There were two aircraft of the Sukhoi Attack Aircraft Concern (Sturmoviki Sukhogo in Russian) shown at a static display during the MAKS 2001 air show. The Su-39 (Su-25TM) has been repeatedly displayed around earlier and is known to the public well enough, while the Su-25SM upgraded by the Air Force’s 121st aircraft repair plant at Kubinka was shown for the first time. The Su-25 upgrade is aimed at expanding their combat capabilities, enhancing lethality and slashing operating and maintenance burden. The plane’s navigational accuracy is to grow by an order of magnitude while its ordnance’s efficiency is to hike by two to three times.
Along with repair, the upgrading of the aircraft included a wide range of improvements through the installation of advanced avionics:
– creating a new cockpit-management system with a color multi-purpose display;
– fitting the PrNK-25SM sight/navigation system with a satellite navigation capability, which is compatible with the GLONASS (Russia) and NAVSTAR (USA), and MF OES Zakhvat multipurpose optoelectronic system;
– replacing the T8-54 weapons management system with the SUO-39;
– fitting a new aircraft transponder.
Among other modifications are the new Banker-2 radio and ARK-M automatic radiocompass, MSPU voice information equipment and a data preparation panel, a new backup gyrohorizon, an airborne video monitoring system and SVR-25 information registering unit, SOK-UBD built-in test system, UBR-P universal airborne registering unit, PGL-40-2SM AC generator. The KS-1 anti-surge system is replaced by a more up-to-date ESVS one.
The upgrade increases combat payload on the new MBD3-U2T-1 bomb racks up to 5,000 kg and expands their ordnance list allowing R-73E air-to-air guided missiles and S-13T rockets with blast fragmentation and armour-piercing warheads, etc. The new modes of regular ordnance employment enable the aircraft to fire Kh-25ML and Kh-29L missiles in horizontal flight, carry out navigational bombing both day and night time in all weather conditions, and engage two air targets during one attack.
An electronic intelligence station, the successor to the obsolete radar warning system, that detects emitting air defence radars and warns the pilot of the threat degree considerably reduces a possibility of hitting the modernised aircraft.
Vladimir Babak, the president of the Sukhoi Attack Aircraft scientific and production concern was kind enough to grant this interview to our magazine.
– The skinny has it that Sukhoi Attack Aircraft worked on the modernisation of the Su-25 ground attack aircraft for quite a long time but it is only this year that we have seen the upgraded aircraft. How did the idea of modernisation originate?
– This idea was suggested three or four years ago. The Air Force voiced a wish for an upgraded Su-25, and it literally took me one night and two sheets of paper to write down “an image of the upgraded aircraft”, which were the initial data for the modernisation of the Su-25. That was based on the aircraft combat employment experience, on our research and production experience. However, the original proposals were somewhat wider than those demonstrated at the exhibition. We believed, the aircraft needed a built-in radar, which was suggested to the Air Force. It was based on all those requirements that we set today, too. But then the military was not ready for addressing this question. Yet a year and a half ago the Air Force decided for the upgrade of the Su-25, but without fitting the radar. Today we have a decision signed for the modernization of three Su-25 aircraft this year.
– Why the Air Force’s 121st aircraft repair plant at Kubinka was chosen to be a production base?
– It is a more rational decision than teaming with a commercial plant. Besides, it cuts down expenses and allows repairing aircraft along with its upgrading. To be more correct, modernization and repair are done at the same time. According to my estimate the 121st aircraft repair plant is capable of upgrading fifteen to twenty aircraft a year. That is quite enough.
We had disagreement on this issue with the production plant in Tbilisi (Tbilisi Aerospace Manufacturing, TAM). On the one hand Vazha Tordia, Director General of the TAM is ready to cooperate with Russia, on the other hand he focuses on the upgrade variant that was exhibited this year in Paris. We have made several attempts to set the modernization of the Su-25 at the TAM going, we have had meetings and discussions but failed to move beyond that point.
As early as the time that we started working on the first upgrade variant that included the radar, we gathered a representative meeting attended by the chief air forces’ engineers of the Air Forces from Ukraine, Belorussia and other CIS countries. Prior to that we had calculated that it would be more cost-effective to modernize the Su-25 at one plant both from the production preparation point of view, personnel involved and financial reasons. But Ukraine wanted to go it alone, the same with Belorussia. We suggested that tests be carried out together, which is also quite expensive. They are still thinking.
Actually, we have only assembled the aircraft and demonstrated it at the MAKS 2001 air show. Now we have to work everything through and get ready for the tests. Currently, we have removed all the equipment and handed it over to the St.Petersburg-based Elektroavtomatika design bureau for all the algorithms to be tested on the test-beds. As all algorithms and interrelations are tested and the aircraft finalised, we will start flight tests. I believe the modernised aircraft will make its first flight in late November.
What was changed in the modernised aircraft? Will it be easier for the pilot to handle it?
On the one hand, it will be easier, on the other hand – more difficult. It is going to be easier because we excluded many extra operations. On the other hand, we introduced new equipment, a new sight system, new displays. It all has to be mastered. But basically easier, of course. I have identified for myself that the simple Su-25 is somewhat the same as the first grade of school, the Su-25SM – eighth – ninth grade, when Su-39 – is a graduation year of the college. The sight system changed its computer and indication. The previous ASP-17 sight was built 25 years ago. Now it is a completely digital system. Elektroavtomatika developed a very good computer-reliable, with high processing speed. But increased accuracy of combat employment requires more than a computer; it needs more accurate initial information. That is why we had to change all sensors: angle of attack ones, inertial system, air signals system, Doppler radar sensor. We hope these measures will dramatically increase accuracy of horizontal flight bombing, while the precision of navigation should be increased iteratively.
The most important is that it will allow more accurate bombing as 90-95 per cent of combat tasks are accomplished using non-guided weapons. Laser- or TV-guided missiles require certain skills from the pilot and if he has not been properly trained then accuracy is out of question.
Have you made provisions for a twin-seater which will enable pilots to undergo required training?
Out of the three aircraft that we plan to modernize by the end of this year one is a twin-seater. Its upgrade pattern is identical to the single-seat aircraft. Frankly speaking I would like the twinseater to be upgraded to the variant with the radar. Or with the Shkval – in other words to get back to the variant that we started with when we made the first Su-25UB at the aircraft plant in Ulan-Ude. At that time we wanted to commonise its nose part with the Su-39 to be able to fit Shkval on the twinseaters. That is why we are going to have a kind of split variant. The Su-25UB coming from the Air Force will be upgraded to the basic variant, while the aircraft that will be built from scratch – to the other one. But it still has to be given a thought.
Can the Su-25SM be compared with the Scorpion?
We see the Scorpion as an aircraft one class below. Their upgrade doesn’t cover even a half of what we have done. They did not replace the sensors, which will affect bombing accuracy. However, they gained from another point having made provisions for TV-guided weapons. We have not done that yet.
How long the Su-25 family aircraft may remain in service?
Quite a long time. The aircraft turned out to be a very harmonious one. The aircraft’s airframe was designed according to the pattern, which is ideal for an aircraft from the viewpoint of combat employment. Separately located engines, a strong cockpit, a straight wing, a debugged control system. It is a simple and reliable aircraft capable of accomplishing almost any mission. From the airframe point of view and with the current state of affairs, it may fly another hundred years if we assume 20 flying hours a year. Of course the equipment requires more frequent replacement. Besides, I don’t think the Su-25SM is the last upgrade. As a platform the aircraft may be used for at least thirty years.
It turns out that the Air Force will not need a new attack aircraft for another three decades. What is in store for the Su-39 then?
If we take the tasks that we face today, there is the need for the Su-25TM (Su-39). Our Customer, our Air Force are quite interested in this system. There are some tasks that are too tough for the Su-25. The Su-25TM is capable of landing a regular bomb with the bull’s eye accuracy wherever it is required. It fights armoured vehicles and carries out its tasks at night and in bad weather conditions. The Su-25TM packs missiles that not only stop the modern tank but literally tear it apart. It makes a good psychological effect. The Su-25TM pilots say they just enjoy performing missions.
Probably, the regiments must be equipped with aircraft of all types – ordinary the Su-25, Su-25SM and Su-25TM (Su-39). Each of them will be found use for.
Andrei YURGENSON
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June 22, 2002 at 6:22 am