Russian Civil Aviation: News #5

flamming_python wrote:If Putin is talking about how Baikal aircraft development has to be sped up, then it clearly is a priority project

And the need for a new model with all-Russian components, including the engine, was obvious already back in 2014

They wasted a lot of time with all these redesigns and modernizations that rely on the same Western powerplants

Those Redesigns and modernisations of An-2 were not wrong.

Some of them were also technological demonstrators (especially the composite versions, and the same company (SibNIA) also did an twin engine version with composite wings of the Yak-40, unfortunately again with foreign Garrett/Honeywell engines, the TFE731 turbofan (about 1,5 to 2 tons of thrust each (at max takeoff)).

What I do not understand is why there were so many versions relying on the old Garret (now Honeywell) TPE-331 engine since the An-3 was certified on an turboprop engine produced in Omsk.

From Wikipedia page concerning An-3

The first prototype flew as early as May 13, 1980, but because of a lack of official interest in the project, work proceeded very slowly. Flight testing was not complete until 1991. It is one of the few turbine-powered biplane designs to date. The An-3T received its Type Certificate on 31 August 2000. Supplements to the Type Certificate included version with ski landing gear and an agricultural version

The An-3 has been produced at the Production Corporation Polyot in Omsk between 2000 and 2009.

By the way, does anyone know if the Polyot company is still involved in aircraft production?

In 2009 they were indicated as possible production site for the An-70, but since then I believe they "only" produced satellites, space launch vehicles and parts of the Angara rockets.

Its engine was the TVD-20 turboprop (Takeoff power  1375 hp) designed and produced (for the An-3 and for the An-38) by the Omsk Engine Design Bureau (which is currently a subsidiary of NPO Saturn.

https://web.archive.org/web/20181024085451/http://omkb.ru/

The engine is of an "inverted" design (in the front part of the power plant behind the reduction gear with the tractor propeller there is a turbine with an exhaust device, and the compressor with the inlet device is located in the rear part of the power plant) of a modular design, consisting of modules:

- Gas generator (8-stage axial-centrifugal compressor, combustion chamber with a rotating nozzle, 2-stage axial turbine);

- Free turbine (2-stage axial);

- Reduction gear (2-stage, one stage planetary);

- Aircraft accessory box;

- Gas generator accessory box;

- Starter box (starter-generator);

- Exhaust pipe.

Power is transmitted to the propeller shaft through a reduction gear located behind the free turbine and connected to it by a spring.

lancelot wrote:I will believe in those deadlines once they have a working VK-800 engine certified and in serial production.

The main issue is that unfortunately Klimov abandoned the development of that engine in 2007 and then it was restarted only many years later by a new team (formerly employees of Pratt and Whitney Russia), in the newly established engine design division (based in Sankt Petersburg) of the Ural civil aviation plant.

I believe that originally that engine was planned for a Russification of the Let L-410 turboprop aircraft, since the Czech firm which produced the original engine had been bought by the American GE.
The good point is that being in Sankt Petersburg, possibly they can cooperate with Klimov easily.

https://aviation21.ru/dvigatel-vk-800sm-stanovitsya-klyuchevym-dlya-turbovintovyx-regionalnyx-samolyotov/

The VK-800SM engine is becoming a key engine for regional turboprop aircraft
25.05.2024

The history of the VK-800SM turboprop engine originates from the VK-800V helicopter engine project developed by the St. Petersburg enterprise FSUE "V. Ya. Klimov Plant". The power plant was supposed to replace the turboshaft enginePW-207K, which Ansat helicopters were equipped with until 2022.

During the period from 2003 to 2007, a full set of documentation was developed at Klimov for the VK-800V, a draft design was released, and a prototype engine was manufactured and successfully passed bench tests.

Since 2008, work on the power plant has been carried out on an initiative basis at the expense of the enterprise's own funds. It can be said that over the next ten years, the development of the engine was practically curtailed, and it was decided to adapt the VK-650 for the Ansat . In fact,working on a new version– VK-800SM for the LMS-901 Baikal aircraft began at the turn of 2018-2019.

The decision to implement the VK-800S project was made in the spring of 2018. UZGA worked on the engine for the LMS-901 together with the Scientific and Production Center "Blades. Compressors. Turbines" LLC. On the part of UZGA, the VK-800SM (modernized VK-800S) was developed by specialists from its St. Petersburg engine division, the backbone of which was the former team of the Pratt & Whitney Russia (PWRus) branch, closed in 2014 by overseas sanctioners. Having analyzed the design documentation for the VK-800S, the design engineers came to the conclusion that the engine for the Baikal aircraft required a complete redesign, which was done in the shortest possible time.

In September 2019, CIAM approved the preliminary design for the use of the VK-800SM engine as an aircraft power plant with a recommendation to develop both twin-engine and single-engine versions of the LMS-901. In the same month, the technical documentation for the VK-800SM engine for adaptation to the Baikal was transferred to UZGA.

The VK-800SM is designed according to a scheme traditional for engines of this size: a compressor with one highly loaded, highly efficient centrifugal stage and a single-stage turbine. The free turbine is made two-stage.

As the magazine “Wings of the Motherland” writes (pdf, p. 73), a distinctive feature is the use of a film-cooled combustion chamber in the VK-800SM design, which reduces the consumption of cooling air and significantly increases the efficiency of the engine. Modern technologies for casting turbine blades using heat-resistant alloys will contribute to improving the resource characteristics. The closest attention is paid to the reliability of the engine, given its use as part of the power plant of the single-engine LMS-901 "Baikal".

At the end of 2022, UZGA delivered the first prototype of the VK-800SM to the CIAM stand. From January 15 to March 17, 2023, as part of the experimental design work, the autonomous installation of the engine combustion chamber successfully passed bench tests. The tests were conducted to confirm the calculated parameters of the combustion chamber operation and check its ignition in the entire range of operating altitudes. The results obtained during the tests showed a significant excess of the launch altitude relative to the technical specifications. Reliable ignition of the combustion chamber at altitudes of up to 8,000 m was confirmed. During the tests of the gas generator on the stand, UZGA and CIAM specialists performed more than 100 starts with ignition checks from one spark plug and reduced network voltage. All of them were successful.

The VK-800SM was planned to be transferred for flight tests as part of the Yak-40LL flying laboratory to SibNIA at the end of 2023. The first flight of the Baikal aircraft with the new engine is scheduled for the third quarter of 2024, and the completion of the VK-800SM certification is scheduled for the end of this year. However, there have been no reports of the start of flight tests from either Novosibirsk or Yekaterinburg, which may indicate that the certification dates for both the engine and the Baikal aircraft will be shifted, as will the start of serial production of the aircraft.

In addition to the LMS-901 Baikal, the VK-800SM engine is expected to be used in the joint Russian-Belarusian aircraft LMS-192 Osvey and the UTS-800 training aircraft , which makes this power plant key for the further development of both small aircraft for regional air transportation and for a promising training aircraft.

Andrey Velichko
for the website "Aviation of Russia"

Here it mentions also the VK-650, but work on the VK-650 officially started something like 10 years after VK-800 development had been frozen.

Most probably development of the VK-800 had been paused to favour the MS-500V from Motor sich as a potential engine for Ka--226 and Kazan Ansat.

Only after cooperation with Ukrainian firms was impossible they restarted to think at a local engine, and then they decided to go for a brand new turboshaft engine for small helicopters exactly for that power range (while the VK-800 would have needed to be either modified a lot or de-rated with performance impact in order to be used in the ka-226 or Kazan Ansat (580 to 630 hp).

Of course they could also have done a turboprop (aircraft engine) version of the VK-650 but it would be underpowered for the target aircraft and a more powerful derivative would have needed additional modification and work, quite redundant since a lot of preliminary work had been done already on the VK-800.
The VK-800 is instead a perfect alternative to the Czech Walter M601 of the let-410, currently called GE Hseries engines (H75, H80 and H85 rated from 795 to 898 hp).

In paper the VK-800SM is better than the GE engine in every aspect (except that the the foreign engine is already certified and in serial production).

There is nothing wrong with its current development, only that unfortunately they lost more than 10 years because they favoured a Ukrainian firm at that time.

And it could have been worst, I remember having read articles from before 2013 were it was mentioned that the design and make work for the combustion chamber of the PD-14 could have been assigned to Motor Sich.

Possibly next step would be a turboprop derivative of the VK-1600V turboshaft (max takeoff rating 1400 hp), or possibly a brand new engine in the power range between the VK-800 and the VK-1600 (so something optimised for 1000/1200 hp at max takeoff).

This could be either a scaled up VK-650 or VK-800 design (1-1-1 scheme (1 stage centrifugal compressor, 1 stage axial HP turbine, 1 stage axial free turbine (which in a turboprop is the one connected to the propeller shaft), or a scaled down VK-1600 design (2-2-2 scheme, 2 stages centrifugal compressor, 2 stage axial hp turbine, 2 stage axial Free turbine (LP turbine connected to the propeller shaft for a turboprop).

Actually in the past Russia had an engine more or less in this power range, made in Omsk (and later also produced in Poland), but which had a more complicated structure (combined axial/ centrifugal compressor)
TVD-10, has a six-stage axial compressor and a single-stage radial compressor , which is driven by a two-stage turbine . The drive turbine of the working shaft is designed as a single stage. The engine has a length of 1.88 m and a weight of 141 kg.
They had done also a larger derivative (TVD-20) in the power range of the VK-1600 (1400/1500 hp) and which was also used for the An-3 (and An-38, in addition to the foreign engine).

While they wait for a new Klimov engine in that power range (which is currently not the priority), I do not understand while they try to reverse engineer the Honeywell TPE-331 instead or putting back in production the Omsk TVD-10 and TVD-20 turboprops.

At least in the light aircraft market there are some aircrafts that are in service and could still be in production in Russia (in Novosibirsk) (modernised An-2/TVS-2MS and An-38, but suffer from the lack of a local engine in production.