COVID 19: Driving Digital and Remote Maintenance? Charlotte Daniels

by Charlotte Daniels | Nov 10, 2020 | MRO IT

In March, the FAA released a policy recognizing the value of remote technology for manufacturing and certification processes. Remote technology can streamline costs and optimize resources in the right environment. But what exists today, and how can it combine with digital solutions to assist operators and MROs going forward?

Aviation is a cautious industry, not known for embracing new, ‘disruptive’ technologies without years of use cases and regulatory support.

The paperless revolution is one example. The shift from paper documents, to dynamic systems and mobile devices is still painfully underway. A mix of paper and PDF documents is still common.

One theme that connects disruptive technologies is digitization. “All information needs to be in digital form, which remains a sticking point,” says Mark Roboff, general manager for digital transformation, Aerospace & Defence at DXC Technology. “The industry has seen many initiatives to speed this up, change has been sluggish over the last decade, and today there are still countless examples of paper-based processes in MRO.”

One wonders long it will take the industry to embrace remote technologies. Today, remote maintenance technology comes in many forms – some fully developed, others in infancy. The argument for remote tech is much the same as other disrupters; it promises more efficient, reliable operations and significant savings. It ranges from virtual platforms such as Microsoft TEAMS, to drones and augmented reality (AR) systems.

Yet along came Covid; the pandemic has turned aviation upside down, but aircraft still required maintenance. “Crisis periods are often an accelerator for new technologies,” begins Helene Druet, head of Marketing at Donecle. “The years to come will be challenging. Operators have to find savings, meaning a need to improve maintenance efficiencies.”

The onus is on managing labor effectively, reducing man-hours, and limiting mechanics’ movement. “Remote technologies are perfectly aligned with the new normal,” says Dinakara Nagalla, chief executive officer of EmpowerMX. “While it is still impossible to talk about complete remote maintenance – we still need hands touching the airplane – the new functions facilitate doing a lot of tasks remotely.”

Regulatory View

The FAA’s policy PS AIR-21-1901 was the result of three years of work to create remote technology policy best practices. The regulator expedited implementation during the pandemic, to provide additional tools for FAA inspectors and engineers to conduct safety investigations and perform regulatory oversights.

While PS AIR-21-1901 is not applicable to airlines and MROs (only to FAA Aircraft Certification engineers, and manufacturing aviation safety inspectors), the regulator recognizes the value of remote technologies. Its Flight Standards Service has used a range of virtual tools such as Zoom, text and Skype during the pandemic. “In some ways, COVID-19 has enhanced flexibility in real-time communication between the FAA and the industry it regulates,” says its representative. “The FAA is realizing benefit in renewal of operating certificates for repair stations operating under 14 CFR Part 145 rules, particularly those overseas, and activities associated with General Visual Inspections.”

“We are able to review manuals, interview key personnel, audit records and perform myriad other tasks remotely,” they add. “Our inspectors are using remote technology to accomplish certification tasks of both organizations and individuals more so than in conducting surveillance of certificated entities. We will undoubtedly expand our use of remote technology as a supplement to methods.”

Remote Maintenance

“Remote maintenance is a broad term,” says Roboff. “To me, the heart of the technology is augmented reality (AR) or virtual reality (VR) devices that are applicable for the MRO environment. These devices can provide solutions for remote expertise including training and non-routine (NR) assistance,” he explains. In addition, technologies that enable automation (such as robots performing aircraft inspections for a mechanic) are other popular interpretations of remote maintenance technology.

“Today, automation has a lead over AR/VR in the hangar,” adds Roboff. “There have been some successful, public use cases for using drones to inspect fuselages for cracks. The value proposition for this technology was not in removing workforce but in speeding up inspection time. It’s important to consider that any disruptive tech that has been bought to MRO’s primary purpose is to drive a speed up of turnaround time (TAT) and reduce AOG.” The onus is on robotics or systems assisting, not replacing, humans in performing a task.

Why is it needed now more than ever? “When we emerge from Covid the industry will be smaller,” Roboff continues. “On top of this, we’re looking at an evolution of a younger workforce and mechanics near retirement after being in the industry 20-30 years. We’ll be needing to train a younger, replacement workforce at scale and will need to do this effectively.” As will be explored, AR/VR can address the labour transformation of a shrinking industry.

Several areas in MRO directly benefit from remote maintenance technology. “The first two coming to mind are inspections and the interaction between the MRO and an airline’s technical representatives,” says Nagalla. In response to the pandemic, EmpowerMX launched its Touchfree Electronic Taskcard, which combines remote technologies with a mobile taskcard to allow direct streaming of calls and video technology onto an e-taskcard. “The range of activities, which can now be inspected from a distance, has increased thanks to remote technologies. Our customers, most notably JORAMCO in Amman, Jordan, have expanded remote inspections.

“In terms of customer technical representatives, right now there aren’t any activities they cannot perform remotely using our software. A typical rep can receive notifications on his or her mobile device whenever there are time and materials estimates requiring approval by the airline operator, adds Nagalla. “They can access a mobile app and browse through the technical details of the requests. The details may include pictures, videos, audio files and other documents substantiating the level of work requested.” The technical representative can also use the built-in video conferencing functionality from EmpowerMX to ask the MRO experts for additional clarifications. All these exchanges and transactions can be saved as part of the permanent task card record in the MRO system.”

Nagalla anticipates that COVID will lead to an increase in line operations being outsourced to independent providers. “For MROs taking over these activities, but most importantly for the airlines contracting their services, it will be beneficial to configure the operator’s maintenance information system to accept direct updates from the MRO system,” he says. This will allow remote overview for the airline. Digitization is once again a factor, however. “In some cases, this is complicated due to the legacy roots of the solutions used by the airline. We developed a universal interface connector (UIC) to provide this connectivity. Our UIC goes beyond connecting airlines and MROs using the same IT solution, and covers companies with disparate IT portfolios.”

Chris Clements, sales representative at Swiss AS agrees that managing contracted maintenance is one of the main challenges during the pandemic. “Having a Customer Rep on site to monitor aircraft is now problematic,” he says. “Managing these situations is where MRO software such as AMOS can bring benefits, allowing airlines to remotely assess progress.” Not only does AMOS enable paperless processes, but its standard interfaces allow work packages to be imported and updates exported at regular intervals via AMOSmobile/EXEC. “This allows the customer to have their own work package updated in their MRO software solution to continuously monitor progress. Combined with electronic signatures, and the ability to send findings to the appropriate person via AMOS, face-to-face contact is reduced.”

“The problem is the quality of data varies,” continues Clements. “The MRO needs to ensure the estimates provided by the airline on the work package – such as access time and man-hours – aligns with theirs. The MRO often needs their own means of tracking progress and makes finding a solution more complex.” Today, Clements explains it’s still common for MROs to print work packages onto paper, and add a barcode on each task to bill and track accordingly. “Hybrid efforts are also underway,” he adds. “We have customers that receive scanned PDFs of task cards and overlay sign-off blocks from their tablet.”

Aircraft structural repair and continuous monitoring are further areas of maintenance that benefit from remote technologies, and can be achieved through the use of drone and video-link capabilities. “Drones are one of the most effective methods of remote maintenance,” says Shiyas Asaf Ali, senior aircraft engineer. “This would actually help reduce maintenance time and provide more accurate interpretation of fuselage defects. Aircraft with poor tolerance of lightning strikes can use drones to identify and document defects on the fuselage.”

Drone Technology

Founded in 2015, Donecle is one of the leading providers of automated aircraft visual inspections. The manufacturer of a fully automated drone specially designed for hangar environments, Donecle has signed with several customers including AFI KLM E&M, AAR, LATAM and Austrian. “The drones are being used for use cases from line and base maintenance up to paint wear evaluation or lightning strike mapping,” commences Helene Druet, head of Marketing at Donecle.

The drone does not need a GPS signal to navigate or operate. As such, it does not fall foul of the lack of GPS coverage that can hinder maintenance in remote areas. Instead, its position and tracking capability uses laser technology and pre-planned flight paths, while the system has its own encrypted WIFI network. “Creating our own drone allowed us to embed safety features such as obstacle detection and systems redundancy,” explains Druet. “Our sensor is mounted on a rotating gimbal to allow picture acquisition of the complete airframe, including upper surfaces, belly, under wings and so on.” These drones don’t just capture a standard image, however – it feeds through to an image analysis software to easily detect and locate damages on the aircraft surface. “Our solution also comes with a cloud platform to store data and reports,” she adds.

The drones utilized by Donecle allow both a ‘hands off’ approach to maintenance for its user, and reduces the need for more than one mechanic to undertake certain inspections.

Beside the ability to inspect the aircraft from the ground, is the complete view of the aircraft condition and remote access to data. “This has been the driving benefit Donecle has provided in recent months,” continues Druet. “For people working from home or not able to come on site because of travel bans, drones allows efficient collaboration between MROs and 3rd parties. Engineers can perform the inspection remotely based on the data captured by the drone at the hangar and then share inspection results with colleagues.”

Remote Processes

For organizations with some digital capability, and who utilize M&E and ERP systems in conjunction with mobile applications and devices, a degree of remote collaboration can already be achieved. Utilizing popular methods of communication including Facetime and Whatsapp, available via mobile devices MROs can share video, audio and electronic information. These means of communication have now been part of day-to-day life for many years, which increases the confidence of companies to implement them.

“The ability to add video data to an e-task card for a fault, and establishing collaborative platforms are the least disruptive forms of remote maintenance, because they work with existing mobile technology,” says Dan Dutton, vice president R&D, Aerospace & Defence at IFS. It’s easy to see how a drone could feature in this process; feeding video into electronic task cards for departments to discuss remotely using a collaborative platform.

“We continue to work with vendors to offer customers ways of plugging remote inspection footage into their electronic task cards, facilitating damage analysis and, if required based on system configurations, save the video feeds as parts of the permanent compliance record,” says Nagalla. “In future we will see more video and audio conferencing as a way of promoting remote collaboration. When it comes to dealing with drone video footage the maintenance system needs to be able to receive the inspection feed via webservice and, upon user selection, create a finding or unscheduled task cards so it can be linked it to the high-resolution images and video, worked and corrected.”

IFS Remote Assistance

In response to the challenges faced by businesses during a pandemic, IFS launched ‘IFS Remote Assistance’ – a remote collaboration platform designed for maintenance teams to interact remotely. The solution uses augmented reality to overlay information on top of a live video feed to allow experts off-site to virtually guide on-site technicians through a repair process or troubleshooting activity. “Remote Assistance can be offered to any customer as a standalone option,” explains Dutton. Because it’s a cloud-based application, Remote Assistance is easy to deploy for new customers and requires no local infrastructure.

By merging two real-time video streams, mechanics and technical experts can share images and information in a merged reality environment. “Because of the format, using a platform such as Remote Assistance is not a culture shock to users, and therefore is directly valuable and easy to implement,” adds Dutton.

Maintenance in a Pandemic

Maintenance has remained essential, yet complex due to travel bans, social distancing, and shifting MRO requirements as aircraft are grounded. Heavy checks intervals are based on an assumed number of flight hours (FH) and flight cycles (FC). If an aircraft stops flying and goes into storage, this affects when some checks will become due.

IFS released a ‘Clock Stoppage’ extension to its Maintenix maintenance system. This allows airlines to meet business requirements of a storage program as directed by OEMs. “The clock stoppage solution applies deadline extensions to calendar tasks,” explains Dutton of IFS. “The intent of the clock stoppage caused by COVID-19 is to allow postponement of some maintenance program tasks as directed by the aircraft OEM while aircraft are under a storage/parked aircraft program.” The advantage to planning and MRO is a highly streamlined approach to adjust these maintenance parameters which allows customers to quickly plan for the reinduction and return to service of their parked aircraft once they are ready.

Ali explains that the need to park aircraft during Covid has raised significant maintenance challenges. “Primary challenges are preservation tasks which is basically covering the various access doors, inlets and engine inlets exhausts, sense lines etc,” he adds. “Since this is not a regular task being performed in an operational environment, it has many challenges of its own. Time taken to preserve/ de-preserve each airplane varies and eventually return them back to service means a series of tests which needs to be passed.” While in his experience airlines have not made significant changes to digital maintenance procedures since Covid, Ali says challenges created by the pandemic will accelerate digitalization in aviation.

Remote Collaboration is Vital During Covid

Digital solutions and processes allow airlines and MROs to take advantage of rapid advances in technology. They also provide them with MRO M&E software that is scalable, future-proof and provides the support needed to expand or provide different MRO services. The classic case-in-point is how forward-looking organizations have withstood the changes brought on by Covid pandemic, such as meeting social distancing and remote working conditions. By virtue of having mobile and paperless operations supported by digital technologies, organizations have been able to minimize the effects of disruptions brought on by Covid. Digitization will bring incremental benefits such as optimizing cost and the elimination of paper and non-productive tasks. However, remote collaboration is changing the way technicians work and paving the way for the future aircraft maintenance.

Aircraft maintenance is a collaborative task where technicians, engineers, tech services, stores and other departments work together to ensure safety of every flight. The technology and platforms they usually choose to collaborate with would be a phone call, email or any of the social media messaging apps. This makes it difficult for everybody to be on the same platform during work hours, as well as increases the burden to access multiple types of hardware while working on the aircraft.

Ramco says their Remote Collaboration tool which is integrated within their Mechanic Anywhere mobile app can solve this challenge. Within the app all departments in a company using Ramco’s M&E MRO Solution can interact with each other electronically using instant messages, screen share and even voice or video calls. “The Remote Collaboration tool can help a technician seek assistance from colleagues or supervisors and the technical services to review the latest revisions in an MPD or Task Card with the maintenance team,” says Ramco.

Through Ramco’s Remote Collaboration tool, the entire company is connected to each other on a single aviation ERP platform sharing ideas, discussing topics and completing work faster, thus improving overall operational efficiency.

Optimizing Digital Systems

Covid has provided a landscape that proves the benefits of digital and remote processes. Unsurprisingly, operators and MROs aren’t looking to invest or adopt new procedures right now. “They’re in survival mode,” says Ian Kent, product manager at Rusada. Rusada’s ‘Envision’, a web-based suite of modules, offers digital solutions for key areas of aircraft operations and maintenance.

“For most operators and MRO providers, making these investments can follow once they’ve weathered the storm,” Kent continues. However, Rusada has seen some clients utilize the downtime of grounded fleets to completely reassess their processes, with tangible, positive outcomes. Manta Air, a domestic tourist operator based in the Maldives, saw operations decimated due to the pandemic. With its ATR fleet grounded and staff unable to perform their regular duties, Manta seized the opportunity to evaluate how to maximize the use of Envision.

By gathering eight teams, each comprising eight people from different departments, Manta tasked each group to list the software each department uses. It then tasked the teams to investigate all the functions each department performed. “Every process was questioned and assessed,” explains Kent. “When it came to the engineering department, Manta realized they were using less than half of the capabilities Envision provides. This was due to some cultural resistance to change, as Envision was relatively new software to them.”

Manta saw the full potential their M&E system could provide and so contacted Rusada to arrange additional software training sessions (all, of course, remote). “Two months on, and their utilization of Envision was 87%,” adds Kent. “Manta pushed through the resistance to change and is now seeing the benefits, including greater efficiencies and leaner operations.”

Mixed Reality: A Virtual Mechanic

The ‘Hands-off’ side to remote maintenance could mean robots and drones performing inspections in time. However, it can also refer to mechanics physically handling less paper while in the hangar. Not having to rifle through documents while carrying out tasks or troubleshooting is a further means to increase labour efficiency, and a step away from paper processes. AR/VR is key to achieving this.

“We are seeing Virtual Reality already being used in areas like technical training and simulation of aircraft interior designs,” says Nagalla. “Augmented Reality, on the other hand, could be useful in maintenance environments where the proper hardware could be used to present technicians with actionable information and provide a portal for remote collaboration.”

Training will likely become an area that will hugely benefit from AR. According to Druet of Donecle, industry analysis anticipates the rising challenge of workforce shortage in the MRO World. “We need to motivate new generations to embrace careers in MRO, and implementing new technologies at work is one way to differentiate and attract people,” she explains.

Roboff of DXC outlines the use case for a ‘virtual mechanic’ built using augmented reality. “We’re talking a voice on a mechanics shoulder, and the ability to streamline manpower at a time it’s most needed,” he says. “This is where AR and VR comes into its own.

“Today, a mechanic carries out tasks while referring to maintenance manuals, essentially ‘reading and doing,” Roboff continues. While some might use an iPad to access the manuals, many still use printouts or books.

Adding a VR device to the process changes the dynamic. ““A component supplier recently undertook a study that showed mechanics spend 40-60% of their time looking at a paper manual to follow instructions,” explains Roboff. “A VR device such as the Hololens can eliminate some of that work by replacing the manual. However, overlaying instruction text via the Hololens is static, and the mechanic still has to physically read the text it provides.”

Roboff envisages a cognitive agent (CA) integrated with a VR device, which can convert text into speech creating a virtual technician for mechanics to utilize. “This becomes a conversation, rather than a one-way interaction between man and device,” he adds. This is particularly relevant for non-routine findings and faults in line maintenance, where isolating faults requires trial and error to diagnose. “The technician can respond back to call up the right next step,” Roboff explains.

Utilizing a VR device such as the Hololens means video can be captured. But before a CA is added the use case is limited. “AR/VR will really and only take off when it’s paired with the agent,” says Roboff. “The technology exists, but unifying data standards needs to happen to accelerate the process.” This will make the process of interfacing manuals another documentation from OEMs and airlines simpler. “To build an AR system, we have to convert PDF manuals into a format that can be digested by the CA, which takes time.” Moreover, AR/VR systems and devices remain relatively immature, and not designed for aviation operations. Roboff highlights in the case of the Hololens, the apparatus does not work well in large open spaces and natural light. The latest model, Hololens 2 offers improvement, but the hardware still needs maturity.

Dutton thinks the future of AR looks bright for MROs. “AR has radically improved over the past couple of years,” he says. “Increasing regulatory support now means airlines are open to working through the early challenges of adoption.”

The Future

Druet of Donecle thinks Covid has introduced new ways for remote systems to be useful. “We’ve seen the development of new use cases such as end of lease and all aircraft transition topics when lessor inspectors can’t physically go to the inspection,” she summarizes. “We expect more solutions working towards remote inspections and remote collaboration tools, therefore accelerating the digitalization of maintenance activities.”

Roboff’s hope is that now, with parked planes and less demand on resources to operate full services, operators might find now is the time to set aside investment and resources to dust off the filing cabinets and start to digitize. “Survivors will need to be agile,” he summarizes.

Predictive Maintenance Analytics: Smarter, Safer & More Efficient Operations By Charlotte Daniels

by Charlotte Daniels | Mar 27, 2020 | MRO IT

Predictive maintenance has progressed from industry buzzword into a goal for many operators. Today, several airlines and MROs are demonstrating how to use data to increase fleet reliability. But how are they able to fully benefit from the vast wealth of information available, and mine it effectively without incurring unmanageable costs?

Tata comes in many forms and from various sources in an airline – the vast amount available today created the term ‘big data’. Unless robust digital solutions are installed that can aggregate, distribute and analyse information, data is useless. Complex algorithms are required for this analysis, specifically machine-learning algorithms to handle aircraft and engine sensor information.

According to an Oliver Wyman MRO Survey, the global fleet of commercial aircraft could generate 98 million terabytes of data per year by 2026, due to big data. Aircraft data comes from sources including the flight data recorder (FDR), engine health monitoring (EHM) and airframe health monitoring (AHM); each receiving and transmitting thousands of parameters from in-built sensors, often down to component level. The amount of data has implications for transmission costs and for an airline’s connectivity and storage capabilities. That is, for the data to perform proactively, it needs to feed data regularly into maintenance (M&E) and operational systems to create a current picture. Having the infrastructure for this can feel cost-prohibitive for carriers.

Engine and airframe original equipment manufacturers (OEMs) were initially at the forefront of these digital solutions; as aircraft become more sophisticated, the intellectual property (IP) that governed them meant that OEMs were ideally positioned to generate software that could manage data effectively. However, airlines with multiple fleet types still sought solutions that could ingest different data standards and forms. To maximise the ability of big data in the industry, it can’t be kept in-house. “Today, OEMs, airlines and maintenance, repair & overhaul (MRO) operators are showing interest not just in gathering data, but sharing it for a number of different uses—predictive maintenance or health monitoring systems being key applications,” says James Elliott, Principal Business Architect, Aerospace & Defence at IFS.

Predictive maintenance is explored here. By utilising solutions that can interpret aircraft data, maintenance control centres can build a day-to-day picture of individual aircraft (and fleet-wide) performance. Overlaying this with historical information means one can forecast – using advanced analytics – when a part will fault. Moreover, this performance data will contribute to the historical data – meaning that predictive models generated become ever more accurate. By predicting fault behaviour, operators can schedule maintenance ahead of the fault being flagged in operation.

As Aerospace Technology Week approaches, ATR is reviewing the industry stance on predictive maintenance analytics – that is, how are airlines best utilising maintenance and operational data to maximise time-on-wing (TOW). “Ideally, predictive solutions shall reduce the overall cost of operation, reduce interruptions and increase the reliability of the fleet,” agrees Frank Martens, Head of Customer Development Digital Products at Lufthansa Technik (LHT). “There is no generic number available, but some predictive solutions reduce the number of unscheduled removals by 80%, and just one predictive solution can save an airline more than a million Euros per year, but this strongly depends on specific operational patterns.”

Before predictive maintenance can reach maximum potential in the industry there remain challenges pertaining to data ownership, connectivity and regulatory support.

Data Origins and Access

In addition to FDR, AHM and EHM data, predictive maintenance can utilise information from other sources to present a robust picture of aircraft and engine performance.

Honeywell’s digital platform – Honeywell Forge – supports its Connected Maintenance application. Connected Maintenance analyses aircraft data in order to generate trends, maintenance alerts and proximity warnings for failures and faults. Honeywell Forge then allows customers to assimilate and distribute data effectively, which are key for predictive maintenance. “There are a variety of data sources used for predictive maintenance, namely quick access recorder (QAR) Data (or a subset thereof), ACMS Fault Messages, ACMS Performance Reports, and Maintenance Tech Logs,” describes Josh Melin, product line director for Honeywell Forge Connected Maintenance at Honeywell. “The richest data set is direct sensor data from the 717 bus or 429 buses which can be pulled from the QAR, or tapped directly from the bus using wireless enablers. These can be installed on the aircraft.”

While wireless enablers can simplify data flow for airlines, Melin adds that data can be extracted in other ways for the operator, with no need for aircraft modification or retrofits. “We do find, however, that if data is not collected regularly, the value of predictive maintenance solutions is lower, because predictive maintenance relies on regular data feeds to predict failures,” continues Melin. “Furthermore, it is important that the airlines owns the data it generates, and can decide which elements to share and withhold. So Honeywell actually does not need a full set of QAR data to create a predictive solution, in fact, we only need a subset of data labels from the 717 bus which we can provide as a list to the airline.” Melin adds that Honeywell can offer wireless enablers to the airline which can tap the 717 bus and pull only the exact parameters needed to provide the service the airline requests.

If an airline has issues pertaining to cost, data ownership or distribution, Melin explains that Honeywell does not need to collect all aircraft data in order to provide a predictive solution. “Honeywell Forge has airlines providing everything from ACMS Performance Reports, QAR data, to Maintenance Tech Logs in order to formulate their solution. While all the data sets listed are ideal, it’s possible to get started with just a subset of data, such as ACMS data and then as ROI is established the data set can be expanded,” he adds. The solution started as a tool to analyze data coming from thousands of Honeywell APUs. In 30 years, just one model of Honeywell APU has amassed over 100 million hours of service data; an ideal starting point for predictive analytics involving the complex systems which make up the APU.

Saravanan Rajarajan (Saran), Associate Director for Aviation Practice at Ramco Systems explains that maintenance-related data on the Components / Aircraft recorded in their MRO platforms provide another data stream for predictive maintenance. “Non-routines, removals / NFF / minimum equipment list (MEL) occurrences and Operator Maintenance programs all enhance predictive data analytics,” he says. “Analysing both the operational data from the sensors and the MRO data is key for high accuracy.”

Due to the data now available from connected aircraft, Sander de Bree of Exsyn Aviation Solutions adds that operators can now go further than traditional maintenance and health data, to boost predictive and analytical capabilities. “Non-aircraft related data such as weather information and airport data are important data-sources to be used in predictive maintenance algorithms,” he says. “These can be used to detect the impact of operational conditions (such as dry or humid operations) on component health. Additionally maintenance data from MRO’s needs to be used to report back any failure data to an operator’s prediction models.”

Data platforms and advanced analytical capabilities aside, there is one digital tool that a growing number of operators use today: the electronic techlog (ETL). It was the implementation of this device for recording faults that gave rise to the potential for predictive maintenance to flourish. It is also the primary interface between operational and maintenance data; an area where data can become disconnected.

“Data for predictive maintenance is critical, as there are so many areas in which it can be exploited—if it can be collected,” explains Elliott. “Think about a paper technical logbook on the plane, which is only accessible by a single person at a time. Handwritten entries cannot be used in analytics, and cannot be mined for information.

“An electronic, connected logbook can be used by multiple people at the same time,” continues Elliott. “A mechanic can see what faults are on the aircraft, and arrange for proper parts and tools for arrival at the aircraft. And, of course, that digital data can be aggregated and mined. The Internet of Things (IoT) will also help, with sensors being used to measure and collect data.

Digital twins are one industry development linked inherently to predictive maintenance, and applications of the technology are becoming more prevalent. For example GE has helped develop a digital twin for an aircraft’s landing gear. “In this last scenario, sensors placed on typical landing gear failure points, such as hydraulic pressure and brake temperature, provide real-time data to help predict early malfunctions or diagnose the remaining lifecycle of the landing gear,” adds Elliott.

Preventative vs. Predictive Maintenance

There are two core approaches to data-based maintenance, each geared towards different connected capabilities of aircraft or component. For instance, an A320 Classic aircraft will not transmit the same level of operational data as the A320neo; therefore maintenance strategies are different.

Preventative maintenance relies more on ‘trend monitoring’; trying to prevent a fault from being flagged by a line maintenance team by removing a component in the next scheduled maintenance event. The onus is less on the data being transmitted ‘that minute’, or the condition of a specific serial number, but rather taking an intelligent look at historical patterns across a fleet with that part installed, and determining based on age and hours or cycles when that part should be removed for inspection. But is preventative maintenance less dynamic or effective than predictive maintenance? “Preventative maintenance is an age-based maintenance philosophy, not taking into account actual condition of systems & components,” explains Sander de Bree, founder of EXSYN Aviation Solutions. “Predictive maintenance aims to use the actual calculated condition of components (based on operational usage) to serve as triggers for maintenance requirements.”

“Effectiveness of the predictive maintenance (over preventative) lies in its ability to leverage the historical data alongside live operational data,” explains Saran. “This is purely aided by the latest developments on processing the high volume of dynamic data feeds and analysing with sophisticated statistical tools. Because preventive maintenance relies only on historical data it is less effective.” Moreover, the age-based approach often leads to parts being removed ahead of time; meaning ‘wasted’ time remaining on the part if not re-installed.

There are instances where preventative maintenance is more appropriate for operators. “It is a good option in the absence of insights into the actual condition of a component/system,” describes Melin. “But as those insights become available, moving from preventative to predictive can ensure that maintenance actions be prescribed to exactly what maintenance action is required to remedy the current issues and at the right time.”

Data Hurdles in Maintenance

One of the main hurdles preventing operators from investing fully in predictive maintenance initiatives is the data itself – the completeness of it, and the ability to synch data from different sources, departments and formats.

Melin of Honeywell states two primary hurdles that preventing airlines realising predictive maintenance potential. “Some Airlines have a wait-and-see approach to data sharing. This is understandable but unless it’s shared, it is difficult for a software provider to demonstrate potential,” he explains. “Moreover, airlines’ traditional decision-making processes are tough for the software, applications and platforms that can harness and interpret data.”

“Airlines should be in full control of their operational data and be able to share it with their partners like MROs for example,” elaborates Martens. “We doubt that the approach of certain OEMs to restrict operational data access and control will prevail, since all airlines have a strategic interest to control their data.”

“Feedback from component shops on the actual health of components once removed from the aircraft based on prediction models is another hurdle,” adds de Bree. “This information is not readily available to airlines either because they are in a parts pool programme, or have components contracts based on time on wing (power by the hour). For the latter, there is an economical incentive to classify parts removed based on predictions as no-fault-found (NFF). After all, the part did not fail on wing ‘yet’.

“Also, many airlines are looking into predictive maintenance; some with OEM’s, some independently. Currently it seems a race for the best possible algorithm and platform, meaning each initiative is siloed. To make predictive maintenance work we need OEMs & local CAA’s to approve changes to the MPD, airlines to make available operational data, MRO’s to make available maintenance records and solution providers to provide algorithms and calculations,” says de Bree.

Data Platforms & Infrastructure

One way to connect data from different applications and departments is via a data platform; a repository that can exchange information between applications and systems – for instance between an ETL and an operator’s M&E system. “The most data-driven often work with a provider that can cover their entire fleet,” says Melin, “which for many airlines consists of multiple aircraft types from multiple aircraft OEMs.”

“The responsibility for the maintenance of an airline is of the operator and its CAMO and not the OEM’s expertise,” explains Martens. “More airlines realise the potential of digital solutions and the requirement to adapt these solutions to the specific needs of their fleet and operations. Open digital platforms like AVIATAR enable operators to provide digital interfaces to MRO’s and other players in the market, who help them in maintaining their fleet.”

Elliott explains that airlines are starting to work on their own data platforms to get in on the benefits of sharing engineering data. These platforms were initially pioneered by airframe and engine original equipment manufacturer (OEMs) in order to support OEM-developed applications that are often chosen when operators order new aircraft types. Furthermore, OEM platforms benefit from having access to global customer data, thereby bolstering their analytical data provisions. “Airbus launched its cloud-based data platform, Skywise, in 2017 which collects data such as work orders, spares consumption and flight schedules from multiple sources across the industry for MRO operators to perform predictive and preventative maintenance. Early adopters included easyJet, Air Asia, Emirates and Delta Airlines, all of which are using the platform for predictive maintenance,” says Elliott.

Not all data is so readily available. “Sensor data from aircraft is still “locked-up” with the OEM’s as it mostly uses OEM IP in order to be decoded,” highlights de Bree. “You do see independent flight data acquisition avionics becoming available to work around this issue.”

According to Ramco, an M&E MRO system provides the foundational block to support predictive maintenance capabilities. “With the recent advancement on data processing power and ability to store TB of data , the key challenge is agility to connect to the external eco systems and leverage with inhouse data for prediction,” adds Saran. “API based protocol is essential for the organization to achieve software collaboration and encourage data sharing.”

“The number of airlines using the latest big data solutions is limited but growing fast,” adds Martens. “Many airlines are looking at the solutions, but the offerings of real predictive maintenance are limited. Many offerings just provide digital results without direct connection to maintenance actions. Connecting a data platform such as AVIATAR with different M&E System vendors like AMOS or TRAX and other airline IT providers such as Netline help to create the necessary solution.”

Data Transmission

Much of the data required for predictive maintenance suggests a high level of data transmission; but to what extent does this need to be performed in-flight, which incurs a great cost? “Data synchronized in flight is mainly linked to EHM/AHM parameters or ACARS data and contain fault messages once a situation has already occurred,” explains de Bree. For instance, while LHT’s AVIATAR ingests data from multiple data sources in-flight and on the ground; the extent of this is defined by the operator. Engines and other components can send data via aircraft interfaces. “In many cases data such as fault messages is sent via ACARS in flight and Wifi/GSM on the ground, but this is up to the airline to define it, based on requirements,” says Martens. “For engineers it can be very helpful to receive these while the aircraft is inflight, since manpower, tools and spare parts can be ordered ahead of landing. This helps operators to save costs by avoiding AOGs (aircraft-on-ground).”

In general, airlines transmit the bulk of their data once on the ground, saving cost. “Honeywell Forge Connected Maintenance has been able to predict component failures days and weeks in advance,” says Melin. “The process of detecting an impending failure and alerting the relevant maintenance engineers can be automated. Typically, the process of then deciding when to complete that maintenance action and submitting the work order is still manual so that the airline can remain in control of that final decision.” Airlines can reduce operational disruptions with the current generation of systems, transmitting data on the ground. Honeywell believes that in future there will be a shift towards transmission of a subset of key data during flights, utlilizing existing satcom connectivity, in order predict a wider set of ATA chapters with high accuracy.

The ETL can provide the means to notify of faults inflight. “An effective ETL allows pilots to communicate with the whole team involved in flying an aircraft on the day of operations—spanning mechanics, maintenance control centres, engineers and more,” continues Elliott. “Once a pilot is flying, if they encounter any problems, they can log the fault in the electronic technical logbook app. On aircraft with in-flight internet connectivity the maintenance organization will receive a push notification in real time outlining the fault and start preparing work orders and parts, so they are ready to address it the moment the aircraft lands. From a more preventative perspective, on aircraft without in-flight connectivity, an electronic technical logbook can push updates to the maintenance department when the aircraft lands.”

IFS’s customer, China Airlines, has been utilising IFS Maintenix to optimize data sharing of real-time management of line and heavy maintenance events, as well as data capture at the point of maintenance across the airline and its subsidiaries. This included expanding third-party MRO services for the airline’s customers. “In addition to reducing operating costs by $3.5 million, IFS Maintenix has helped China Airlines significantly decrease its aircraft layover due to more efficient scheduled and unscheduled line maintenance,” adds Elliott. “This means that its aircraft spend more time in the air and less time in the hangar.”

“While real-time data transmission in-air is a benefit for EHM/AHM fault messages, for predictive maintenance trend calculations an offline datafeed is sufficient,” agrees de Bree. “In terms of wider infrastructure, server capacity is going to be critical to ensure timely processing of data and visualizing outcomes. As an airline you don’t want to wait 4 hours for a calculation to finish prior to giving indications on component condition.”

Unnecessary Part Removal

Removing parts if a fault arises is the traditional business model of the industry, and reactive rather than proactive.

An issue of predictive maintenance lies in the clinical and rigid nature of data if intelligent parameters aren’t built in; we run the risk of incorrect forecasts and erroneous ‘fault’ messages. For instance, if an operator forecasts that a component will fail within 200 hours, based on historical behaviour, it might schedule removal to prevent failure in operation. However, upon removal the part tests no fault found (NFF), costing unnecessary time and money for the operator.

How do we prevent parts being taken off for testing, only to be NFF? And is there risk of oversensitive data, causing unnecessary time off wing for testing? “No algorithm can be 100% reliable,” says de Bree. “The key is feeding back MRO shop data of actual components removed based on prediction models. This is the only real evidence if a failure of that component was imminent. Feeding back such data will make models more reliable.”

“Parts pre-emptively removed need to undergo longer troubleshooting time due to non -availability of fault code or maintenance findings,” says Saran of Ramco. “High sensitivity on the Part removals and longer turnaround time (TAT) will also lead to increased investment in float for airlines. The sensitivity can only be reduced over the time by a continuous closed loop data flow on maintenance findings on the removed part back into the prediction algorithms. It is also imperative that parts are sent to shops with the data leading the predicted fault which reduces the troubleshooting and turnaround time.”

“Ultimately, condition-based removal avoids costly AOGs, improves the fleet’s reliability and ensures high rates of passenger satisfaction,” counters Martens. “If MRO providers don’t know the predictive reason of the removal, it may lead to NFF, but the operator will save on operational cost. An AOG at the wrong location can cost more than €100,000.

“There are several examples where predictors are used successfully. The parameter of these parts are continuously tracked and analyzed, resulting in a trigger/information when the fill level/temperature/pressure parameters start to shift without causing a real aircraft failure. This helps us to change or service these parts preventively to avoid AOGs. Very often the work order can be transferred automatically into the maintenance information system,” adds Martens.

According to IFS, Rolls-Royce has disclosed high expectations for the accuracy of its own predictive analytics strategy. The OEM targets a 100 percent success rate in terms of ensuring they never miss something they are looking for, at the same time as zero false predictions including NFFs.

Predictive Maintenance vs. MSG-3

What effect might predictive maintenance have on scheduled maintenance? For instance, will airlines that maximise its potential still follow an MSG-lead maintenance programme? Or will we see an evolution away from this and scheduled shop visits? “Going forward condition-based maintenance will be used more often, but requires close collaboration between the authorities, operators, MROs and OEMs,” says Martens. “Predictive maintenance should result in less unscheduled, high priority repairs and eventually, we can make many checks obsolete because we calculate figures and probabilities per system which previously were checked manually.”

“Ultimately this might become a new maintenance standard, however no airline today is allowed by CAA regulation to deviate by themselves from the (MSG-based) approved maintenance program and OEM MPD,” explains de Bree. “As long as these are still leading, predictive maintenance initiatives can only impact on-condition components of an aircraft.”

“In the next few years, predictive maintenance can eliminate airline determined soft time maintenance intervals in order to optimize costs and efficiencies, however, it is less likely that predictive maintenance would be a substitute for hard time service requirements,” says Melin at Honeywell. “Ultimately, the change in maintenance practices must be spearheaded by airlines maintenance teams.”

Rolls-Royce is pioneering the concept of an adaptive and evolving maintenance programme, that can effectively go a step further than MSG-3 logic. In 2019 IFS partnered with the OEM to support its data exchange program with airline customers operating the Trent Engine family.

“The IFS Maintenix Aviation Analytics capability enables the automated provision of field data, which ensures that Rolls-Royce receives timely and accurate information on its Trent 1000, Trent XWB and Trent 7000 engines,” explains Elliott. “IFS Maintenix then acts as a gateway to automatically push maintenance program changes from Rolls-Royce back to the airline operators. As a result, life-limited engine part maintenance deadlines can be updated based on actual operating conditions and life consumed by each engine in use.”

Artificial Intelligence (AI)

AI is increasingly referred in conjunction with predictive maintenance. “The use of AI revolves around algorithms being used for predictive calculations to be become more reliable over time by themselves,” explains de Bree. “It allows systems to detect possible failures to monitor purely based on data supplied without any relation between parameters and component failure being known,” explains de Bree.

“AI is a valuable tool for analytics, along with machine learning and neural networks,” says Melin of Honeywell. “AI can be used to determine the state of a system (how it operates in given conditions) and then detect anomalies through time series data which can then be used to predict remaining life and recommend mitigation strategies. AI is different from the historically human-based maintenance systems in that it enables integration of contextual data as well as behavioural parameters of assets.”

In addition while AI can be used in predicting the item removal through predictive maintenance, it is also expected that it can offer additional services to increase the intelligence of the predictive maintenance solution, Saran of Ramco explains. “For instance, AI might also assist an M&E systems in suggesting part replacement options and other parts which might also be needed in replacement, therefore streamlining maintenance downtime. The confluence of Predictive maintenance, AI and Big data drives maximum benefit.”

For large-fleet commercial operators and aviation MRO providers alike, AI is now an essential tool. “Recent examples of airlines such as Delta, and MROs such as Lufthansa Industry Solutions working on adopting AI and machine learning (ML) into their aircraft maintenance strategies highlight the transition organizations are already making towards digital and predictive-focused maintenance strategies,” continues Elliott. “The reduced maintenance technician and engineering labour hours spent analysing data makes intelligent maintenance strategies particularly desirable.”

Want to learn more? Several presentations will take a deeper dive into predictive maintenance at Aerospace Tech Week. See page 43 for the full Show Guide.