MIAMI—Engine manufacturers are leaning heavily on their approved overhaul shop networks shops to help meet unexpected demand on current generation engines, but restrictions on repairs and other licenses continue to create headwinds.
“There used to be no issues on sharing information,” Delta TechOps VP-commercial Basil Papayoti told AeroEngines Americas attendees Feb. 29. “Boy, has that evolved over the years.”
Papayoti underscored that Delta Tech Ops has strong relationships with GE Aerospace, Pratt & Whitney, and Rolls-Royce--all partners in different engine services ventures. But the nature of such agreements is changing.
“The [intellectual property] piece is huge, especially on the new-generation engines. That makes it really difficult for the independent” shops, he said. “It’s gotten to the point where it’s really restrictive,” he added, noting that Delta benefits from its status as one of the largest aircraft and engine purchasers.
Both CFM International and Pratt & Whitney tout a faster pace of repair development on the Leap and PW1000G geared turbofan (GTF) families, respectively, compared to their predecessors. This is due in part to the engines’ more complex materials and operating conditions.
But entry-into-service (EIS) durability and production issues have affected both families, reducing expected time on wing and forcing unscheduled engine removals. The GTF fleet has been more affected, overwhelming its still growing overhaul network. The Leap fleet has been less affected, but retrofits of a reverse bleed system to address fuel nozzle coking and improved high-pressure turbine blades will add to scheduled work beginning to ramp.
More work often leads to demand for more parts or repairs. Getting approved fixes into the field as quickly as possible will help minimize disruptions for operators. The need extends to legacy engine platforms such as the CFM56-5B/7B and the International Aero Engines V2500, which need more maintenance work to keep them on-wing to backfill gaps created by the new-engine issues.
“You can control as much as you want in terms of proprietary repairs, but that’s causing gridlock for a lot of this work,” said MTU Aero Engines North America VP Sales and Marketing Les Cronin. “The knock-on effect is that the new-generation entry-into service issues are causing the legacy engines to go to the shops as well, because people didn’t build in sufficient green time.”
One challenge both the Leap and GTF faced is the rapid escalation of their in-service fleets. Both saw in-service numbers ramp up more quickly than the CFM56 or V2500, even with pandemic and supply chain-related delivery delays. But the expansion of repair manuals, which leans heavily on lessons learned from early shop visits, has not been similarly accelerated. Mix in the added complexity incorporated into the newest engines—and related higher parts costs—and both manufacturers and MRO providers have an opportunity.
“It takes all of us to come up with ideas on how to fix parts, especially high-cost items,’’ said Lufthansa Technik Head of Sales-Engine Services, Americas Sebastian Torhost. “Get creative with all the engineering and all the experience from the previous engine types to come up with repairs. Maybe you can do this touch-up repair, maybe you can drill a hole a bit differently in order to stay within the limits.”
