Sensors and sensibility keep today’s jet planes working hard

Jet engines in passenger and freight planes may seem the antithesis of the digital economy. Complex and costly, they are powered by old-fashioned polluting fuels: high-octane hydrocarbons.

But aero-engine makers’ emphasis on improving safety and reliability has led them to become the pioneers in the internet of things. They have connected industrial systems to electronics to produce detailed reports on their engines’ performance.

Twenty years ago, Rolls-Royce introduced its Total Care package, as part of which it provided maintenance to customers using information from digital sensors.

As a result, Rolls-Royce and rivals such as Pratt & Whitney know more than most about the challenges and opportunities presented by the internet of things. Other sectors can learn from their experiences as they adopt a more technical approach.

The big challenge is sifting the mass of information that sensors produce, to recognise serious problems and discard the insignificant. Such analysis offers the chance to boost efficiency, reliability, cost-effectiveness and design. Using this information, the manufacturers can offer more predictive maintenance.

Andrew Charlton, a Geneva-based aviation consultant, says maintenance crews generally notice problems in flight and can prepare a fix even before the aircraft lands, reducing delay and increasing aircraft availability.

“There are massive savings if you can pre-emptively perform maintenance on these aircraft during a stop,” Mr Charlton says. “The more you know . . . the faster you can fix it and get it back out on the plane.”

There are massive savings if you can pre-emptively perform maintenance on these aircraft during a stop

A similar approach is being applied elsewhere in the transport sector. About 100 trains made by Siemens of Germany, ranging from high-speed trains in Russia to electric locomotives in the US, use the company’s Railigent digital system. This helps to avoid trains being taken out of service unexpectedly by monitoring their sensors.

Eva Azoulay, vice-president for engine services at Pratt & Whitney, says would-be adopters of the technology should consider the “value proposition”.

The aeroplane and the engine are an expensive piece of equipment, she says. “You want to make sure you’re getting maximum value out of it.”

Digital sensors monitor temperature, fuel flow, air flow and pressure, which together give a snapshot of aero-engine health.

Tom Palmer, senior vice-president for services at Rolls-Royce, says the company enhanced its offering when it began selling engines under its Power by the Hour service agreement. Under this, Rolls-Royce takes responsibility for day-to-day service planning and performance, using sensors to detect problems.

“Taking on the same kind of liabilities that our customers are exposed to has dramatically improved reliability,” he says. “There’s a virtuous circle about collecting data from customers and using that information to help drive information for service products.”

Engineers used to service an engine after a set number of hours but now they intervene at exactly the right time.

Ms Azoulay says: “The idea of this capability is . . . that you see things coming, you can access the plane and do some limited work that will let the engine stay on-wing and continue to fly, which is what our customers want.”

The capabilities of real-time monitoring have increased with both the proliferation of sensors and the ability to gather information more regularly. Ms Azoulay says the company’s latest engine, the PW1000G, has 40 per cent more sensors than the V2500, which came into service in 2008. Performance data that were relayed twice in a flight can be sent every 2.5 seconds.

According to Mr Palmer, Rolls-Royce uses its data partly to help customers to improve how they use its products. It advises them on keeping fuel consumption to a minimum or reducing the risk of equipment failure. “We’re moving now to something that’s far more focused on customers’ outcomes [such as]: ‘Will the aircraft take off on time?’”

According to Ms Azoulay, increased data collection has been invaluable in addressing snags with the PW1000G, delays to which are said to have held up deliveries of Bombardier’s C Series jet. She says: “We were able to quickly understand the cause of the fault and make the technical changes in a very rapid window.”

Both manufacturers stress that the role of engineers remains vital. Rolls-Royce says it relies on engineers to sift the information most useful to customers; it never lets computers communicate directly with clients.

Ms Azoulay says the engineers’ analysis after a fault is a critical part of monitoring: “We look at all the data to see if we could have predicted it. Once we identify the elements that allow us to predict it, then you [can] look for that in future.”

Analysis is part of the steady improvement that real-time monitoring is bringing to the aero-engine business. Manufacturers are also offering retro-fitting of real-time analysis to older engines.

Meanwhile, new software that will flag problems should further improve systems’ capabilities. Ms Azoulay adds: “I automate it, so that I can effectively allow our customers to better operate their product.”