Aviation could save money, downtime and spare parts by a switch from preventive maintenance to condition-based maintenance (CBM). Bruno Santos is coordinator of the 6.8 million euro project that will develop a roadmap towards CBM, as well as work on the required technology. “It is not a question of if, but when CBM is coming. It is the future in aircraft maintenance”, says Santos.

Currently, conservative design practices are part and parcel of aviation safety. “We don’t have real-time insight into the condition of aircraft components, so we design for safety. Redundancy means an aeroplane carries twice the number of systems it needs. Also, the structural design is heavier than it has to be”, explains Assistant Professor Bruno Santos of the department of Control and Operations. However, aircraft are already equipped with thousands of sensors that can report on the condition of components. By adding sensors that monitor the structural integrity, a full picture of an aircraft’s condition can be obtained, opening the way for condition-based interventions to replace the current practice of preventive maintenance.

CBM has many benefits

Such condition-based maintenance could make aviation financial, socially and environmentally more sustainable. “If we only carry out maintenance when it is needed, we can exploit the full lifetime of components. Moreover, if we have insight into the actual state of health of components and structures, we could relax our design protocols somewhat. And lighter aircraft consume less fuel and produce less emissions.” Less material, less fuel and less emissions are good for the environment, but CBM has more benefits. “With CBM we would be able to intervene just before an aircraft develops a problem, so passengers should experience less technical delays, and airlines would be more reliable in their service”, Santos explains. Then there are the financial benefits. Less spare parts, less downtime, less maintenance and less fuel: the savings add up. It is estimated that CBM could save the European aviation sector alone some 700 million euro’s per year.

Exploring the feasibility of new technology

The idea for ReMAP came from a group of four researchers from the Faculty of Aerospace Engineering: Bruno Santos himself, Wim Verhagen and Mihaela Mitici from the group of Air Transport and Operations and Dimitrios Zarouchas from the Structural Integrity & Composites group. They applied under a call for an H2020 Research and Innovations Action (RIA), aimed at establishing new knowledge and exploring the feasibility of new technology. “That fitted very well with what we had in mind, so we streamlined our initial ideas, and started contacting partners”, says Santos. “That can be nerve-racking, because you want to share your vision, but you don’t want to give away too much, as they might be competing with you on another proposal.” Luckily, those fears proved unfounded. “Almost everyone we contacted, came on board straight away.”

A roadmap towards CBM

The consortium includes airline KLM, aircraft manufacturer Embraer Portugal, IT company ATOS, and UTC, the world’s largest manufacturer of on-board systems. “The reaction of our partners validated our vision: CMD is the future of aircraft maintenance. Some of our partners were happy to be part of the project, because they share that idea of the future, and want to be on the cutting edge. Other, smaller enterprises, and research institutes see it as an opportunity. Really, the question is not if, but when and to what extent CBM is going to happen, and that is part of our research questions.” One of the deliverables of the project is a roadmap toward CBM.

Defining specifications and requirements

With the project still in its first year, there are not a lot of concrete results yet. “We are at the stage of defining the specifications and requirements, and developing the initial algorithms.” Santos is a specialist in developing decision support tools. “We have partners developing tools that can determine which parts are about to fail, based on sensor data. We are developing a maintenance planning tool,an algorithm that uses that information to determine which plane should receive maintenance today, and which ones can wait until next week, for example.” Also, serious discussions are under way on the architecture of the IT structure. “A reliable health monitoring process cannot be based on data from just your own fleet of aircraft. Airlines will have to agree to some sort of data-sharing, so they can benefit from data coming from the same type of aircraft from other airlines”, Santos explains. With airlines averse to sharing valuable business data, a new solution is now being researched. “During one of our workshops, we came up with the idea of a hub-and-spoke configuration, meaning algorithms can access and learn from the data from various airlines, without sharing the data itself.”

Being a coordinator is a challenge

Santos was asked to take the lead in the project by one of the full professors involved in the research. “I saw it as a challenge. It is unusual for an Assistant Professor to coordinate that kind of project; it’s not part of our job description. It helps there are four of us in the same project, with each of us supervising a PhD student.” As scientific coordinator, Santos has to keep the overall perspective. “I have to check that we deliver what we defined in the proposal, and have now put down in the consortium agreement. I am also the one who leads any discussions in the steering committee on changes in the content of the project, or the way the funding is spent. You have some leeway there in H2020. For instance, as long as the overall budget doesn’t change, you can discuss shifting funds from one work package to another, or convert the buying of materials into extra person-months, and so on.”

Pleased with the assistance from VC

Santos is also first point of contact for all partners. “I know all of them, so they address their questions to me, but the Valorisation Centre helps me with practical, financial or legal matters. I only have to take care of the science questions”, Santos says. He also gets help preparing the meetings with all partners that are organised every six months. “The prepare the agenda and write minutes and take care of other such time-consuming issues. They also keep track of the due dates of deliverables and milestones, and when to enter information on the EU Participants Portal. So far, I am very pleased with their assistance, and it also helps that they are just across the campus if you want to meet with them.”

Intellectual Property has to be resolved beforehand

An important aspect of the project is Intellectual Property (IP). “We are developing a lot of new technology, and we have many partners who want to make use of that, so these issues have to be resolved beforehand,” says Santos. “That means we have to come to some agreement of where we want to be in four years’ time, so in a way this also helps us in the discussion of what we are going to develop.” Santos doesn’t mind straying so far from his research. “These legal matters are not every researcher’s cup of tea, but I find it an interesting side of our jobs. So far, our partners have been proactive and open in this discussion and not the kind of hard-negotiating companies that won’t move from their requirements.” All in all, he finds being a coordinator a good learning experience. “I am still learning how best to manage my time, although I am getting better at it. It takes at least a day per week, though not necessarily on a single day. It also fluctuates, with peak times, and times when things go smoothly.”

Managing people and their expectations

Perhaps the most fascinating aspect is people management. “I like this aspect of managing people and their expectations. You have to be aware of group dynamics. Try to understand what every partner wants, and make sure they all feel part of the project”, Santos advises. “You also have to be a good listener. Sometimes partners are interested in other things than their contribution to the proposal would suggest, or they want something that goes beyond the proposal. You have to be aware of that and try to keep them engaged. A trade-off usually works: agree to help them after they have delivered their contribution to the project. I learned that from a colleague, and it was a very good lesson.”

It helps develop your research portfolio

At the end of the day, the science remains his priority. “It is exciting to do this kind of work, but only if you can still be a researcher at the same time. We are not meant to be fulltime project managers.” Here too, being a coordinator has its advantages, though. ”First, you are the owner of the core idea of the project, and that is aligned to your personal research goal. So these European projects can really help you to develop your own research portfolio. Also, as coordinator you have more say in the orientation of the project.”. Meanwhile, things are looking rosy for CBM. “This is already the second European project on that subject, and we are the leading European research institute on developing decision support tools for aircraft maintenance. We will continue to work on that after ReMAP”, Santos says. “We all know that CBM will be the future, and it is good to be part of that.”

Condition-based maintenance at a glance