Category: Avionics

What does it mean to be sustainable? Well, according to the United Nations Brundtland Commission, sustainability is defined as “meeting the needs of the present without compromising the ability of future generations to meet their own needs.” Hence, when it comes to MROs and their suppliers, being sustainable means serving their customers today while reducing their impact on the environment over time.

So, how does this form of sustainability translate into action? To find out, Aviation Maintenance consulted MROs and their suppliers who are taking steps to be sustainable. Their actions provide a roadmap for others in the industry to become sustainable themselves.

How Two MROs Are Becoming More Sustainable

MROs AJW Technique and Lufthansa Technik are both actively pursuing sustainability today. And they are doing so in concrete, practical ways that are delivering results right now.

Let’s start with AJW Technique. In a general sense, “AJW is driving sustainability by implementing more environmentally friendly products and practices into our operations,” said Louis Mallette, the company’s SVP Operations. “The inclusion of sustainable alternatives in our warehouses, such as eco-friendly packaging tape and materials, showcases our dedication to minimizing our environmental impact. This choice not only reduces waste but also aligns with the broader goal of creating a greener aviation industry.”

On the plant floor, “we are exploring innovations in materials used in the operations at our MRO facilities in Montreal, Canada, and Slinfold, U.K.,, ensuring the entire life cycle of aviation components is eco-friendly,” said Mallette. “This involves initiatives like recycling, repurposing, or using materials with lower environmental impact. We select and use the most eco-friendly alternatives available for chemical products, whilst ensuring these are equivalent to the materials used by the OEM and are OEM approved. Where parts cannot be repaired or re-used and disposal is necessary, we ensure segregation of materials to maximize recycling opportunities.”

Electricity consumption is another area where AJW is working to become more sustainable. They’re lucky to have a built-in head start in this area: “Our AJW Technique facility in Montreal is located in Quebec, Canada, where virtually 100% of electrical power is generated from renewable sources (primarily hydro power), making it the ideal location for Technique’s more energy intensive activities,” Mallette said.

Even with this advantage, AJW Technique is continuously reviewing opportunities to reduce its energy consumption. “Recent examples include the full retrofit of lighting at our 220,000 square foot facility, and the replacement of our air compressors, which were notably oversized for the requirement with optimized units to meet our needs,” said Mallette. “Both energy saving practices have resulted in a significant reduction in energy usage in the facility.”

Becoming more sustainable also means reducing carbon dioxide (CO2) emissions. To this end, AJW’s Montreal headquarters has installed a rainwater harvesting system and solar panels at the facility. These efforts and other efforts have reduced AJW’s annual CO2 emissions by 425 tonnes. “Alongside this, we are well on the way to powering AJW Technique Europe (in Slinfold, UK) with solar energy, enabling the Battery Centre of Excellence to recharge aircraft batteries sustainably,” Mallette said. “We also take numerous measures to reduce operational power usage including scheduling plants and machinery to turn off when not in use and utilizing PIR (Passive Infrared) sensors on office lighting, which are set to the lowest timer.”

In a bid to expand sustainability beyond AJW’s four walls, this MRO’s Procurement Teams actively seek suppliers and partners who share similar sustainability principles. “Collaborating with like-minded partners ensures a more comprehensive approach to sustainability throughout our business operations,” Mallette said. “It’s not just about the product but about the entire process leading to it.”

AJW Technique is even applying sustainability to its housekeeping services by seeking more environmentally friendly cleaning solutions in its MRO facilities in Canada and Europe. “The use of aqueous cleaning agents wherever possible is standard practice within our facilities,” said Mallette. “Sustainable cleaning products contribute to a healthier environment and align with our commitment to the United Nations Global Compact (UNGC).”

The bottom line: When it comes to becoming more sustainable, AJW Technique is ‘walking the talk’ across its entire operation — positioning this company as a leader in fostering sustainability within the aviation sector.

Headquartered in Hamburg, Germany, with MRO facilities around the globe, Lufthansa Technik is equally committed to becoming more sustainable. “To enhance efficiency and conserve resources, we have integrated various products, practices, and solutions into our own operations,” said company spokesperson Lea Klinge. “Our commitment encompasses the implementation of energy-efficient facilities, waste reduction initiatives, and recycling programs within our maintenance processes.”

Another environmentally conscious solution developed by Lufthansa Technik (LHT) is its ‘Cyclean’ aircraft engine wash. “A cleaner engine operates more efficiently, requiring less fuel and maintenance, contributing to environmental preservation,” Klinge said. “Lufthansa Technik’s Cyclean Engine Wash system injects vaporized hot water directly into the core engine, effectively removing combustion residues and contaminants. Regular use of this system leads to a notable reduction in fuel consumption, cutting up to 80 metric tons of CO2 emissions per aircraft annually. Furthermore, customers benefit from increased on-wing time and decreased maintenance costs.” One nice feature: LHT ensures the clean and safe disposal of all wastewater generated by the Cyclean process, she noted, without causing any adverse effects on the environment.

LHT is also working to extend sustainability to the aviation world as a whole. To this end, this company provides MRO solutions that help its clients in minimizing their environmental footprints. “This includes innovative products like AeroSHARK, a bionic film developed in collaboration with BASF,” said Klinge. “AeroSHARK, featuring ‘riblets’ inspired by sharkskin, can be easily applied to large areas of commercial aircraft surfaces. By reducing the aerodynamic drag, this technology significantly reduces fuel consumption and emissions. Our observations on Boeing 777s treated with the currently certified expansion stage of the AeroSHARK modification already indicate a one percent reduction in fuel consumption, and initial calculations suggest potential savings of up to three percent at its maximum expansion level.”

What Suppliers Are Doing To Help

Aerogility and Aerotrax Technologies are two aviation suppliers who are supporting sustainability in their own right.

With offices in Atlanta and London, Aerogility uses model-based AI and enterprise digital twin technology to give aircraft operators a holistic overview of their operations. Its sector-specific AI models allow fleet and maintenance planners to simulate real-world scenarios to generate reliable insights for forecasting, planning and decision making. “The simulations can be used to assess the impact of a scenario and why the AI technology made a particular decision before they are implemented,” said Phil Cole, Aerogility’s airline business manager. “This can include the impact of bringing in a new fleet, changing maintenance schedules, or introducing sustainable aviation fuels (SAF).”

Aerotrax Technologies is a Dallas, Texas-based enterprise software company focused on data sharing and visibility in the aviation/aerospace supply chain. “We are a cloud-based software vendor, so the delivery of our products has negligible impact on the environment,” said David Bettenhausen, the company’s founder and CEO. “By focusing on small improvements on a daily basis, we drive positive, incremental change across the supply chain organization — which, as a business function, is the beating heart that drives all aftermarket success.”

In addition to helping its clients become more sustainable, Aerotrax is applying sustainability to itself. “We run a lean operation, continuously looking for ways to be more efficient,” Bettenhausen said. “When sustainability is embedded in your culture, it’s the little things that you commend. Whether it’s rearchitecting the system design from a blockchain-based, energy intensive platform to a serverless, pure cloud implementation, or if it’s prioritizing flight choices based on total carbon emissions rather than only convenience or only price as the sole decision-making driver — we are constantly holding ourselves accountable to our own internal bar. In both these decisions, our software and our people are able to perform better.”

“The picture I’m trying to paint is that sustainability is multi-faceted,” he added. “No single pledge, policy, product, or person automatically makes an organization sustainable. It’s the little things that are done on a daily basis. I also personally do not believe it is wise to look at sustainability in a vacuum of environmental sustainability, which is oftentimes the case. The most thoughtful decisions in this context artfully balance environmental and economic alignment in both the short term and long term.”

Airlines Want Sustainable MRO Solutions

There is no doubt that becoming more sustainable is a responsible social policy for MROs. But it is also good business. This is because airlines and other aircraft operators want to be more sustainable to satisfy environmentally conscious customers who pay their bills, and the governments that regulate their industry.

“Passengers are the lifeblood of our industry, and if operators do not listen to the needs of their customers, they may opt for a greener airline,” said AJW’s Mallette. “Our customers, being operators and those supplying operators, are looking for MRO operations that feed into their sustainability goals.”

“We are seeing a growing demand for more sustainable MRO solutions from our clients,” agreed LHT’s Klinge. “Airlines and aircraft operators are increasingly focused on reducing their environmental impact and operating more sustainably. This has led to a greater interest in MRO solutions that can help them achieve their sustainability goals.”

There are other ways that MROs can become more sustainable, at least from a regulatory standpoint. For instance, airlines have been strong buyers in the Carbon Credit markets to offset their CO2 emissions. “I have some friends over at Green Trade Solutions in the U.K., who have been supporting big, new carbon capture projects and helping airlines find projects they can get excited about that are in line with regulatory requirements,” Bettenhausen said. “While the MRO industry certainly recognizes the importance of sustainability, I haven’t seen as much activity or appetite for these carbon offset initiatives in the same way that I see airlines pursuing.”

A Necessary Commitment

“According to NOAA’s 2023 Annual Climate Report the combined land and ocean temperature has increased at an average rate of 0.11° Fahrenheit (0.06° Celsius) per decade since 1850, or about 2° F in total,” said the U.S. government website climate.gov (full link at end of article). “The rate of warming since 1982 is more than three times as fast: 0.36° F (0.20° C) per decade.”

With facts like these, there is no doubt that industry needs to take climate change seriously and address it through sustainability initiatives. “In 2022 aviation accounted for 2% of global energy-related CO2 emissions, having grown faster in recent decades than rail, road or shipping,” said the intergovernmental International Energy Agency at www.iea.org (full link at end of article). “Many technical measures related to low-emission fuels, improvements in airframes and engines, operational optimization and demand restraint solutions are needed to curb growth in emissions and ultimately reduce them this decade in order to get on track with the Net Zero Emissions by 2050 (NZE) Scenario.”

LHT takes its role in addressing climate change seriously. “It is vital for every company in the industry to use or even offer solutions for a more sustainable aviation,” Klinge said. “For us, this also means to engage in research activities that provide important impulses for a carbon-neutral and potentially hydrogen-powered future. To investigate the effects of the use of liquid hydrogen (LH2) on maintenance and ground processes already at an early stage, and to provide valuable impulses for the designers of future aircraft, Lufthansa Technik is partnering with renown research and industry institutions and will jointly operate a comprehensive LH2 field laboratory based on a decommissioned Airbus A320.”

The good news? In a very fundamental sense, “MRO and sustainability are actually quite harmonious concepts,” said Bettenhausen. “By choosing to maintain, repair or overhaul a part, purchasing managers are actually choosing the more sustainable solution than buying new. (In the Defense world, MRO is literally called Sustainment.) If we continue to find novel ways to extend the life of parts and aircraft — from more accurate aftermarket measurement and reporting, to feedback loops and data sharing with OEMs, to new breakthroughs in material and systems design — we can move the needle on ambitious sustainability goals. I believe these innovations are imperative to ensure the long-term economic health of the industry.”

The Big Picture

By actively pursuing sustainability, MROs and their suppliers are aligning themselves with the aviation industry as a whole, where achieving sustainability has become a priority. After all, being held responsible for 2% of global energy-related CO2 emissions is not a good position for any industry, whether on a social, environmental, or regulatory level.

“This is why “the International Civil Aviation Organization (ICAO) set a goal in October 2022 to achieve net-zero carbon dioxide emissions from aviation by 2050, prompting a shift towards sustainability in the aviation sector,” Mallette said. “If we are to ensure the economic health of our industry going forward, MROs such as AJW Technique must adopt and provide sustainable solutions within their business and MRO operations. The world and passengers are demanding it from the industry.”

“As the aviation industry continues to focus on sustainability and environmental responsibility, MROs that can offer innovative and more eco-friendly solutions will be well positioned to attract and retain clients,” added Klinge. “Additionally, sustainable practices can lead to improved operational efficiency and long-term cost savings.”

A case in point: “By using safe and trusted AI solutions, MROs can model carbon outputs for example, enabling them to meet carbon emissions targets,” Cole said. “MROs and airline maintenance departments can also use the insights generated by AI to efficiently implement optimized maintenance schedules, reducing unnecessary part wastage or aircrafts operating without the latest emission-reducing technologies.”

If there is a lesson to be drawn, it is that sustainability is a necessary commitment for the MRO industry, and a requirement that will shape its economic viability going forward. Thankfully, the sincere efforts of the MROs and suppliers noted above, along with those of others in the aviation industry, offer a good chance of delivering on this promise.

“Remaining economically viable in the MRO industry requires staying at the forefront of sustainable practices,” concluded Mallette. “Collaboration will drive the health of the industry while also protecting the planet and its people.”

The number of widebody commercial aircraft in the world is increasing, and so is the need for these aircraft and their engines to be serviced by MRO shops.

“We see the widebody fleet growing at about 2.6% over the next five years and widebody overall MRO growing at 3.9%,” said Derek Costanza, a partner in Oliver Wyman’s Aviation and Aerospace Practice. “Widebody engine MRO will approach 4.3%, and engines will represent almost 50% of the total MRO dollars spent in the next five years, so that brings up the average. Growth will come mostly from China and the Middle East.”

“For mature widebody engines such as the GE90, MRO demand has increased significantly in the past year and will continue to grow over the next few years as passenger flying returns to normal,” added Alistair Forbes, senior market analyst with the MRO MTU Maintenance. “These engines are very reliable, with the vast majority of shop visits being scheduled.”

At the same time, grasping the full profit potential of the widebody maintenance market is apparently out of reach for airframe and engine MROs. The reason: “The WB (widebody) MRO market recovery is slower due to slower recovery of long-haul traffic” after Covid-19, said the 2023 VZM Market Outlook for Commercial Aviation & Maintenance. But it could be worse: The pandemic also slowed down the production of new widebodies, forcing airlines to keep older aircraft like the A380 in service, it said. More older widebodies flying means more business for MROs, even with a slower-than-expected return to normal airline traffic levels.

“Airlines are struggling to get new widebody aircraft from Airbus and Boeing,” said Gilles Fossecave, CEO of the MRO Vallair. “That’s why they are asking for maintenance on their existing widebodies, in order to keep their fleets as large as possible and able to fly.”

The State of the Industry

There is no doubt that Covid-19 disrupted the growth of the world’s widebody aircraft fleet. According to Oliver Wyman’s ‘Global Fleet and MRO Market Forecast 2023–2033′ report (the Market Forecast report), “we project the worldwide commercial fleet to expand 33% to over 36,000 aircraft by 2033 — a compound annual growth rate of 2.9%. Today it numbers almost 27,400, just short of its size in January 2020 — the last month before Covid changed the economy and everyday lives around the globe.”

This report then observed, “while aviation is most assuredly on a growth trajectory after a devastating two years of losses, it’s currently carrying a lot of baggage that can’t be easily checked. With Covid-19 ostensibly behind us, the [airline] industry will be dealing with a series of new and old challenges over the next 10 years that will test its resilience and may temper how fast it continues to expand.” The same is true for the MROs that serve them.

Let’s look at these challenges in depth.

The Impact of Slowed Widebody Production

When Covid hit in 2020, airlines delayed their widebody purchases with Airbus and Boeing in order to save money. “The greatly reduced levels of passenger traffic impaired airlines’ ability to pay for aircraft and so they often requested deferred delivery dates,” explained Forbes. This, in turn, slowed widebody production, which put the OEMs and airlines in ‘catchup’ mode once the crisis eased and normal air travel started to resume.

The same penny-pinching mentality also guided airlines’ approach to widebody maintenance during the worst of the pandemic. “I think all the airlines in the world were trying to save cash as much as they could,” said Derk Nieuwenhuijze. head of strategy, marketing and communication with Air France Industries KLM Engineering & Maintenance (AFI KLM E&M). “So they postponed their narrowbody and widebody maintenance as much as they could.”

But there were a few exceptions: “Widebody MRO for the GE90-115B and CF6-80C2 engines remained strong during the pandemic, driven by the cargo market,” MTU’s Forbes noted. “Other engines that mainly catered to the passenger market suffered much larger MRO demand reductions, particularly for older less efficient aircraft.”

Even today, the impact of Covid-19 lingers on. “We expect an average of 240 new widebodies to be produced each year over the next five years, which is considerably lower than the annual average of 370 produced across 2018 and 2019,” said Costanza. “We do not see widebody production recovering to 2018/2019 levels until the end of the decade.”

The Impact on Widebody MROs

As mentioned above, the slowdown in new widebody deliveries has forced airlines to keep their older widebodies in service longer. The result: “Lack of widebody replacement definitely has created more MRO demand,” Costanza said.

Demand for widebody maintenance services is likely to increase further when world airline travel matches and then exceeds pre-pandemic levels. “This is one reason why MTU is confident that we will continue to see strong widebody growth over the next few years as passenger activity returns to the long-term growth trend,” said Forbes.

This said, there are a number of post-pandemic problems that are taking the bloom off this particular rose. One of these problems is inflation, which is affecting all aspects of MRO operations.

“Inflation is a huge issue for all MROs,” Constanza said. “Depending on the parts, inflation has been right about the double-digit level. The trouble is that many airline operators cannot afford those increases while many MROs are trapped in contracts that limit price escalation due to inflation, so yes, it’s a big issue for everyone involved. In response, airlines and MROs have opened up to using more USM (used serviceable material) and PMA (parts manufacturer approval) parts rather than new OEM parts, but the historical savings are not there due to increased buyer demand.”

Inflation is also driving up labor costs, due to “consumer inflation leading to demands for higher wages across the supply chain,” said Nieuwenhuijze. “This is affecting everyone from the mechanics who are working on the aircraft to the people who make the parts, and those who gather the raw materials that these parts are built from.”

Then there’s the costs of keeping the lights on and the MRO hangars heated, which also keeps going up. At MTU Maintenance, “Energy is one of the drivers for cost increases, especially at our German locations,” Forbes said. “Further, we have experienced increased cost for material and outside vendor services, both reflecting the overall inflation trend in combination with scarce resources — the latter being driven by worldwide capacity adaptations in the supply chain and caused by Covid-19. Naturally, the share of material cost represents a major portion of our maintenance services and is therefore a significant driver for overall cost increase.”

In a bid to drive down at least some of these inflationary costs, MTU is investing in self-sustainable energy infrastructure such as photovoltaic technology and dual-use heat pumps. “These measures do not only help to better manage energy cost but also support MTU’s strategy towards a lower carbon footprint,” said Forbes.

Unfortunately, the only way for MROs to survive rising costs and stay in business is to pass on those costs on to their widebody customers. According to Vallair’s Fossecave, raising prices is a necessary move, but not a popular one. “Some airline customers don’t understand why prices have gone up to service widebodies, and we have to explain it to them,” he said. “Other airlines do understand, but they don’t like it because they have inflationary issues of their own to deal with.”

Supply Chain Issues Remain

Supply chains were seriously disrupted when the pandemic hit in 2020, and they have yet to fully recover. This is why “Supply chain challenges have hindered aerospace production lines, causing both Airbus and Boeing to fall short of production and delivery targets for 2022,” said the Market Forecast Report. “2023 is unlikely to be different for either, given that the two rely on many of the same suppliers and sources of raw materials, and the conditions remain about the same this year. Of course, many of the same parts are used on the A320 and Boeing 737, meaning that the pressure on some suppliers is multiplied.”

“For the older widebodies, the challenge is always getting parts,” Costanza observed. “For these older widebodies, engine maintenance continues to be a particular challenge as does landing gear, both of which are very dependent on the OEMs.”

“A strained supply chain is an issue that is currently affecting the entire industry, including OEMs, MROs and suppliers,” said Forbes. “At MTU, we are working closely across our entire network and in all regions to limit the impact on customers as much as possible.

As for the immediate future? “Supply chain issues will limit OEMs’ ability to ramp up production quickly to match the rapidly rising demand from airlines,” said Alton Aviation Consultancy’s ‘Skyward Bound: 2023-2033 Commercial Aircraft and Engine Fleet Forecast’. “As a result, OEMs have substantial order backlogs which stretch until late in this decade for most of the popular in-production aircraft families. It is not expected that OEMs will bring into service additional new cleansheet aircraft designs in this decade beyond the 777X, despite industry sustainability commitments.”

Ironically, the only reason this situation isn’t worse is due to the current level of widebody flights. They still haven’t recovered from Covid-19 either.

“At a global level, the amount of widebody flying in Q3 this year was only 92% of the Q3 2019 level (with Q3 usually being the busiest quarter of the year for flying), so the widebody market overall still has a little way to go to get back to pre-pandemic levels of flying,” Forbes said. “This shortfall is even more marked if you consider that the market was growing quickly before the pandemic hit. If 2019’s flying had continued to grow 4% per year, we would have had global flying at 117% of 2019 levels this summer, so the 92% figure mentioned earlier reflects a significant reduction compared to where the market would have been without the pandemic.”

A Lack of Labor

It is difficult to service any aircraft if you don’t have the technicians on hand to do the work. This also applies to flying commercial airliners if you don’t have the pilots.

According to Oliver Wyman’s Market Forecast report, this one-two ‘lack of labor’ punch is knocking the entire aviation industry for a loop.

A case in point: “In North America, the industry is facing two potentially severe shortfalls in the ranks of commercial airline pilots and aircraft mechanics,” said the Market Forecast report. “By our analysis, the supply gaps will amount to 18% of the total pilot workforce in 2023 and 14% of aviation mechanics. The outlook is for those deficits to grow or at least linger through 2033. The gap between the number of pilots needed and those available has already led to reductions in service to less popular and more rural destinations and has hit regional airlines hardest.”

Worse yet, “the shortfall of aviation workers is a global problem,” the Market Forecast report continued. “European ground crew shortages were so ubiquitous and severe in 2022 they led to the imposition of capacity limits at some European airports, including London’s Heathrow and Amsterdam’s Schiphol. In India — the fastest-growing aviation market, according to our latest Fleet and MRO Forecast — the desperate need is for more air traffic controllers. But because so many aviation jobs are critical to operations, any ongoing shortage can eventually result in the industry’s growth being limited not by a lack of demand but by supply constraints.”

According to MTU’s Alistair Forbes, hiring enough qualified personnel and managing parts supplies are the two main challenges facing MROs today. “The skilled and experienced workforce shortage will be around for some time mirroring the demographic development — especially in the Western world,” he said. “MTU was fortunate enough to retain its workforce during Covid and we are now partnering with schools, colleges and universities to recruit and train new hires on a continual basis all over the world. We also continue to invest into our in-house mechanic apprentice programs and training centers: For instance, MTU Maintenance opened a dedicated training center at its facility MTU Maintenance Zhuhai earlier this year and announced its training academy, a collaboration with the British Columbia Institute of Technology, at MTU Maintenance Canada in Delta, BC.”

The Impact of Cargo Conversions

When passenger traffic fell off during the pandemic, many airlines converted their idle widebody airliners into cargo carriers, in a bid to capitalize on growing traffic in this area.

For a while this worked. But in 2022 “the cargo market started to soften while capacity increased further,” said the VZM Market Outlook 2023. During most of that year “demand was declining despite higher world trade than the year before,” it said. To make matters worse, “cargo revenues remained almost flat, supported by even higher yields than the previous year.”

As a result of these trends, VZM is not bullish about the air cargo market as a money-maker for airlines post-pandemic. “Air freight demand is expected to be weaker in 2023 but to recover in later years,” the VZM Market Outlook said. “Global cargo revenue will decrease 25% in 2023 but still be 50% above pre-corona revenues. [The] main reason is the still strong cargo yield expected in 2023, although also sharply declining. The weaker market is forcing cargo airlines to cut costs after very profitable corona years.”

So what does this mean for those MROs who convert widebody passenger aircraft to freight (P2F) carriers? “Over the next five years we expect widebody P2F conversions to double to an annual average of just below 40,” said Costanza. “This is about double what we have seen yearly since 2018. These conversions drive more demand for MRO services, but it’s fairly minimal in the context of the overall MRO market.”

“I would expect the demand for cargo conversions will be a little bit lower going forward than it has been,” Nieuwenhuijze said. “And I’m always a little bit skeptical about the importance of cargo conversions in the overall MRO market: Of course, the numbers we saw the past years were huge comparatively to what we’ve seen before. But as a whole, the cargo aircraft market is relatively small if you compare it to commercial airlines.”

The Bottom Line

Clearly, the widebody MRO industry is facing a number of challenges in the wake of Covid-19. However, these challenges don’t change the fact that global air travel is increasing, and on track to exceed pre-pandemic levels in the future.

As a result, “we see a huge appetite of airlines worldwide to buy new aircraft,” said Nieuwenhuijze. “So the world’s widebody and narrowbody fleets will grow quite significantly going forward. This means that MROs such as AFI KLM E&M will have to ramp up capacity. My only concern is that we will have enough suppliers to support us in our work, especially in the area of widebody engines.”

“The big challenge for airlines will be to find widebody MROs with enough available slots to service their aircraft in a timely manner,” Fossecave concluded. “Our challenge will be to find and retain sufficient skilled technicians to do the work.”

The days of aircraft composite repairs being unique and exotic are over. The popularity of carbon fiber and other composite materials in aircraft means that repairs to these structures are becoming standard procedures at MROs worldwide.

So, what kinds of composite repairs are common, what advances have been made to these repair techniques, and what future advances are coming? To find the answers to these and other questions that matter to MROs, Aviation Maintenance magazine spoke with three composite repair experts. They are Eitan Danan, head of the composites department at the IAI Bedek Aviation Group; Lorenzo Marandola, president of M1 Composites Technology; and Louis C. Dorworth, direct services division manager at Abaris Training Resources, which teaches technicians how to work with aircraft composite materials and perform repairs.

Common Composite Repairs

To put aircraft composite repairs into context, we began by asking about the most common aircraft composite repairs and the challenges associated with them.

At the IAI Bedek Aviation Group (IAI), “our focus is on repairing structural elements such as fuselage skins and wing structures that have been affected by wear and environmental factors,” said Eitan Danan. “The B-767-300 is the most commonly serviced aircraft in our hangars. IAI performs heavy maintenance for many airlines, which involves removing all interior components, including seats, galleys, lavatories and overhead bins, inspecting them and sending them to the composite or sheet metal shops.”

Finding damaged aircraft composites during maintenance inspections is a regular occurrence. To address them, IAI’s composite shop performs repairs in accordance with the structural repair manual, using hot bonder consoles, heat blankets, and vacuum bags. “In some cases, significant damage can occur during in-flight maintenance,” Danan said. “These repairs require engineering support and Boeing responds with structural composite repairs using advanced equipment and in-house expertise.”

Worth noting: Aircraft lavatories are often the most problematic areas encountered during composite repairs, due to severe corrosion on the lower metal fittings. To address this issue, IAI’s composite and sheet metal shops collaborate to manufacture new fittings and fasteners that adhere to the manufacturer’s technical specifications.

M1 Composites Technology’s expertise lies in composite structure repairs, with a focus on remedying common issues encountered in components like radomes and leading edges. “These repairs are often necessitated by factors such as bird strikes, hail, and environmental wear,” said Lorenzo Marandola.

As well, water penetration into aircraft composite materials and subsequent delamination are frequent problems that M1 addresses, particularly in nacelles and cowls subjected to significant vibration and stress. “To tackle these challenges, we employ advanced non-destructive testing (NDT) methods to identify areas of concern and undertake precise restoration work, often involving the careful removal and rebuilding of damaged sections to ensure optimal structural integrity and performance,” Marandola said.

To prepare MRO technicians to fix these and other aircraft composite repairs, Abaris Training Resources primarily teaches taper-scarf repair methods in their courses. “This is because these methods are preferred by original equipment manufacturers (OEMs) for a majority of composite structures and are called for in their structural repair manuals (SRMs),” said Dorworth.

When it comes to doing these repairs successfully, education is a must. “This is because problems mostly occur due to personnel that may have on-the-job training skills but greatly lack the fundamental knowledge required to be proficient with composite materials and processing,” Dorworth said. “Unlike metals that already have given mechanical properties, composite materials require that the properties of the patch are developed by choosing the right resin, orienting the fibers, and curing the resin/adhesive properly. This is where formal training fills the void, providing competent and confident mechanics and technicians that understand the underlying material and process knowledge necessary to provide airworthy repairs.”

Recent Advances

According to the experts, the science of aircraft composite repair has progressed considerably as composites have achieved widespread acceptance in the aviation industry.

“Recent years have seen notable advancements in repair equipment, particularly in terms of precision and control during the curing process of composite materials,” said Marandola. “With the shift towards larger aircraft structures constructed from composites, such as the A320 NEO and B737MAX, there has been an increased demand for autoclaves to effectively cure these components. These developments have enabled more precise and efficient repairs, ensuring the integrity and longevity of composite aircraft structures.”

According to Dorworth, the quality of adhesives, resins, and ‘prepregs’ (pre-impregnated materials) used in composite repairs is where the biggest advances have occurred over the last 20 years. These improvements support the use of lower temperature hot bonding processes, resulting in higher performance properties in the final repair. “Today’s focus is on achieving the best performance from cobonded repair patches for primary structures, versus what was acceptable for the secondary structures of yesteryear,” he said.

Ongoing Challenges

Even with advances in aircraft composite repairs, challenges remain.

A case in point: Detecting damage to composites that is not visible externally remains a significant challenge. “Consequently, ongoing research efforts are focused on developing improved methods for detecting heavy internal damage, which may be concealed from plain view,” said Marandola. “However, it’s worth noting that the OEMs responsible for designing and manufacturing these aircraft are best positioned to assess whether their assumptions regarding damage occurrence have been accurate. As they continue to gather data and refine their understanding of composite material behavior in real-world scenarios, insights gained from OEMs will be crucial for shaping future repair strategies and advancements.”

Being able to repair damage after it has been detected can also be a challenge. The reason? “As with everything, the original lab level studies that go into the repair design instructions do not always translate to the challenges found in the real world for many reasons,” Dorworth said. “Because of this, there have been a number of ‘issues’ that have popped up as new aircraft with carbon fiber reinforced polymeric (CFRP) structures have found their way into service. For the most part these challenges have been dealt with accordingly and are now mainstream.”

Then there’s the challenge of dealing with composite repair issues that are much larger than usually encountered. For example, there was the case of the Ethiopian Airlines 787 that experienced a battery fire in 2013. Fixing this Dreamliner required “a new piece of the composite fuselage to be fabricated, sectioned, and replaced at the upper aft section near the vertical stabilizer,” said Dorworth.

Of course, just the fact that composite materials are still comparatively new to aviation (compared to metal) explains why unexpected repair issues are still occurring. “As always, every time a new component or technology comes into the picture, it brings with it new problems and challenges,” Danan observed.

Tackling the Challenges

Fortunately for composite aircraft operators and owners, the companies interviewed for this article are taking action to address the repair challenges noted above, and many others. AT IAI, for instance, “we have developed comprehensive repair procedures, combining standard and innovative methods, focusing on international standards compliance and staff training,” said Danan.

The same is true for M1 Composites Technology. “Our company has undertaken several initiatives to develop repair procedures for composites,” Marandola said. “We utilize reverse engineering techniques to understand the original manufacturing processes and materials used in composite components. Additionally, we have assembled a specialized team of composite technicians and a dedicated engineering team with expertise in composites. Our extensive experience working on legacy platforms informs our approach to repairs on newer aircraft, allowing us to adapt and innovate effectively.”

This being said, finding ways to address composite repair challenges comes with challenges of its own. For example, “composite material properties are often proprietary to OEMs, making it challenging to ascertain original strength and manufacturing methods. As a result, substantiating repairs can be more complex,” said Marandola. “Moreover, the specialized tooling required for composite repairs, such as autoclaves, can be costly. Additionally, higher inspection and non-destructive testing (NDT) requirements further contribute to the challenges associated with composite repairs.”

To help MRO technicians successfully remedy composite issues through education, Abaris Training Resources has been working closely with organizations such as SAE/PRI and aircraft OEMs to develop relevant repair methods and standards for commercial/general aviation repairs. “We currently have a representative on the PRI Composite Repair Review Board, developing training and testing standards for aerospace composite repair technician certification,” Dorworth said. “In the past we have worked directly with OEMs in developing repair methods for higher altitudes over 8,000 feet. We have also worked with organizations and customers to develop and deploy repair methods within their own facilities by offering Repair Design, Analysis, and Substantiation courses to engineers.”

All this being said, our experts believe that composite aircraft OEMs could be doing more to improve the aircraft composite repair process.

One way OEMs could help is by standardizing repair procedures and materials across different aircraft platforms, which could significantly improve the efficiency and effectiveness of composite repairs. “Currently, variations in materials and procedures present challenges, as each material may have different characteristics and shelf life,” said Marandola. “By OEMs adopting common materials and procedures, MROs would be able to streamline their operations and reduce costs. Additionally, investing in the development of alternative materials that require less complex curing processes, such as heat blankets or room temperature cures, would simplify the repair process and increase flexibility.”

Another way is suggested by IAI’s Danan. “To simplify composite repairs, we propose creating a unified database of repair types based on SRM (structural repair manuals),” he said. “Based on our experience, we believe that this approach can expedite and streamline such repairs.”

If adopted, these suggestions would ensure that “MRO stations don’t have to stock different products and learn too many different methods,” said Dorworth. This would lead to faster and more affordable repairs.

What’s Coming

As exciting and innovative as today’s aircraft composite materials are, the future holds even greater possibilities — and new considerations for the MROs who will repair them. Here are some ideas from our experts about what is coming next.

“One promising area of development is the emergence of self-healing composites, offering the potential to autonomously repair minor damages and extend the lifespan of components,” Marandola said. “As well, additive manufacturing technologies present new opportunities for rapid prototyping and production of specialized repair parts, leveraging our existing capabilities in this field. Looking ahead, the future of composite repairs holds exciting possibilities, driven by advancements in materials and manufacturing processes.”

“Future developments will include a system based on global repair experiences that uses optical equipment for precise defect analysis and repair method selection,” predicted Danan.

“In addition to new and better performing materials and processes that evolve on almost a daily basis, there is a trend in aerospace design where quickly-formable thermoplastic composites (TPCs) are replacing standard thermoset composite structures in primary and secondary structures,” Dorworth said. “There are numerous efforts underway to develop repairs to TPCs as they will be necessary to the aerospace community within the next 5-10 years. In addition, machine builders are looking to automate many processes in repairs that are currently done by hand. This includes automatic taper-scarf machining, plasma surface treatment, and post-repair inspection using nondestructive methods.”

The bottom line: “The use of composites in aircraft structures is only going to increase in the coming years,” concluded Dorworth. “From our point of view, formal composite repair training is paramount to a new generation of competent aircraft mechanics in their effort to maintain airworthiness in every composite repair they perform. It is vital to the success of the industry.”

The landing gear MRO business is in a state of flux at the moment. With a typical overhaul interval of 10 years or 25,000 cycles, demand can be forecast with some accuracy based on historical aircraft delivery patterns. However, while the high utilization of low-cost carriers means that the period can be reduced to eight years, the pattern has been further distorted by many airlines having delayed maintenance during the pandemic but are now back flying at previous rates. As a result, demand is extremely high at the moment but, on the MRO side, companies are still facing post-Covid staff shortages and replacement training requirements as well as some supply chain issues, extending turnaround times. Looking further ahead, it seems likely that the 10-year limit may be extended to 12 years.

Revima

Olivier Legrand, group president and CEO of Revima, says the main facility at Caudebec-en-Caux, in northern France, which handles landing gear for Airbus (A300-600R, A320 Family and A330) and Boeing (747-400 F/ER/ERF, 747-8, 777, 787 and MD-11), overhauled 350 legs last year. Two thirds of these were for widebodies, which require 2.5 times as many man-hours as narrowbody landing gears. This year, the forecast is a throughput of 420 legs, a 20% increase.

He says the A300-600R and MD-11 markets are pretty flat, although the company has long-term contracts with cargo operators that are keeping the aircraft in service. The MD-11 work may receive a boost with the closure of Hawker Pacific Aerospace (see below), as Revima will be the only MRO source. The 747 market, again mostly cargo aircraft, has stayed around longer than expected but will probably start to decline in the near future.

The largest volume of work comes from the 777-300ER, with the number of contracts probably making the company the largest MRO provider. However, the 787 is set for significant growth, not least because Revima is a member of the Boeing Landing Gear Program. It will replace the 747 and will eventually become the main product in place of the 777. Overhauls now are from the 787-8 but the first 787-9 overhauls will start appearing in the next two years.

Introduction of the 787 has required significant investment. The legs are chrome free, using High Velocity Oxygen Fuel (HVOF) spraying to provide a greener and tougher surface. As machines have become due for replacement, the new equipment must be able to deal with the harder surface. Last year, this included a brand new CNC grinding machine and lathe, while a large grinder is scheduled for delivery in 2024 and a large boring machine in 2025. He notes that the surface on legs coming back for overhaul has been in good condition so investing in HVOF spraying equipment is not a priority at the moment. Another environmental initiative under development is the replacement of cadmium plating with zinc nickel plating, in accordance with the EU REACH program.

Turning to the post-Covid challenges, he feels the company could have handled more than 350 legs last year but for supply chain issues, where components that had always been available were suddenly unavailable. As a result, the company has had to spend an increased amount of time chasing suppliers, developing and proposing workarounds, sourcing used serviceable material, developing repairs and requesting OEM engineering assistance for consideration of adjusted tolerances. In addition, while some 500 people work on landing gear and the company suffered relatively few personnel losses because of its rural location, there was still a training requirement for new hires.

To complement its landing gear MRO services, Revima’s Normandy Aerospares business (the Used Serviceable Material entity of the Group) devoted a portion of its Yainville facilities (7 miles away from the Caudebec site) to carry out landing gear overhaul, especially with mid-life solutions. The market demand for these services is high, but, by its nature, is opportunistic, which did not work well with more planned MRO flow at the main facility.

Rémy Maitam is president, Asia Pacific at the company’s satellite facility in Thailand, at Chonburi, 60 miles north of U-Tapao–Rayong–Pattaya International Airport. It specializes in Airbus A320 Family and Boeing 737NG landing gear, although an agreement signed with Liebherr-Aerospace in April 2023 will see it expand into Airbus A350 nose landing gear MRO in Asia-Pacific. Construction of the 120,000ft2 facility began in February 2019 and was completed in March 2020. In parallel, there was a significant staffing and training program, with local recruits being trained at Revima headquarters. Staff from France also relocated to Chonburi to oversee initial maintenance. Now, he says, the staff are almost entirely Thai, supplemented by specialists from Hong Kong, the Philippines and Singapore.

The $40 million facility is equipped with the latest machinery and tooling, fully connected for smart monitoring and maintenance processes. It is environmentally friendly, with wide use of green chemicals and no waste rejection for its plating facilities. It is also equipped with brand-new machining and test equipment, to high performance non-destructive equipment. Annual capacity is up to 600 legs.

Part 145 certification (Civil Aviation Authority of Thailand, EASA, FAA) was achieved in early 2021 but capabilities were limited to disassembly and assembly, parts repair being outsourced to France. By mid-2022, full capabilities were available after plating and machining shops were added, including five-axis milling and grinding machines, hydraulic test benches and NDT.

Since then, operations have been in full swing, with 140 legs overhauled last year and 240 forecast for this year. The company counts low-cost carriers amongst its more than 30 regional customers, such as Citilink in Indonesia, AirAsia and its affiliate airlines AirAsia Cambodia, Thai AirAsia, Indonesia AirAsia, and Philippines AirAsia. As a result, he expects high throughput until early-2026, followed by a drop until work picks up again in late 2026/7. To fill the gap, it needs what he calls ‘spot opportunities’, such as a smaller airline or a single aircraft, even a single leg, perhaps after a hard landing. Again, aircraft delivery patterns can help identify potential clients.

The company has noticed increased corrosion levels on some recent landing gear, which may be related to aircraft grounding during the pandemic. He explains that, after removing corrosion, oversized bushings have to be installed in the leg barrels to keep the required diameter.

The facility is environmentally friendly, with widespread use of green chemicals and no waste rejection for its plating facilities. It will follow the lead from France in the future and replace cadmium plating with zinc nickel plating and hard chrome by HVOF coatings.

LTLGS

For Lufthansa Technik’s Landing Gear Services division (LTLGS), part of the Aircraft Component Services business segment, a major change is coming. Work is carried out at three locations at present:

LTLGS UK in London, located near Heathrow airport: predominantly Boeing (737, 767 and 777, the last 747 and 757 gears having been overhauled last year. The exception is the Airbus A380, with Collins wing- and belly-mounted main gear (four legs in total). Nose gear MRO for the A380 is the exclusive preserve of the OEM, Safran.

LTLGS Hamburg: predominantly Airbus (A320 Family, A330 and A340). The A350 is missing as, assuming the same 12-year replacement cycle as the A380, and with entry into service in early 2015, there is no need to build up landing gear overhaul capabilities just yet.

Hawker Pacific Aerospace in Sun Valley, California, which specialized in Airbus A300, A320, Embraer E-Jets and McDonnell Douglas DC-10/MD-11.

Unfortunately, Hawker Pacific Aerospace, which was acquired in 2002, has suffered years of financial difficulties, primarily because of work on legacy aircraft and a small market share. It has now been decided to wind down and eventually close it by 2025. The facility will stop taking in new gears in March at the latest, with closure in the summer months of 2024 after work is completed. The final closure is planned for some time in 2025. The aim is to fulfil all customer orders until the end of operations and to reach agreements on existing contracts. Lufthansa Technik’s management made sure that the company has established a comprehensive separation and incentive program for its employees, with the possibility to transfer to any other Lufthansa Group company.

Christian Rodarius, managing director/CEO of LTLGS UK points out that despite the difficult decision to wind down the operation of Hawker Pacific in the U.S., , the rest of the Lufthansa Technik Landing Gear network in London and Hamburg is flourishing. With work coming in from almost all the Lufthansa Group airlines (Lufthansa, Austrian Airlines, Eurowings and SWISS) as well as a worldwide customer base of passenger and cargo airlines, leasing companies and MROs, the workload is high, with around 350 legs processed last year in each of both locations. In addition, LTLGS also offers AOG support, an exchange pool for gear legs and a spares pool.

He says Covid caused some problems but a good throughput was maintained. This was helped by the size of Lufthansa Technik and its market power; even with supply chain problems, having a centralized purchasing process for the whole group is a huge advantage.

The Heathrow facility was previously owned by British Airways, dating back to Concorde days, although it has been extensively redesigned and upgraded since then, using Lean principles to form a U-shaped line inside the building, from goods inward to dispatch. Jad Kaakani, head of product line landing gear at LTLGS UK, explains that gears are cleaned, stripped and disassembled before inspection. Initially, they are placed on black trolleys, switching to yellow for inspection and purple for the rest of the process. Once the workscope has been established, piece parts are sent to various sections for repair and overhaul. They are accompanied by paperwork at every stage to avoid any omissions and to build a database that can help predict what will be required on a leg of a similar age.

The machine shop, with CNC grinders, can manage a range of tasks, including the manufacture of bushes and thread repair. The plating shop uses cadmium, chrome, Alucrom and nickel. Although the Heathrow facility is no longer in the EU, it still follows REACH program requirements. After final paint and inspection, the components come back together in an assembly area that has eight widebody and four narrowbody bays.

Kaakani says it is important to keep the facility constantly loaded and, indeed, the empty goods inward area at the start of the walkround had received a 777 main landing gear by the tour’s end.