S7 has learned to repair the most popular engine.
Having lost the support of foreign aircraft engine manufacturers due to sanctions, Russian airlines are trying to expand their repair capabilities. As Kommersant learned, S7 Technics has mastered a complex type of overhaul of the CFM56 engine installed on the most popular Airbus A320 and Boeing 737 aircraft. Due to the lack of competition, experts believe, the company has a chance of receiving orders from Russian carriers. Today they mostly just replace such engines with aftermarket ones. However, there is no longer enough used equipment, and prices are high, especially for the Russian Federation.
S7 Technics (part of the S7 Group) has mastered the most complex type of overhaul of aircraft engines CFM56-5B and 7B used on aircraft of the Boeing 737 and Airbus A320 families, sources in three airlines told Kommersant. According to them, S7 Technics plans to provide the service for other carriers. In total, there are about 800 CFM56 engines in Russia, the largest operator is the Aeroflot group. The sanctions deprived Russian aviators of support from manufacturers.
According to one of Kommersant’s sources, now carriers have almost no opportunity to export equipment abroad for overhaul and they, as a rule, resolve the issue by purchasing used engines. A number of types of repairs have traditionally been carried out in the Russian Federation, but the most complex work associated with the restoration of the hot part has not been mastered.
As one of Kommersant’s interlocutors clarifies, S7 will provide services for the overhaul of low-pressure turbine (LPT) modules, low-pressure compressor (LPC) modules and the hot part - the gas generator.
S7 is already engaged in the overhaul of the Honeywell 131-9A and Honeywell 131-9B auxiliary power units (APUs) for the Airbus A320 and Boeing 737, respectively. According to materials from the Federal Air Transport Agency, in 2024 S7 received permission to overhaul the Honeywell RE220 APU for the SSJ 100.
S7 confirmed to Kommersant that they began repairing the hot part of CFM56-5B and 7B and since October 2022 have completed 12 overhauls in the S7 Technics workshop in Sheremetyevo: “The aircraft are successfully operated in the fleet of Russian airlines.” S7 added that since 2015 they have been engaged in local repairs of the CFM-56: disassembling the engine to eliminate the defect, followed by assembly and replacement of compressor blades, turbines, and combustion chambers. In total, more than 300 repairs were carried out in Domodedovo and Minvody, S7 clarifies. In the future, they are considering creating a stand for testing engines after major overhauls.
Aeroflot, Ural Airlines, and Utair did not provide comments. According to a Kommersant source in the industry, overhaul of LPT and LPC CFM56 in Russia can take 70–80 days. The cost, according to him, will be comparable to prices abroad “and lower than the purchase price” of a used engine. One of Kommersant’s interlocutors estimates the cost of CFM56 on the secondary market with a good residual life at $14–16 million; when imported into the Russian Federation, the price can reach $18–20 million. Another Kommersant source assures that CFM56 can be found for $8–10 million
CFM56 is one of the most common engines in the world, notes Alexey Sinitsky, director of research and development at Infomost Consulting.
According to him, the model is known for its long service life: typical flight time, depending on operating conditions, is 40–60 thousand flight hours, or 10–20 thousand takeoff and landing cycles without removal from the wing, which is 8–12 years.
According to Kommersant’s sources, due to a decrease in production and an increase in demand for used engines, including from the Russian Federation, there is a shortage of CFM56 in the world, and it is especially difficult to find CFM56-7B for Boeing. The situation is aggravated by the increased repair time for CFM56 and the rise in cost of spare parts, clarifies Kommersant’s interlocutor on the European market. According to him, the duration of a simple C-check has grown from three to four months to more than eight months, and the most complex D-check, which lasted less than a year, can now take up to a year and a half.
The level of technology used in CFM56 “does not look prohibitively difficult for Russia,” believes the head of AviaPort, Oleg Panteleev. According to him, the first work in the country on CFM56 was undertaken by the then bankrupt Transaero, having mastered disassembling into modules ten years ago, which made it possible to send only the problematic unit abroad for repairs. Then the CFM56 repair competencies began to be developed at S7 Technics, long before 2022 having mastered more than 20 types of work and received approval from the developer.
But repairing the hot part is the most difficult type of work, notes Mr. Sinitsky. Legally, the development of such work is based on the generally accepted practice of DER repairs in the world, when approval is issued by the aviation regulator, and not by the manufacturer.
According to the expert, before the tightening of sanctions, the development of hot end repairs in the Russian Federation was considered inappropriate due to the high cost in the presence of foreign services.
Before the S7 sanctions, it was difficult to create demand for the most high-tech and expensive repair work, says Oleg Panteleev. Now, he believes, “due to limited competition, the company has a chance to receive orders from a wide range of domestic operators.” According to the expert, the A320neo and B737 NG families still form the basis of the narrow-body fleet of the Russian Federation.
https://www.kommersant.ru/doc/6690483