Wednesday, 12 August 2015

Marshall Horn - The Resurrection of Russia's Aircraft Engine Industry

Marshall Horn,

The Kremlin has provided a transcript of an interesting meeting that took place between Putin and the Dmitry Rogozin, the deputy Prime Minister in charge of Russia’s defence industries.

Russia Insider has previously provided a profile of Rogozin. explaining to our readers who he is.

The meeting was to discuss development of gas turbine engines, the engines that are used to power aircraft and warships.

In order to understand the discussion some background is necessary.

As Rogozin says, the USSR was at the forefront of gas turbine technology, producing a bewildering range of powerful engines for its aircraft and warships and doing so moreover in prodigious numbers.

What Rogozin does not say is that in the late 1960s and 1970s the USSR fell behind the West in developing fuel efficient high bypass turbofans for civilian transport and passenger aircraft.  This was why the USSR was late in developing wide-bodied passenger aircraft to rival US aircraft like the Boeing 747, which entered service in 1969.  The nearest Soviet equivalent - the IL96 - only appeared in the mid 1980s.

As Rogozin correctly points out, the USSR never experienced the same lag in turbojet and low bypass turbofan engines such as are used by supersonic military aircraft.  Indeed with such engines as the AL31 used by the Su27 fighter, the RD33 used by the MiG29 fighter, the R25 used by later versions of the MiG21 fighter, and the NK32 used by the TU160 bomber, it was very much at the forefront of supersonic engine design.

The USSR was also a major leader in the design and production of the large and medium sized turboprop and turboshaft engines that are used by propeller aircraft and medium and large sized helicopters.  Examples are the massive NK12 used by the TU95 bomber, the D136 used by the heavy Mil26 helicopter, the medium sized TV3 engines used by the Mil24, Mil8 and KA27 helicopters, and the AI20 and AI24 engines used by AN26/32 family of medium sized transport aircraft.

Rogozin also fails to mention one other important fact, which continues to have a major influence on the Russian aircraft engine industry to this day. 

This was a decision made by the USSR in the 1960s to abandon development of small turboprop, turboshaft and turbofan engines, as used by light aircraft, small helicopters and business and training jets.  The USSR did this because, under arrangements agreed through the CMEA (“COMECON”) - the Soviet bloc’s equivalent to the European Economic Community - it was decided that development of such engines would take place in Czechoslovakia and Poland from whence they would be exported to the USSR.

It is the absence of small domestically produced turboshaft and turboprop engines which explains why - in contrast to the situation with medium and large helicopters and transport aircraft in the building of which Russia is a world leader - Russia fell so far behind the West in developing light helicopters and drones.

By the 1980s the USSR was catching up fast in high by pass turbofan technology.   An impressive range of new engines appeared: the large to medium sized PS90 engine for use on the IL96 and TU204 passenger aircraft, the big D18 aircraft used by the giant AN124 transport aircraft, and the smaller D36 aircraft used by the AN72/74 family of transport aircraft.

The collapse of the USSR significantly weakened Russia’s gas turbine engine industry, and as Rogozin says it has yet to fully recover.  

A key producer of gas turbine engines, the Motor Sich plant in Ukraine - producer of the D36, D18, AI20 and AI24 engines - was lost to the industry.  Engines produced by this plant, as well as gas related turbine engines used for warships,- many of which are also made in Ukraine - after 1991 were built in what had become a foreign country, and therefore have had to be treated as imported engines instead of being domestically produced ones.  Since the Maidan revolution of February 2014 Ukraine has imposed restrictions on the export of these engines to Russia, which are therefore no longer readily available.  Moreover production of the D18 - the USSR’s big high by pass turbofan, used by the giant AN124 transport aircraft and intended for use in bigger passenger aircraft that were being designed prior to 1991 - has apparently entirely stopped.  

The rest of the industry that remained in Russia stagnated through lack of funding.  Russia’s sole remaining high by pass turbofan engine - the PS90 - was never updated or developed in the way that a comparable Western engine would have been.  The number of PS90s produced until recently was anyway very small, and would not have justified work to develop it.

Supersonic engine production in the 1990s seems to have stopped almost entirely.  Production of the TU160 with its its giant NK32 engine was stopped.   Such production of the AL31 and RD33 fighter engines as took place seems to have been entirely for export, principally to India and China.   By common acknowledgement, manufacturing quality of these engines after 1991 declined markedly. 

Throughout the period from 1991 until the mid 2000s no serious design work on new engines seems to have taken place. The AL41 engine project for the country’s projected fifth generation fighter project appears to have been stillborn.

From a situation where prior to 1991 Russia produced all its own aircraft and engines (apart from light aircraft and engines imported from Poland and Czechoslovakia) Russia moved to a situation by the mid 2000s where it was importing almost all its passenger aircraft and engines from the West. Moreover because of the 1960s decision to transfer work on small turboprop and turboshaft engines to Czechoslovakia and Poland, as Rogozin said to Putin in their meeting, Russia has no domestic engines to power its light aircraft and helicopters, obliging it to import such engines from the West.

Since the mid 2000s the situation has slowly improved.  

The Russian military’s decision to order an updated version of the IL76 transport aircraft with PS90 engines means that this engine is at last being produced in significant numbers.

Development of Russia’s fifth generation fighter - the Sukhoi T50 - which finally began in earnest some time around the mid 2000s, allowed work on the next generation AL41 supersonic fighter engine to resume.  The decision to proceed with production of an updated version of the MiG29 fighter - the MiG35 - has led to a restart of production - and a deep modernisation  - of the RD33 engine.

Rogozin’s report to Putin has now provided more information about current projects, enabling an assessment of the current state and direction of the industry.  

In contrast to some of the more speculative stories about Russian aircraft and engine projects that appear from time to time in the mass, this is information that coming from the man who is in actually in charge of the defence industry, and who is reporting to the country’s President.  This information can therefore be considered authoritative.  

Rogozin’s report is mainly focused on civilian projects.  However he did reveal one important piece of information about a military project.

This is that Russia is developing an engine for a new ground attack aircraft to replace the SU25.  Rogozin’s precise words were that Russia has a project for “…..a military engine that we are developing for a promising new second stage attack aircraft system”.

In contrast to the talk of futuristic projects for new ultra fast interceptors and supersonic transport aircraft that have appeared in the media, his is clearly an actual programme, which so far as I know has not been discussed or confirmed previously.

Rogozin also confirmed that the VK2500 small to medium sized engine for helicopters has now entered production.    As Rogozin said, this engine is able to power the full of Russia’s medium sized helicopters, such as the KA52 and MIL28 attack helicopters and the MIL8 and KA62 transport helicopters.

Rogozin also provided Putin with a brief update of work on the PD14 - an engine based on the PS90 -  which is intended for the forthcoming MS21 passenger aircraft.

The VK2500 and PD14 engines are well known projects.  It is after his report on these projects that Rogozin’s report becomes really interesting.

It is surely not a coincidence that it is also precisely at this point that Rogozin’s language becomes vague and confusing.  This may be in part be because as a non-engineer Rogozin has difficulty explaining complex engineering projects to Putin, who also is no engineer.  It is however surely more likely that Rogozin’s vagueness is deliberate and is because Rogozin - and Putin - do not want to disclose precise details of what Russia is currently up to in the gas turbine engine field.

The gist of what Rogozin says is nonetheless clear enough and can be summed up as follows:

1. There are projects for two engine families, one an intermediate engine family to replace the Ukrainian D36, D136, AI20 and AI24 engines, and one for a big engine in effect replacing the now discontinued Ukrainian D18;

2. The intermediate engine family will be modular, with a range of engines sharing technology and design features.

3. The big engine family will draw on technology derived from the NK32 supersonic engine that powers the TU160 bomber, in part explaining why the TU160 bomber is being put back into production;

4. The intermediate engine family will provide power for the MIL26 heavy lift helicopter (replacing the Ukrainian built D136), the new heavy lift helicopter being co produced with China, and for updated versions of the Sukhoi Superjet and the MS21 passenger aircraft;

5. The big engine will power the new wide bodied long range heavy passenger aircraft being co produced with China and presumably any project for a large transport aircraft to replace the AN124;

6.  The Chinese have been consulted and have approved the big engine project and probably the intermediate engine project as well.  Since they are collaborating with the Russians on the new heavy lift helicopter and on the wide bodied  long range heavy passenger aircraft, it is likely that they are providing funding as well, though Rogozin says nothing of this;

7. Both engine families are to be capable of being adapted for shipborne use as naval warship engines.

Rogozin presents the modular approach to gas turbine engine development used for the intermediate engine family as something new.  However it was in fact used in the USSR for the Ukrainian built D36, D136 and D18 engines, all of which are closely related to each other and share technology and design features. 

Rogozin provides no details of any project for small turboprop, turbofan or turboshaft engines.  However his comment that for “civilian helicopters such as the Ansat and other promising models, we depend on the French, Canadians and Americans” suggests that work in this area is underway as well. 

A possible reason for Rogozin’s reticence is that the first batches of Russia’s new small turboprop and turboshaft engines are being used to power Russia’s new fleet of reconnaissance drones, which are known to be entering production.  As this is a top secret programme that has been accorded very high priority, Rogozin’s reticence would in that case be understandable.

Lastly Rogozin confirms that an industry level group is being set up to supervise the various engine projects.  It was almost certainly in order to announce the setting up of this group - and to publicise the fact to the industry - that the meeting between Rogozin and Putin took place and was given by the Kremlin the publicity that it was.  Given that the Chinese are providing support and probably finance, it is a fair guess that they are involved in this group as well.

There are many unanswered questions.

The intermediate range family sounds very like the various developments of the PD14, which are known to be under consideration.  Perhaps the most interesting disclosure here is that in the same way that the AN72’s D36 turbofan engine was used as the base for the MIL26’s D136 turboshaft engine, so technology from the PD14 will be used to develop a turboshaft engine for the MIL26 and the heavy lift helicopter to be co produced with China.

The nature of the big engine project is far less clear.

In 2012 the Kuznetsov Bureau - designers of the NK32 - disclosed a project for large new geared turbofan engine , called the D30, to replace the discontinued D18.  

According to the Kuznetsov Bureau, the PD30 uses “a “modified baseline gas generator” from the improved NK32 turbofan that powers the Tupolev Tu-160 strategic bomber”.  Compare this with Rogozin’s words used to describe the big engine: “we can achieve the same goal by enlarging the NK-32 engine’s gas generator”.  

Rogozin puts the upper limit of the entire range of engines under development as “35 tonnes”.  This suggests that the big engine has 35 tonnes of thrust.

Kuznetsov Bureau’s projected PD30 engine was reported in 2012 to have a power rating of just under 30 tonnes of thrust at take-off.  In its 2012 release the Kuznetsov Bureau said that should the PD30 be “selected for the Airplane 2020 program (an early version of the big wide-bodied long range passenger transport now being co-produced by Russia and China), its fuel burn could be lowered through higher bypass ratio and higher gas temperatures”.  This could suggest that the PD30’s power rating could be increased, in which case it might reach 35 tonnes, further reinforcing the suspicion that the PD30 is the big engine Rogozin is talking about.

In 2012 the Kuznetsov Bureau said that it “has issued manufacturing documentation for the PD30 and expects the engine to be mature enough for series production in four to five years.”  

Assuming that this did indeed happen then that would mean that the PD30 is roughly ready for production and testing now.  This fits in well with what is known about the timeframe of the new large passenger aircraft to be co produced with China, which makes it even more likely that the big engine Rogozin is referring to is indeed the PD30 or a closely related engine.

All this makes it sound very much as if the new proposed big engine Rogozin refers to is the Kuznetsov Bureau’s PD30 or a closely related derivative.

With a take-off thrust of just 35 tonnes the new big engine has only half the power of General Electric’s gigantic GE90.  

This means that unlike the new breed of giant airliners that are appearing in the West, the new Russian-Chinese long range heavy passenger aircraft will have to use four engines instead of two, if it is to match them in size.  More probably, it will use two engines but will be significantly smaller, though it is possible that a bigger four engined version may be built in parallel though in smaller numbers for long range international flights.  

This makes commercial as well as technological sense.  There is likely anyway to be a much bigger market for a smaller airliner than for the gigantic airliners which are appearing in the West. The new aircraft’s smaller size makes it more flexible and also more suitable for internal flights within China and Russia, which will probably be its primary focus.

In 2012 the Kuznetsov Bureau described the PD30 as “a low-risk project” because of its “extensive use of off-the-shelf components and technologies proven on other projects”.  

If so, and given that it is actually available, it is easy to see why it would be attractive for an industry that is still only in its early stages of revival.  Once the industry has become properly re-established, work can begin in earnest on bigger engines, suitable for use on bigger aircraft, comparable to the giants that are appearing in the West.

In his report to Putin Rogozin actually hints at this

“We think we should look at the issue not as a single priority goal tied to the development of particular models of aircraft, because it takes longer (from three to five years) to develop an engine than to develop a plane. We believe we need to look ahead and create a reserve for the future.”

In other words, in contrast to Soviet practice when development of a particular engine tended to be linked to the design of a particular aircraft, engine development - at least for civil aircraft - will in future mirror practice in the West, where it is engine design and development that determines the shape and size of aircraft, and not the other way round.

 

In summary, Rogozin reveals a classic Russian approach to the problems of the industry: one that is conservative, cost-conscious and methodical, drawing on what has already been achieved, rejecting schemes that are over-ambitious and futuristic, planning carefully for the future, and laying down a foundation upon which to build.  

With Chinese support there is every reason to think these projects will be brought to fruition

Though smaller than the (over large?) superliners now appearing in the West, the new Russian Chinese long range wide bodied passenger aircraft will have a massive captive market in Russia and China, whose governments will ensure their airlines buy it.  

The economies of scale - crucial in the aircraft building industry - are enormous, and will create a powerful competitor to the Western aircraft industry (Boeing and Airbus) in the not-so-distant future.

Replacement of imported Western aircraft by domestically produced aircraft will further strengthen both Russia’s and China’s already strong foreign trade position, and will significantly strengthen both countries’ domestic high-end manufacturing and machine tool industries. 

After the crisis which followed the USSR’s collapse, aircraft and engine building in Russia appears to have a bright future.

  

 

 


via Marshall Horn, CFTC The Resurrection of Russia's Aircraft Engine Industry

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