testing, the titanium bracket proved to be five times stronger than the original magnesium part. It survived loads exceeding 22,000 lb, compared to the original’s failure at 4,000 lb. The part underwent rigorous NDT, static, functional, and destructive testing to validate its performance, convincing FAA regulators of its safety and reliability.

“The numbers put things into perspective,” continued Campbell. “The bracket’s superior tensile strength shows that the titanium print is capable of withstanding significantly higher loads than required when the aircraft is in flight. This helped convince the regulators that AM was more than up to the job.”

The FAA certified the bracket under its Parts Manufacturer Approval (PMA) programme, making it one of the first FAA-certified metallic AM components. Certification allows Tronosjet to produce and supply the part to customers, providing a competitive edge in the aerospace market.

Implications for hydraulic and pneumatic systems

The success of Tronosjet’s additive manufacturing process signals broader opportunities for using AM to produce highly customised components for hydraulic and pneumatic systems. Lightweight manifolds, intricate valve systems, and pressure-resistant housings could all benefit from the precision and material properties achievable through LPBF technology. As regulatory bodies continue to recognise the reliability of AM parts, its application in fluid power systems for aerospace and other industries will likely expand.

For further information please visit: www.renishaw.com

https://twitter.com/renishawplc

https://www.linkedin.com/company/renishaw/