An aircraft’s landing gear is carefully and strategically designed to safely ascend and descend the aircraft. Bushings — metal bearings within landing gear that allow it to move with minimal friction — prevents wear on the costly components, even while exposed to extreme environments. Marsh Brothers (MB) Aviation is an Ontario-based company that has been designing, testing and manufacturing high performance bushings, bearings, seals and other mechanical components for the aviation industry for over a century. They engage with diverse global markets to develop and deliver innovative light-weight non-metallic self-lubricating bearing and sealing solutions for the commercial and general aviation markets; improving aircraft reliability and maintainability, while reducing its environmental impact.
One of the latest innovations by MB Aviation is their AeroTough® GF (ATGF), a proprietary self-lubricating polymer from which they design and manufacture grease-free bearing components. With lubrication built into the polymer formulation itself, ATGF bushings can reduce aircraft maintenance costs drastically as no grease or oil is required for their operation, also eliminating bushing corrosion.
To help MB Aviation validate this self-lubricating polymeric bushing technology, they partnered with Centennial Innovates - the Applied Research, Innovation and Entrepreneurship (ARIES) department at Centennial College - and Safran Landing Systems, the world leader in aircraft landing and braking systems, to test and validate three different types of bushings for aerospace applications.
For Centennial College, this project strengthened an ongoing collaborative relationship with MBA built over 5 years working together to validate MB Aviation’s polymeric bearing technology for larger commercial aircraft application. In this project titled “Engineered polymer dynamic load and wear characterization”, the Centennial team started with the leadership of the Principal Investigator Florin Nijloveanu, professor at Centennial College School of Engineering, Technology and Applied Sciences (SETAS) with in-depth expertise in Mechanical Engineering and broad experience leading applied research projects. In addition to working with MB Aviation, Professor Nijloveanu had worked collaboratively with many other major aerospace companies such as Safran Landing Systems, Bombardier Aerospace and Lynch Fluid Controls, and brought his experience designing custom applied research test rigs to validate technologies in suitable environments to this project. During Spring this year, the project was passed to professor Charanpreet Sidhu, also professor at SETAS, Master in Mechanical Engineering, with expertise in part modelling and simulation on software like SolidWorks, Catia, and Ansys. As with any applied research project at Centennial Innovates, student researchers were at the heart of the project. This project engaged 6 student researchers: Akansha Nagar, Bipul Jha, Sanaa Bayi, Jorge Corichi, Jarid Robertson and Jeffrey Valenton – the latter two of whom recently graduated.
All three current student researchers Nagar, Jha and Bayi had positive comments to share about their experience. “I was very interested in aerospace from a very early age. My aim is actually to get into research in aerospace, but I didn’t know how to do research. Like, with whom do you do it? How do you do it? You need a lot of hands-on practice. That’s how I got into this opportunity.” shared Jha, an international student from Nepal in the Aerospace Manufacturing Engineering Technology program. He became a student researcher at Centennial Innovates to gain practical experience doing research, with this being his first project. He was very enthusiastic to share the impact of his experience. “Here, we are learning the tools, we are learning the machines. We learn about them in our courses, but with ARIES, I am getting the hands-on experience. In my project, I am using the MTS machine right now. That machine is an industry standard for stress and tortional test, any test involving compression, tension, and torsion. We had a basic course on how the machine works, but right now I know how to operate the machine. I am very happy because I am learning a lot. I am also talking to other professors, who teach me what they do in the industry. These things are not in the books, it’s what you learn from experience. I’m learning from other people’s experience and that’s something I’m very grateful for.”
The goal of the project was to validate their bushings for use on the Piper Aerostar, a 2-tonne transportation aircraft designed to withstand high speeds and loads. Specifically, MBA sought to test their polymer and rigid metal bushings manufactured for high strength and minimal chemical resistance. The Centennial College researchers collaborated with MBA’s engineering team and Safran Landing Systems to identify suitable landing gear bushings where ATGF could replace traditional metallic bushings as well as to design and build a test rig where application-specific testing could be conducted to validate the suitability of ATGF in higher load applications.
"My responsibilities in this project include conducting tests, collecting data and collaborating with a team of researchers to acknowledge the results. I have learned how to work collaboratively with a group of researchers,” explained Bayi, another student researcher in the Aerospace Manufacturing Engineering Technician program. “It's really an exciting opportunity to explore details of airspace components and contribute to advancements that elevate safety and performance in aviation. This project is not just about addressing existing problems. It's about actively seeking innovation and learning. The dynamic nature of our work emphasizes continuous learning, and it's incredibly rewarding to be a part of team that follows adaptability and growth."
Indeed, the bushing’s innovative potential and implementation brings about excitement to the student researchers. "This project is very important because with these bushings, they lubricate themselves. They can reduce the maintenance cost as well as maintenance time, and they last longer meaning they are less likely to be replaced, so it’s good for the environment as well." Jha went on to explain their testing in more detail. "One of our tests is, how long does it last? We calculate how much wear [the bushings take], and from that we can predict how long it’s going to last. So, these bushings are very innovative and very important for the industry."
"In the spirit of global manufacturing and innovation, it’s a more sustainable approach to do it right, not do it twice,” added student researcher Nagar in the Mechanical Engineering Technology Design – Fast Track program. "That’s why we’re not wasting any resources and instead doing the necessary testing, so that we come out with a product that the client and we as researchers are very proud to test and explore with." This mindset, she explained, is one that the Centennial Innovates team consistently inspires in their student researchers. "I think it’s really cool that we’re contributing to this approach, it’s not a performative approach but something integrated and always at the forefront of when we design, do testing, or use materials throughout the whole project, something we always consider. Being a part of this iterative approach is actually such a valuable experience."
The project is still ongoing and is scheduled to be completed by mid-December this year. So far, Centennial students and faculty built a custom test rig and tested 4 bushing configurations to determine their a) static coefficient of friction, b) dynamic coefficient of friction, c) wear rate under dynamic loads, d) maximum dynamic load and e) maximum static load. To design the test rig, iterative and concurrent design practices were used to ensure that all specified speeds and loads were met. To conduct the tests, the test rig is attached to the MTS (Materials Test Systems) Machine to deliver variable loads to the bushings in compression. The theoretical and actual results from iterative compression and torque testing are then explored to help verify the structural integrity of their bushings on the Aerostar’s landing gear.
The value of this project cannot be defined only by the results of the testing for MBA, but also by the development of essential skills and innovation mindset within the student researchers which they will take with them into future projects, careers, and their lifelong endeavors. As Bayi further expressed, "My involvement in this project has been crucial for the development of various skills. For instance, this project has provided hands-on experience in conducting tests and data analysis, significantly enhancing my technical skills. I’m learning how to conduct testing on the MTS machine to tell the characteristics of the bushings, which are very important skills to learn in the aerospace and mechanical industries, and engineering in general. We are also continuously learning how to work with different software such as Siemens NX and Mastercam, and how to collect data and write reports, improving our skills every time. Moreover, collaborating closely with a diverse team of researchers not only improved my communication skills, but also exposed me to various perspectives and learning and problem-solving as a result of our troubleshooting sessions. As I pursue my long-term goal of becoming aerospace engineer, this project has deepened my passion for aviation and has solidified my commitment to making positive impact in this field."
In addition to technical and soft skills, Nagar also commented on the mindset she gained while working on this project. "Design for intent is a big ideology that a lot of engineering professionals need to keep in mind." She explained how her experience in this project directly helped her secure a co-op position recently. "I was fortunate to present the research from this project with my team at one of the Ontario Aerospace Council Research & Technology Days, which led me to new networking opportunities. Employers saw me having the technical skills as well as the training and first-hand experience in developing a product from start to finish, with sustainability in mind, quality in mind, and meeting the requirements of the company. I owe a lot of credit to [Centennial Innovates] and this project for my coop position."