Russia sells Su-35 technology to China.

This information was revealed by the Russian news agency when it reported that Moscow had completed the contract by delivering the last five out of a total of 24 Su-35 fighter jets to the Chinese Air Force under a contract signed in 2015.

Sources from the Russian Defense Industry Association indicate that the contract was signed with a deadline of 2020, but the Russian manufacturer completed deliveries ahead of schedule.

What's special about this deal is that Russia isn't just selling aircraft; it may also be selling maintenance and repair technology – including replacement parts and training for Chinese pilots to switch to the new aircraft.

In 2015, after many tense negotiations, particularly regarding the quantity and licensing issues, Moscow and Beijing signed a contract for the supply of 24 highly maneuverable 4++ generation fighter jets, with a total contract value of approximately $2.5 billion.

Before Russian news agencies revealed that Russia had transferred some Su-35 technology to China, Russian and Chinese media outlets had repeatedly reported that half of the 24 Su-35s sold by Russia to China would be manufactured under license in China.

However, to date, all details regarding this matter remain unclear, but surprisingly, Russia has agreed to cooperate with Beijing in developing the engine for this type of fighter jet.

This information was provided by the Deputy Minister of Industry and Trade of Russia, Yuri Slyusarev, according to which Russia has decided to cooperate with China in developing a new jet engine based on the "117C product".

Along with supplying the Su-35 aircraft, Russia also wants to negotiate further with China regarding the technical aspects of the contract. It is known that Russia and China have been negotiating this procurement contract since the end of 2012, and the negotiations have been stalled over the years.

According to Vyacheslav Dzirkaln, Deputy Director of the Federal Service for Military-Technical Cooperation (FSVTS) of Russia, the deadlock in the contract stems from China's demand for changes to the Su-35's technical parameters before delivery. Meanwhile, Russia has no intention of making any major changes, either in appearance or technical aspects, to the export version of the Su-35.

Meanwhile, in mid-2014, Itar-Tass, citing Russian military sources, reported that the reason for the lengthy negotiations was that Russia had not yet equipped its air force with enough of these advanced aircraft, and there were some sticking points regarding the price.

The Su-35 fighter jet is a highly maneuverable Russian combat aircraft developed by the Sukhoi Design Bureau. This fighter possesses superior combat capabilities compared to other fighters of its generation and even fifth-generation aircraft, thanks to its highly maneuverable engines and state-of-the-art electronics.