Russia has decided to develop a 26-ton-thrust engine, designated PD-26, based on the 35-ton-thrust-class PD-35 that is already under development.
In an interview with TASS on the eve of the Eastern Economic Forum, Russian First Deputy Prime Minister Denis Manturov announced that the new heavy engine will deliver 26 metric tons of thrust. It is intended for use in military transport aircraft and, in the future, for a wide-body passenger jet.
Russia’s intent to develop a 26-ton variant of the PD-35 may disappoint Russophiles, as it might seem a lesser achievement than completing the 35-ton version. However, the decision is based on sound logic rather than technological limitations.
PD-35 Development
The Minister of Transport of the Russian Federation, Andrei Nikitin, recently inspected the PD-35 technology demonstrator engine mounted on a testbed during a working visit to the Perm Territory.
The PD-35 is the first Russian-developed engine with a thrust of 35 tons, created under the High-Thrust Aircraft Engine Development Program. The first stage of testing was successfully completed in 2024, during which the engine demonstrated stable operation at its design thrust of 35 tons.
Designed to power advanced long-range wide-body aircraft, the PD-35 is a high-bypass, twin-spool turbofan featuring an exceptionally large 3.1-meter fan and a bypass ratio of about 11:1. It offers 2–5% lower specific fuel consumption than comparable Western engines while significantly reducing noise (17–20%) and NOx emissions (50–60%).
Like other advanced technology products, President Vladimir Putin personally monitors the development of the PD-35.
In March, during a meeting with Dmitry Makhonin, the governor of the Perm Territory, Putin inquired about the production of the PD-35.
A light-hearted exchange followed: alluding to the challenge facing UEC-Aviadvigatel’s general designer, Alexander Inozemtsev, in developing Russia’s first high-thrust engine, Makhonin remarked, “Alexander Alexandrovich (Inozemtsev) is now worried about this project.” Putin quipped, “He will succeed.” The President then asked the governor to convey his greetings to the designer, to which Makhonin replied, “Definitely.”
On the sidelines of SPIEF-2025, UAC head Vadim Badekha told Rossiya-24 that the corporation is considering the development of a twin-engine, more fuel-efficient Il-96 powered by the new Russian PD-35 engines.
Currently, the wide-body, long-range Il-96 is powered by four Aviadvigatel PS-90A1 turbofan engines, each rated at 17.4 tons of thrust. The Il-96-400M is a stretched and modernized version of the Il-96-300, which uses four baseline PS-90A engines.
Why The PD-26?
Using the gas generator of the PD-35, Russia can produce engines of varying sizes. In the past, PD-24 and PD-28 variants have been mentioned in presentations.
Alexander Inozemtsev, the general designer of PD-35 manufacturer UEC-Aviadvigatel, states that scaling up the gas generator by 15% could enable a thrust of 50 metric tons, if required.
Russia developed the PD-35 to power the Chinese-Russian Comac-UAC CR929 wide-body airliner, which was designed around an engine with a 35-metric-ton thrust.
However, Russia withdrew from the CR929 project due to Western sanctions, China’s refusal to de-Westernize the project, and China’s ambivalence about which engine would power the aircraft for the Chinese market.
As things stand, the PD-35, as originally conceived, has yet to find a market.
How Will Russia Use The PD-26?
Russia is reportedly developing a heavy airlifter to succeed the Antonov An-124-100 super-heavy transport, capable of lifting a 120-metric-ton payload.
The Russian Aerospace Forces currently have 26 An-124-100 airlifters in their inventory, each with a payload capacity of 120 metric tons. However, only about a dozen are reportedly operational.
Russia’s Special Military Operation in Ukraine has dramatically increased the requirement for military airlifters. The Russian Air Force’s medium-airlift (60-metric-ton) Il-76MD fleet is stretched thin. The need for additional heavy airlifters is acute.
The An-124-100 is currently powered by four Soviet-era 24-ton-thrust-class Progress D-18T turbofan engines.
The D-18T was created in the early 1980s specifically for the An-124-100 by Ivchenko Progress and was produced by the Motor Sich plant, both located in Zaporizhzhia, Ukraine.
In 2014, after Crimea seceded from Ukraine and joined Russia, Ukraine withdrew support for Russian D-18T turbofans.
In 2016, the Ural Civil Aviation Plant (UZGA) in Yekaterinburg, Russia, began overhauling D-18T turbofans domestically. UEC is locally producing many components of the engines and has successfully modernized the engine.
During a visit to the Aviastar plant in Ulyanovsk in October 2024, Russian Defense Minister Sergei Shoigu announced that the number of operational An-124-100 would be doubled by 2025.
UZGA is reportedly executing a three-year contract for 60 D-18T engines in order to meet this target and operationalize the aircraft awaiting repairs. Before the Special Military Operation, UZGA was overhauling one aircraft per year.
While inspecting the renovation of an Antonov An-124-100 with Military Transport Aviation Commander Lt. Gen. Vladimir Benediktov and United Aircraft Corp. (UAC) head Yuri Slyusar, Shoigu asked whether the D-18T would power the “hundred” aircraft.
Responding to the question, Benediktov said that two options are being considered—a modernized D-18T and a new PD engine.
It is likely that the “hundred” aircraft reference was to the Il-100, and Benediktov’s PD engine reference was to a 26-ton variant of the PD-35 engine.
Il-100
The Ilyushin Il-100 is a proposed super-heavy military transport aircraft developed under Russia’s PAK VTA (Prospective Aviation Complex for Military Transport Aviation) program. It is nicknamed Slon (Russian for “Elephant”).
According to Aviation Week, in May 2022, UAC-Ilyushin employees filed a patent in Russia for the design of a “super-heavy military transport aircraft,” with the Russian defense ministry as the owner. The aircraft is likely the Il-100 airlifter.
Its configuration is typical of heavy transport aircraft and similar to that of the C-17—a four-engine, high-wing monoplane with a T-tail. It has a standard rear-door ramp and an upward-hinging fuselage nose.
The UAC press release covering Shoigu’s visit to Ulyanovsk refers to the engine options as “either a modernized D-18T or PD-35,” even though the accompanying video showed Benediktov saying D-18T engines or “new PD engines.”
It is, however, clear that a four-engine configuration with 35-ton-thrust PD-35 engines would be overkill.
Most likely, Russia will develop the Il-100 using modernized D-18T engines, allowing time for the development of the PD-26. Serial-production aircraft would use the PD-26. It is also possible that the An-124-100 airlifters still in service will eventually be retrofitted with PD-26 engines.
- Vijainder K Thakur is a retired IAF Jaguar pilot, author, software architect, entrepreneur, and military analyst.
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