During the summer of 2017, the Central Aerohydrodynamic Institute (TsAGI) announced that it was working on a replacement aircraft for the Antonov An-124-100. Designed during the 1980s by the Antonov design bureau in what was then the Soviet Union, the plane is a four-engine strategic airlift aircraft.
The plane was the second-largest transport aircraft in the world after the Antonov An-225 'Mriya.' Sadly the Mriya was destroyed during the first weeks of Russia's invasion of Ukraine in 2022, leaving the Antonov An-124-100 to become the largest cargo airplane flying today.
The new aircraft the Russians are working on is called the An-124-102 Slon (Elephant) and will be built at the Aviastar-SP factory in Ulyanovsk next to the River Volga. The stipulations for the plane are that it must be able to carry five light tanks, 100 crew, and 300 fully armed soldiers up to 4,100 nautical miles.
The new plane may have folding wingtips
More recently, people working on the project have discussed how the new cargo plane may have folding wingtips similar to the Boeing 777X. By reducing the aircraft wingspan, it will be able to work out of more airports while still being able to increase its efficiency and size.
The downside, however, is that the wings would require some kind of folding mechanism. This would add to the plane's weight and also make it more expensive to manufacture. It is also understood that making the plane lighter by using more composites is a priority, as is an increase in aerodynamic performance.
New PD-35 engines will power the Slon
The engines for the new military transport will most likely be Aviadvigatel PD-35 high-bypass turbofan engines that are currently being developed by Russia’s United Engine Corporation (UEC). The PD-35 is a larger modified version of the PD-14, which is being developed to power the MC-21 twin-engine airliner.
The bigger PD-35 is intended to compete with the Rolls-Royce Trent 1000 and General Electric GEnx engines and could very well be used on the joint Russian Chinese CR929 long-range twinjet widebody, especially given the raft of sanctions recently applied to Russia.
When speaking at last year's Perm National Research Polytechnic University (PNRPU), Alexander Inozemtsev, a chief engineer at UEC, said the engine's development was delayed. The reason he gave for this was that they needed to allocate more resources to the company’s other PD-14, PD-8, and PS-90A engines. Initially, the engine was supposed to be ready by 2027-2028, but this has now been pushed back another two years.
Sanctions and the war is delaying the Slon's development
Last September, Chinese media reported that China was completely redesigning the engines for the CR929. This was due to Western sanctions placed on Russia following the invasion of Ukraine, likely the reason behind the PD-35s delay as well. Indeed, Russia's involvement in the CR929 project is in doubt due to recent sanctions and changes.
It is obvious that certain Western-made parts were needed for the engine, and now they are unavailable. With the ongoing war between Russia and Ukraine, it is very unlikely that we will see the An-124-102 Slon completed this decade. For the time being, the Russian military will have to rely on the few An-124s that it has and other planes like the Ilyushin Il-76 for transporting troops and equipment.
What do you think about the future of the Slon? Let us know in the comments.