The pace of innovation in maintenance, repair and overhaul does not seem to be slowing down as OEMs, the airlines’ MRO subsidiaries and independent companies develop new devices and services. Additive layer manufacturing (ALM or 3-D printing), new coatings, improved engine washing and augmented reality are at the top of the list.
ALM, poised to be a major contributor to progress in MRO, is attracting startup companies looking for new opportunities to think out of the box. Bionic Production is one of them.
“We are offering spare parts production on demand,” Klaus Muller, senior advisor to the board, says. The software program Bionic Production uses has been inspired by the growth of organic cells. “Our designs are topologically optimized, just as nature evolved in a million years,” Muller says.
Already flying in Airbus A350 test flights are Bionic Production brackets for the crew rest compartment. The company expected to deliver its first 3-D-printed fuel connectors for the A400M in March. For such a fuel connector, using a conventional approach would involve 15 parts and 18 process steps, costing €10,000 ($11,000). Thanks to ALM, these numbers are reduced to one part, five steps and €4,000, according to the promoters of the technology. Benefits of 3-D printing also include a short turnaround time and reduced inventory requirements, Muller emphasizes. Moreover, parts can be produced locally. ALM is not suitable for large parts, however, as the machinery is limited to making parts no larger than 0.5 X 0.5 meters (1.6 X 1.6 ft.).
“We started production on Jan. 1; we are steadily increasing volumes,” Muller says. In March the company was to take delivery of a fourth machine. It is now “printing” from aluminum, titanium and stainless steel, as well as various plastics. “We are a strategic partner of Premium Aerotec,” Muller adds.
Bionic Production is very close to the Laserzentrum Nord research institute in Hamburg. Together, the two organizations also help other companies design their parts in a new way. They educate design engineers and provide design consulting for specific parts.
For a spare part where an existing design is just copied, no certification process is needed. Nevertheless, Bionic Production is in the final stages of being certified as a supplier by the LBA, Germany’s civil aviation authority.
Progress in ALM has been fast. Compared to five years ago, the process is more robust. Better quality-monitoring systems and intelligent software now allow efficient manufacturing processes at better cost. “The process is so robust and stable that we can manufacture parts for aviation,” Muller says.
Bionic Production expects improvements in powder manufacturing and machine performance as well. The process chain (including pre- and post-manufacturing phases) will be automated, Muller says. He predicts all phases will be linked in one software program, thanks to digitalization, from part design to post-processing. The speed of manufacturing is forecast to increase tenfold in the years to come.
Lufthansa Technik (LHT) appears close to making a reality a decades-long research pursuit (notably by Airbus). The so-called “sharkskin” coating will be on the market in 2017, says Helge Sachs, head of corporate innovation management and product development—a prediction consistent with one made in 2014. The idea is to imprint a structure of riblets onto the applied paint. The riblets make the airflow more laminar (i.e., less turbulent). Fuel consumption is thus cut by 1-2%.
“With partners, we are looking for the most efficient method to [modify] the painting process,” Sachs says. Lufthansa Technik is working with Airbus and aims to receive a supplemental type certificate. A new formula for the paint itself is making production possible, as a previously used ingredient was not environmentally sustainable.
“We are focusing on the wings, and the horizontal empennage, as it is easier to have riblets on a horizontal surface,” Sachs explains. A specific robot, for a process that will be more automated than today’s painting techniques, will imprint the riblets on the upper layer of the paint.
Such a coating would last five years on a new or retrofitted aircraft. A series of tests flown on an Airbus A340-300 has shown the paint is durable in tough environments.
Still being optimized is the height of the riblets, on the order of 40-60 micrometers. In the longer term, heights could vary, depending on the proximity to the leading and trailing edge. In any case, at such tiny scales, riblets can be felt with a fingertip but hardly can be seen. The livery’s appearance, however, might not be as shiny as it is today, but Lufthansa Technik is confident it will find a solution for that.
Another project involves using a new way to wash an engine, with CO2 dry-ice pellets. Sachs says LHT is investigating this and thinks it could be brought to the market in a year or so. Conventional engine-washing is recommended twice a year to keep exhaust gas temperature (EGT) margin, and thus fuel efficiency, nominal. But doing so in winter has so far been problematic because conventional washing uses water. Adding a third washing would be beneficial, Sachs says, and Lufthansa Technik may have found a way to do that without any risk of icing.
Injected into the engine air intake, the dry-ice pellets hit the blades of the compressor stages. The kinetic energy and the temperature (-78C, or -108F) shrink the dirt, make it brittle and then remove it.
The dry-ice jet spray itself does not leave any waste product behind. Another benefit is the shorter on-ground time—50% less than Lufthansa Technik’s current Cyclean services.
Also being investigated is how to remove those particles that melt in turbines in sandy areas.
In information technology, Lufthansa Technik wants to make the most of the Internet of Things. “This is the fourth industrial revolution: connecting every device—tools, testbeds, components and spare parts—to the ‘industrial’ Internet through QR coding, RFID, etc.,” Sachs says. This is good for managing inventory, as the location of a part can be known at any time.
This should be good for prognostics, too. “One day we will be able to much better predict when a part will fail,” Sachs says. For example, in a low-pressure turbine operating in sandy conditions, a part will be replaced in advance or repaired (with laser welding) exactly at the right time.
Wearable Augmented Reality
Engine MRO specialist TAE is offering Fountx, a wearable augmented-reality system that enables a remote expert to support a technician in real time. The system comprises an operator headset and an expert station.
The headset includes a near-eye display, which does not affect the user’s spatial awareness, according to TAE. A camera provides the remote expert with immersive communications. An Australian-based research organization, Csiro, was involved in Fountx’s design.
Fountx uses intuitive gesturing. Because the technician can see the remote expert’s hand gestures, the latter can point to the object on which to focus “or give an indication of which way to turn an object,” says Greg Twiner, senior business development manager. “Even a simple ability to give a ‘thumbs up’ can communicate a lot without the need for verbal connection—something that could be critical in some environments,” Twiner says.
The system also enables the remote expert to mark up the image the technician is viewing, for example by circling areas or using pointing arrows. The expert just uses his or her hands and a touch screen.
Major MRO service providers are structuring the way they innovate. Air France Industries-KLM Engineering & Maintenance (AFI KLM E&M), the MRO branch of Air France-KLM, recently launched its “MRO Lab Singapore.” The innovation center, an addition to a similar organization in Europe (see page MRO 4), is being formed jointly with Ramco, a supplier of software for the MRO sector. Ten people are working at the MRO Lab Singapore to design and develop “innovative, rapid-deployment solutions.” AFI KLM E&M thus wants to co-develop products with its Asian customers and, to a wider degree, is targeting an Asian “ecosystem” of companies, says James Kornberg, director of maintenance and engineering innovation.
Methods in MRO innovation are undergoing a swift evolution. AFI, for example, is hiring experts in user experience, robot programming and artificial intelligence. Trying to develop numerous ideas, even ones that lead to quick failures (“the quicker, the better,” Korn says) is encouraged.
Using such rapid-prototyping practices, AFI KLM E&M has developed an application that synchronizes technician-taken photos with the repair order’s file. Part of a process that checks the part’s condition, the app reduces the sync time to seconds.
Lufthansa Technik started in 2014 to “professionalize” its innovation process. A central team steers all innovation activities, to which 200 people are dedicated. Its overall budget of €200 million is spread over five years, 2014-18. More than 60 projects are ongoing, according to Sachs. They involve collaborating with research institutes in Germany and Europe as well as startup companies such as in the Starburst Accelerator.
Engine manufacturer Snecma is using rapid-prototyping methods, like those usually found in a fab lab, to devise new services (MRO Edition Feb. 1-14, p. 20). Involving final users in a co-design process, one of the first creations has been real-time support for a borescope inspection.