Moscow’s Central Aerohydrodynamic Institute (TsAGI) – the centre of Russian research on aerodynamics, and a key institution in the development Russian aircraft since its foundation by Nikolay Zhukovsky in December 1918 – says that Russia has completed preliminary design work on a new giant cargo aircraft to replace the Soviet era AN-124.
The AN-124 with its ability to ferry 150 tonnes of cargo over 3,200 kilometres is the largest and most powerful cargo aircraft in current service. However it was designed in the 1970s and is now showing its age.
Also the AN-124 is the offspring of the Antonov Design Bureau based in Kiev in what is now independent Ukraine, and its Progress D-18T turbofan engines are built by the Motor-Sich factory in Zaporozhye in Ukraine.
As the AN-124 becomes increasingly old its maintenance needs are increasing, and the conflict with Ukraine means Russia can no longer easily source engines or spare parts for it.
The need for a new big cargo aircraft to replace the AN-124 for both civil and military uses is therefore becoming pressing, and it has been known for some time that the Russians have been working on such an aircraft.
TsAGI has not disclosed the identity of the design bureau that is responsible for this aircraft, but it is almost certainly the Ilyushin bureau which is becoming the main design centre for Russian large transport aircraft projects.
The new cargo aircraft (pictured) looks similar to the AN-124 but is actually bigger and has a longer range.
Allegedly it will be able to ferry 150 tonnes of cargo over 7,000 kilometres (twice the distance of the AN-124 with the same load) whilst the maximum load will increase from the 150 tonnes of the AN-124 to 180 tonnes for the new aircraft, which the new aircraft will however be able to ferry over a distance of 4,900 kilometres.
This is a significant upgrade in performance over the AN-124.
This is consistent with the demands of Russia’s leading air freight specialist Volga-Dnepr – the main civilian operator in Russia of the AN-124 – which says that any new aircraft replacing the AN-124 should be at least 30-40% more efficient than the AN-124. Advances in technology since the An-124 was designed in the 1970s make that possible.
The new cargo aircraft will achieve its greater efficiency by using in its structure the stronger and lighter materials which have become available since the AN-124 was designed in the 1970s, and by using a newer and significantly more powerful and efficient engine than the D-18T used by the AN-124.
The new engine will almost certainly be the new Kuznetsov PD30 geared turbofan which is reported to have a rating of around 35 tonnes of thrust (roughly a third more than the D18T).
The Kuznetsov PD30 is known to be in advanced development for use on the new Russian-Chinese wide-bodied aircraft, which will carry two. The illustration of the new Russian cargo aircraft released by TsAGI shows it will have four.
Combined with a lighter and stronger structure because of the use of new materials, four Kuznetsov PD30 engines – more powerful and more efficient than the AN-124’s D18T engines – will ensure that the new aircraft is able to meet the performance targets.
The Russians have spoken in the past of a programme entitled “Prospective Airborne Complex of Transport Aviation” or PAK-TA, which is intended to provide the air transport division of the Russian Aerospace Forces with a family of new large cargo aircraft.
It seems that at least two aircraft are being developed, and that these will share components and sub-systems with each other, making their design and construction simpler, and simplifying the logistic and maintenance burden.
The smaller of these aircraft will apparently take the form of a revived version of the IL-106 project of the 1980s, and will be able to carry payloads of 80-100 tonnes using four of the new PD-18R geared turbofan engines, which have 20 tonnes of thrust each.
The second is the larger aircraft details of which TsAGI has just revealed, which is designed to carry payloads of 150-180 tonnes using four of the new PD-30 geared turbofan engines, with 35 tonnes of thrust each.
Both of these aircraft appear to be conservative designs posing few technical challenges for an industry which has extensive experience of designing and building large transport aircraft.
Given the availability of the new engines to power the new, they should not be especially expensive or complex to design or build.
The factory tasked with building them will probably be the Aviastar factory complex in the Volga city of Ulyanovsk.
Production will probably begin in earnest in the early 2020s, as sufficient numbers of the new PD18R and PD30 engines become available, with service entry apparently intended for 2023.
The Russians have now provided us with a glimpse of what the larger aircraft will look like. Apparently the Russians have already given it a nickname: “Slon” meaning elephant.