With new engines needing ‘hospital’ shop visits and mid-life engines nearing their overhaul peaks, engine shop, spare and part supplies are stressed. One way of relieving at least shop stress may be more resourceful use of engine line maintenance capabilities.
Sven Taubert, head of corporate foresight and market intelligence at Lufthansa Technik, predicts the 2020s will see more mobile maintenance for engines and aircraft to reduce shop visits and ground times. Zoran Bozic, business manager for engine line maintenance at Magnetic MRO, would certainly agree.
“Twenty years ago, the common understanding was that engine line maintenance was about filter replacement, chip detector inspection, LRU changes, in other words, on-wing tasks that do not penetrate into the internal part of an engine,” Bozic says. These limits traced to hard-time maintenance concepts, with fixed shop visit intervals.
Now, new technologies, increased reliability, modular engine designs, on-condition maintenance and competitive pressures to reduce costs have changed the old rules. “There is no need to send an engine for combustion chamber replacement to a traditional engine shop, it can be done in line maintenance,” Bozic says.
Line MRO providers are now competing to offer more complex packages. In addition to combustion chamber replacement, airlines may want a provider to remove the engine, reinstall it, do a maximum power assurance (MPA) run and bring the entire aircraft back into service. “They do not have resources to shop around, and a one-stop solution is what they are looking for,” Bozic stresses. “Mobility and flexibility are the pre-requisites of successful engine line maintenance service provider.”
Mobile engine services in Europe are provided by traditional engine MROs such as MTU, Lufthansa Technik, Safran and Aero Norway that can bring complex capabilities such as module replacement and repair to airline sites. But Bozic argues these major MROs are limited in number and may seek filling shops, while making engine line maintenance a second priority.
The next tier of suppliers such as Magnetic does less complex line work, such as borescope inspections, boro-blending, and top-case repairs. “Flexible providers specialized in pure engine line maintenance are not that easy to find,” Bozic says.
But smart use of these kinds of engine line maintenance can be a big money saver, according to the Magnetic exec. He instances the borescope blend in-situ repair, or boro-blend. Magnetic was recently asked by a European flag carrier to do boro-blend repair of a high-pressure compressor on a CFM56-5B on an aircraft in for C check. While the Magnetic team was flying to the site, the airline discovered a similar need on another engine and aircraft. “Within less than 12 hours, both engines were repaired and released as serviceable,” Bozic says. “The cost for this service was several times cheaper than the second-best option, removal of engines, top case repair and reinstallation of the engines. We did it like a pit-stop in Formula One race.”