Tomorrow's problem, solved today

Pondering the future of business aircraft maintenance you could be forgiven for assuming it would be dominated by futuristic concepts, theories and very little actual practical operation. The reality is very different. Words Yves Le Marquand

CONNECTED AIRCRAFT are here now. GE Aviation’s Signature range features an average of 88 sensors per engine. Pratt and Whitney has derived and is analysing data from more than 835m fleet flight hours. Rolls-Royce’s recently released Engine Vibration Health Monitoring Unit (EVHMU) measures just over 10,000 different engine parameters. All of this means it’s never been easier to keep an aircraft in the air. Going are the days of regimented check-ups.

What do we mean by the term connected aircraft? Greg Ryan, sales director, GE Aviation tells Corporate Jet Investor (CJI): “Just like everything we do today in our lives, it’s all via the internet. Today’s aircraft and engines are the most technologically advanced ever. So, with the engine connected, we as the engine manufacturer can provide services and support in real time. It’s as simple as that. I always tell people we have finally moved engines into the 21st century and it’s the future of how aircraft will evolve going forward.”

88 SENSORS ON A GE PASSPORT

The GE Passport engine contains a total of 88 sensors which report back live to headquarters allowing GE's technicians to analyse data mid-flight and prognose part failure.

Why is this good for the customer? For GE Aviation, it is about two things: time and safety. “As we all know the aircraft is a time machine,” says Ryan. “So, when it’s down every second counts. The focus for us is to predict and be proactive and reduce the time to return-to-service.”

If GE receives a fault indication on one of its engines (on the ground, taxiing or mid-flight) it is immediately analysed by the firm's digital algorithms and then that information is further analysed by an engineer before any fault record is sent to the customer. That engineer will also then have the expertise to provide the customer with a solution. “No one has the ability to provide that level of service other than the engine manufacturer,” adds Ryan.

“It’s one thing to trouble-shoot, but when you have a cockpit warning on our aircraft, we are looking at it while you’re in the air.”

Steve McManus, GE Aviation

It is a crucial point Ryan makes. Today’s prognostic tools mean maintenance can be carried out on a client’s asset ahead of time. Really the connected aircraft serves to enhance the relationship between the customer and the manufacturer.

Steve McManus, sales director, GE Aviation tells CJI: “When you look at the safety and the time aspect, it’s one thing to troubleshoot, but when you have a cockpit warning on a connected aircraft, we are looking at it back at HQ while you’re in the air. With 88 sensors in a connected engine, one of the first things we check is that the sensors themselves aren't faulty. It could be giving a false signal and while you need that sensor changed, it’s no reason not to fly.”

A connected aircraft also improves the performance of the entire fleet, because as well as detecting the fault, a GE engine (installed on the Global 7500 for example) will learn from the experience too. Ryan explains: “It will provide that learned information to the manufacturer, which gives us the ability to spread that data through the entire fleet using some additional algorithms we develop from that initial data. This allows us to fix problems we haven't necessarily seen before.”

Now compare that to times gone by. On yesterday's aircraft when you had an event, the manual stipulated some form of maintenance – maybe you had to borescope the engine or change a certain valve before the next flight. However, you could be stuck in an area where there is little to no maintenance access. This could force you to fly mobile repair teams (MRT) in to repair your aircraft all at extra cost.

“However in a connected aircraft when we have the maintenance program, we can provide the fly-on limits, knowing the post-flight and the current-flight of that aircraft. We say: ‘Oh, we can give you two more cycles, because we know the limits of that engine,” explains McManus.

GE has made it a company mission to develop new technology-based improvements to its service and the pandemic has accelerated the pace of change, according to Karen Person, marketing manager, GE. “Covid really broke the mental inertia in a lot of areas, we’re seeing accelerating technologies. Things that would’ve taken a decade are now happening in months. So, it is really about bringing in the right suite of connectedness technologies to meet evolving customer needs.”

Whilst the idea of a connected aircraft remains a seemingly new idea (hence the name of this feature), OEM Pratt & Whitney Canada (P&WC) has been offering a form of what it calls Digital Engine Health Management services for more than 20 years.

ARTIFICIAL INTELLIGENCE INSPECTIONS

Rolls-Royce have been developing a mini snake robot which using Artificial Intelligence is able to work its way through an aircraft engine performing visual inspections on areas that are otherwise very difficult to reach without dismantling the engine.

The latest product in those services is called FAST, it’s a solution that provides near real-time, high-density, full-flight data after each mission. Satheeshkumar Kumarasingam, vice president, Customer Service, P&WC, tells CJI: “The solution goes beyond diagnostics and prognostics to give customers a fully connected, data-driven engine.”

The FAST system automates the capture and analysis of a wide range of full-flight engine and aircraft parameters providing wireless access to encrypted and secure flight data recorder (FDR) data.

“Unlike many avionics systems, which require manual intervention to off-load data from the aircraft, the solution enables wireless transmission after each flight and the ability to capture complete mission data – from engine start to shut down. Once armed with this crucial full flight data, P&WC can analyse and share it with customers and maintenance crews, so they have meaningful information at their fingertips within 15 minutes of the pilot shutting down the engine,” says Kumarasingam.

“No one knows our engine better than we do. We designed it, we know its reliability drivers and we know our customers.”

S. Kumarasingam, Pratt & Whitney Canada

The Global 7500 is powered by the GE Passport engine, incorporating advanced technologies and materials to improve durability, noise output and fuel consumption. GE's technicians are also monitoring the engine's health live to optimise your time on wing.

Like GE’s Passport range, P&WC’s FAST engines have tightened the relationship between OEM and customer. Kumarasingam explains that through the ability to deliver alerts and trend monitoring, “P&WC is more closely engaged with the customer, not only providing early detection of possible events, but also helping the operator to extract maximum benefit from the engines with the greatest cost-efficiency.”

“The system can also automate much of the onerous task of compiling carbon burn and other regulatory reports. This means more time on wing and higher rates of dispatch availability,” he adds. P&WC’s PW307 engines, which power Dassault Falcons have historically demonstrated a dispatch rate of 99.94%.

Kumarasingam says: “No one knows our engines better than we do. We designed the engine, we know its reliability drivers and we know our customers. We are also able to combine full flight data with different proprietary technologies, such as our Oil Analysis service and provide a 360-degree view of the engine health.

“It follows that as the originator of this increasingly complex and finely tuned technology, we are the best, most proficient, at maintaining it. There is always something to be said for the value of turning to the OEM for maintenance.”

In the case of aviation engines specifically, knowledge is power – a carefully monitored, well maintained engine retains its value longer. Perhaps most importantly, it ensures consistent and safe operation. When an aircraft is flying at 559mph (900kmph or 485 knots) at 30,000 feet, you want to know your engines are performing optimally at the moment – and well into the future.

“Also, by using engine data to address issues proactively, major problems can often be avoided totally, saving the customer potentially hundreds of thousands of dollars in engine repairs,” adds Kumarasingam.

Most aircraft disruption is caused by an accessory that sits outside the core of the engine – a fuel metering unit, handling bleed or starter air valve for instance. These are the issues that will stop you flying. Rolls-Royce’s senior vice president, Customers & Services, Business Aviation, Andy Robinson, tells CJI: “Now our engines can monitor those units and see them deteriorating and it enables us to take them off before they fail. Which ultimately means you should never have an aircraft out of operation. 100% availability is our goal.”

Rolls-Royce uses the term intelligent engine and the British OEM has invested heavily in what it calls a ‘Digital Twin’ a digital model of the engine and its original maximum capabilities – and proprietary technology. Its recently released Engine Vibration Health Monitoring Unit (EVHMU) transmits a continuous live feed of data from the aircraft which allows Rolls-Royce to compare with the digitised twin and detect any deterioration. Like Pratt & Whitney Canada and GE, Rolls-Royce engine users also benefit from the history and data of thousands of engines, which adds to the level of complexity built into the digitised twin. The firm has 70% of its fleet on corporate care, all of which transmit data back to HQ.

So, will there be a time when all aircraft are connected in this way? Robinson certainly hopes so, “I think we would love for there to be a time when we can get all aircraft connected. I think in business aviation people are learning the benefits of health monitoring. It’s not as mature maybe as it is in the airline world, but it is rapidly catching up.”

DIGITAL MONITORING ENGINE HEADQUARTERS

Rolls-Royce technicians monitor and then analyse digital data passed on from the engines. Data is not just a numbers game however, advanced sensor technology allows for visual representations to be inspected back at HQ.

Explaining the cost benefit to the customer is one way of ensuring accelerated uptake of connected aircraft and engines. Modern engines run on-condition whereas older engines are “hard-time”, meaning you would replace a component or part at a specific time. The modern engine can run until the OEM analysing the engine’s data senses that it is an appropriate time to replace it.

“With an on-condition engine you can understand how it is vitally important that we have this health data sent to us so we can monitor and understand how it is performing,” says Robinson.

The question that remains is where does the industry go next? With the development of diagnostic and then prognostic technologies an aircraft engine has never been so cutting-edge. But there is always room to evolve, in the field of robotics for example, says Megha Bhatia, vice president, Sales & Marketing, Business Aviation, Rolls-Royce.

“The super-connected intelligent engine roadmap can also benefit from robotic technology that, just a few years ago, would have existed only in the realm of science fiction. We are developing a snake robot that can work its way through an engine like an endoscope to deposit swarm robots that crawl through the insides of the engine and perform a visual inspection of hard-to-reach are-as,” Bhatia explains.

In times gone by, your aircraft would be in for hard-time checkups, having parts replaced that do not necessarily need replacing. Now, if you have an engine constructed in the past two years by any of the major OEMs that engine will feature a multitude of sensors. These draw data from every part of the engine allowing the OEM to analyse it through at least 10,000 parameters. Now as we see emerging technologies like swarm robotics become integrated into maintenance schedules, a world where engine time-on-wing is at its optimum and aircraft are never unavailable is a real possibility.