Russia's S7 To Close CFM56 Blade Repair Shop

Russia's largest private airline group S7 is closing its subsidiary S7 Space, which had developed expertise in repairing the high-pressure compressor blades in CFM56 engines.

Parts of S7 Space will be absorbed by S7 Engineering, a part of S7 Technics MRO provider, according to a document on the website of Russia’s national tax service.

Speaking to Aviation Week, Andrey Balashov, head of the process engineering department at S7 Space, says the reason for S7 Space's closure was the high cost of its engineering efforts. It had used reverse engineering to master from scratch the so-called “restricted” engine component repairs that can normally only be performed by the original manufacturer, he says.

The blade repair process included cleaning off carbon deposits, robotic buildup of the worn section, subsequent CNC machining and final surface finishing, dimensional, dye penetrant and X-ray inspection, heat treatment, strengthening and final quality control of the finished part.

In December 2024, S7 Space received its first orders from parent S7 Technics and Russia's Aurora Airlines to repair 80 stage-four CFM56 blades at its facility near Moscow. In the spring of this year, it completed repairs on 80 stage-five and stage-six blades. The latest batch consisted of 400 blades from stages seven, eight and nine.

In terms of quality, S7 Space had surpassed some OEM-licensed repair facilities, Balashov claims.

“We had plans to repair several thousand blades per year,” he says, adding that they had also mastered component repairs for Honeywell 131 auxiliary power units on A320-family aircraft.

He confirms that all the equipment from S7 Space’s production facility will be handed over to S7 Technics’ engine repair shop at Moscow Sheremetyevo Airport. But the MRO provider only plans to continue with repairs that OEMs are willing to delegate to third-party companies.

Since October 2022, S7 Technics has completed 22 overhauls of CFM56 engines and their key components, the group says.

S7 Space was set up in 2016 to run the Sea Launch rocket project. After political issues hamstrung that venture, the unit in 2022 pivoted to developing CFM56 blade repair capabilities after sanctions cut Russian airlines off from Western MRO providers.