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IOT, Data Analytics Drive New Airplane Health Monitoring Strategies

New airplane health monitoring technology and strategies focus on acquiring necessary flight data and faults on an on-demand basis, knowing when systems and components will fail before they do. This is how today’s airlines are monitoring the health of their multi-million dollar assets.

Commercial airplane health monitoring is evolving rapidly both technologically and conceptually. Airlines and airplane original equipment manufacturers, engine makers, sensor suppliers and software companies are all working in an interconnected way to create a more digital, Internet of Things (IOT), cloud computing-based approach to airplane health monitoring.

The central processes for airplane health monitoring today are mostly the same as they were 10 to 15 years ago. Onboard maintenance computers generate fault messages about safety-critical systems such as engines, thrust reversers, auxiliary power units and more.

What’s changing and evolving is the use of smarter sensors with the capabilities of storage and internal processing, as well as easier access to leveraging cloud computing, IOT, data analytics and custom algorithms and application programmable interfaces (API) that give airlines the ability to operate their fleets in the most optimal way.

What Airlines are Doing

At the 2017 Paris Air Show in June, Airbus and California-based software services company Palantir announced a partnership for airlines to start monitoring the health of their airframes in a new way. The two companies unveiled a platform called Skywise, which is a cloud-based computer technology that has become the new single access point to work orders, spares consumption, components data, fleet configuration and on-board sensor data for every individual Airbus aircraft type. Operational interruption history, parts replacements, post flight reports, pilot reports, aircraft conditioning monitoring reports, technical documentation and service bulletins — all of which traditionally have been hosted on isolated servers — are now going to be available to airline maintenance technicians through a singular API that gives airlines the ability to make their own decisions about fixing or replacing parts or operating airplanes in a different way based on all of the available data.

EasyJet, in collaboration with Airbus, created a data repository that can accept data from its entire fleet.Photo courtesy of EasyJet

Gary Smith, head of engineering for EasyJet, said the U.K.-based low-cost carrier has, in collaboration with Airbus, created a data repository that can accept data from its entire fleet. The platform can also combine that data with other sources, such as EasyJet’s maintenance and flight operations systems. Previously the airline’s main process for gaining insight on failing or deteriorating parts or systems was to look for fault patterns on board, then send a notification off-board. Now, they’re able to take all the data off the aircraft and do the processing and fault detection “on the ground,” said Smith.

“For example, if we have a problem with engine vibration — we previously only reported engine vibration levels during take-off and cruise — whereas now we can do this throughout the flight,” said Smith. “This has already triggered a number of alerts that we have acted upon. With Airbus and Palantir, we have data from a wide range of systems and are able to use the known faults to ‘reverse engineer’ predictive maintenance alerts. We can look at the fault, work out what causes it, identify the adverse behavior and how this would be detectable from the data — and then write an algorithm to detect all of this. That is what we save and is constantly running against all the data across all the fleet.”

EasyJet flies to more than 130 airports, but only has maintenance and spares located at 35 of them. Therefore, being able to predict faults means that they’re able to perform necessary maintenance at one of their main locations versus having the airplanes fly to a location with no support and discover a major issue that could cause a flight delay. Smith said the airline focuses on monitoring its list of the top 100 faults that that could cause technical disruption.

Malte Kriszun, fleet engineer for Swiss Airlines, described the main health monitoring feature on their new Bombardier C Series as using a centralized computer called a health management unit, which is connected to the aircraft systems as well as the air data computer, and generates flight data and reports, such as those for the engine and troubleshooting.

“For continuous monitoring (independent from a turnaround), we generate about 30 MB of flight data and 30 to 40 MB of reports, hence about 60 to 70 MB per flight in total,” said Kriszun. “During a turnaround, the post-flight summary and generated status messages will be looked at.”

As operational hours continue to build up, the European carrier and Bombardier will gain a better understanding of what systems and components generate certain types of faults on a regular basis. The C Series is powered by the Pratt & Whitney geared turbofan engine, equipped with 5,000 sensors capable of producing up to 10 GB of data per second.

Swiss Airlines also has a fleet of Airbus, Boeing and Avro aircraft.

Photo courtesy of Swiss Airlines

“Airbus and Boeing both have their own Health Monitoring Systems. It generally works in a similar fashion, but differs in details. On the C Series there are additional reports (full flight reports) that the others do not offer which give us more opportunities to analyze. Retrofitting on Boeing and Airbus is not necessary as it is standard equipment,” said Kriszun.

AHM in the Future

Matthew Evans, vice president of digital transformation for Airbus, says the OEM sees Skywise continue to expand in applicability and customization as more airlines start using it. Skywise as a platform provides the foundation for the future of airplane health management for Airbus operators. Currently, in addition to the core Skywise platform, airlines that purchase it also get access to the Airbus flight operations and maintenance exchanger (FOMAX) tool for A320s and A330s. FOMAX provides access to the full range of sensor data available on both families of aircraft: facilitates access to over 40 times as many on-board sensors for better predictive maintenance, a richer view of ground operations, and optimal flight operations. Airbus plans to add new tools and dashboards to Skywise as more “airlines and ecosystem players join the platform.”

“By the end of 2018, the full Airbus Customer Service digital suite, including NAVBLUE applications, will run on the Skywise platform,” said Evans.

According to Evans, prior to Skywise, access to massive on-board data streams was only available on Airbus airframes that were being flight tested. Compared with flight-test aircraft, operational aircraft transmitted to the airlines “less than 2% of the data collected,” he said. Once entry-into-service was complete, the majority of engineering teams moved on to other tasks, as there was little operational feedback available to improve designs.

“Fortunately today with Skywise, operational data including maintenance records and on-board sensors is available to both airline and Airbus engineering teams. They collaborate seamlessly on a shared platform to resolve operational challenges quickly, to develop and deploy robust predictive alerts that minimize disruptions, and finally to implement root-cause fixes that eliminate issues. All four Airbus Commercial Aircraft families benefit from collaboration on Skywise; the fleet improvement process continues to accelerate,” said Evans.

Outside of the work Airbus is doing at the airframe OEM level, suppliers to all of the major aircraft OEMs are researching and introducing new technology to help further optimize the overall airplane health monitoring process. For example, Honeywell just introduced its new Integral Health Monitoring (IHM) series proximity sensors that can detect when a sensor has been damaged or otherwise impacted, and have the ability to detect most internal failures and display a fault output to a pilot or maintenance worker. On the engines side, Pratt & Whitney’s new eFAST system on the PW1500G-powered C Series captures 5,000 engine and aircraft parameters and 4 million data points during a typical flight.

Regardless of what new technologies and concepts OEMs introduce, one thing that will remain constant is that airlines will continue to evolve the way they monitor the health of their airframes, according to EasyJet’s Smith.

“We have a development roadmap over the next year which involves merging all the different elements of the work done so far into a common platform; we are also looking at how we equip the fleet to a common standard as the capabilities of the latest aircraft are much greater than the oldest aircraft,” said Smith.