Sukhoi Su-25TM (Su-39) Aircraft: Specifications, Design Features

Sukhoi Su-25TM (Su-39) Aircraft – Superior skies are one of the most important aspects of modern military operations. Control of the airspace allows striking the enemy’s position and disabling not only critical objects but also armored vehicles. The Stormtrooper is designed for just this purpose.

Sukhoi Su-25TM (Su-39) Aircraft: Specifications, Design Features, and Advantages

MilitaryEzyInfo.com – This combat aircraft is designed to address a variety of missions – from conducting air combat to defeating ground targets. The primary emphasis is on supporting ground and naval forces in large-scale and localized conflicts.

Sukhoi Su-25TM (Su-39) Aircraft: History

The development of the Su 39 Thunderbird was closely related to the modernization efforts of the Su-25. This attack aircraft has been designed since the mid-1970s and began active use in 1981. They passed combat tests in Afghanistan and demonstrated the need for attack aircraft in local conflicts.

Gradually, the aircraft attack aircraft were upgraded and more requirements were placed on new developments.

In response to these requirements, the Su-25T was improved, with an emphasis on counter-attack tanks. Later, it became the basis for an upgraded version of the Su-25TM, acquiring the Su-39’s specifications. Work on this upgrade began in 1986, and the first prototype flight took place in 1991.

Initially, production of the new attack aircraft was scheduled to start at the Tbilisi Aviation Plant. However, the collapse of the Soviet Union made it impossible to implement the project. Production was transferred to Ulan-Ude. The first pre-production Su-25TM flew in 1995. At the same time, it was given the Su-39 index.

Sukhoi Su-25TM (Su-39) Aircraft: Design Features

The overall design of the Su-39 repeats the design of the Su-25UB combat trainer. The key difference is the addition of a fuel tank and electronics on the co-pilot. The twin-barrel gun unit has been moved 273 mm to the right, taking into account the location of the additional avionics equipment. The front support of the chassis has been moved 222 mm to the left.

Fuselage

The nose section of the fuselage received a lengthened and enlarged form to accommodate the “whirlwind” system. The shape of the nose fairing is also different for the laser target designation system. The center of the fuselage follows the design of the Su-25UB with the addition of a fuel tank at the rear.

Reservations

The order for the attack aircraft was borrowed from the original Su-25. The pilot was housed in an all-welded cockpit made of the aircraft’s titanium armor. Its thickness is as follows.

Side thickness is: 24 mm.
Rear wall and bottom: 10 mm.
Front wall: 24 mm.
Frontal armor block: 57 mm.

In some cases, the armored cockpit can withstand the impact of 30 mm shells. This ensures the high survivability of the crew.

Opera

One of the essential differences between the new attack aircraft and the basic model is the presence of horizontal wing boosters in the longitudinal tunnel. The wings of the new attack aircraft are unified with those of the Su-25UB, but the container of the brake shield receives the antenna of the Irish system.

Power Plant

The Su-39 is fitted with two P-195 turbojet engines. Compared to the original Su-25 powerplant, it increased the production life and thrust in emergency mode, reduced fuel consumption and infrared radiation. The TTH of the engines has the following indicators.

Fuel: kerosene, gasoline, diesel.
Engine length: 7.88 m.
Diameter: 0.805 m.
Basic weight: 574 kg.

Cockpit

The cockpit is sealed and placed in an armored compartment. The overpressure is 0.25 kg per square centimeter, which raises the threshold to 10,000 meters. The pressure is automatically maintained by a control unit and an outlet valve. The cabin lights consist of a fixed sun visor with a transparent armor block and a folding section with an armored headrest.

Aircraft Stabilizer

The Stormtrooper Stabilizer is designed for three positions: flight, maneuver, and landing. Switching is done by hydraulic cylinders.

Chassis and Frame

The chassis of the Su-39 is a triple kit, the prop is unified with the Su-25 and Su-25UB. In-flight, the landing gear is removed and the niches are closed by kinematically driven curtains. The landing gear is released and cleaned by two hydraulic systems.

Radio Electronics

The radio electronics of the Su-39 attack aircraft are represented by the Spear-25 radar system, which has the following features:

Slot antenna, diameter: 0.5 meters.
Scan angle by altitude: +25°/-55°, azimuth: ±40°.
Field of view: ±10°/±20°/±40°.
Number of simultaneously accompanied targets: 8.
Number of targets attacked simultaneously: 2.

The effective scattered area (ESR) of the airborne target in free space is 5 m2 with a detection range of 57 km for reaction and 30 km for inhalation. The second indicator to the ground has been reduced to 20 km.

The “Dagger” radar system has been corrected for the guidance of anti-tank guided missiles. The aircraft also has a set of “Iltish” air defense systems, including:

Irradiation detection and identification system.
Gardenia active radio jamming station.
A container containing an infrared trap and dipole reflector.
Sukhogruz, active infrared jamming generator.
Route selection system for maintaining radar cover “Omul”.

All the systems used are combined into a common targeting and navigation system “Orbita-20”. It makes possible the detection and conduct of small-scale ground targets for which all aircraft weapons are automatically assigned targets. The system also includes the “Squall” targeting system.

The Targeting System “Shkval”

The photoelectric system “Squall” has the following features:

Wide and narrow viewing angles of the daytime equipment – 2.7×3.6° and 0.73×0.97°, respectively.
Wide and narrow night viewing angles – 18.2 × 13.7° and 7.3 × 5.5°.
Height and azimuth – +15°/-80° and ±35°.

Depending on the altitude, the system allows you to view terrain strips from 500 to 2000 meters. At 15 km found a detached house, tank – 8-10 km. The target is kept in escort, regardless of the maneuver performed. Automatic ranging allows not only the target designation of guided missiles but also improves the accuracy of unguided munitions, including free-fall bombs.

In conjunction with the “Squall” system, the use of the laser rangefinder “Quay.” The Mercury system is used at night and can be supplemented with a small nighttime thermal imaging system known as the “Hod”. The latter is combined with the “Dagger” complex.

Sukhoi Su-25TM (Su-39) Aircraft: Battlefield

The Su-39 combat weapon is represented by the following complexes:

One 30mm Gsh-30-02 gun with 200 rounds of ammunition.
Two each of R-60 and R-73 air-to-air missiles (or R-27R/T, or R-77).
Air-to-surface guided missiles: 16 supersonic anti-tank “Vortex” or 4 X-25 and 2 X-29L/T (or X-58, or X-31, or X-35) or 8 C-25L.
Unguided rockets: 160 80 mm C-8 or 40 122 mm C-13 or 8 240 mm C-24 (or 266 mm C-25).

In addition to the missiles, the attackers were equipped with free-fall and modified bombs. This weapon is represented by eight half-ton FAB-500s, RBK-500s, or the equivalent of 250 kilograms. Other ammunition can also be used as an alternative.

The gun cases are also in service on attack aircraft. The weapon is represented by four SSPU-22-1s, equipped with a Gsh-23 twin-barrel gun (23mm caliber) that can fire 260 rounds. Another option was four SPSU-687s with a 30mm GSh-301 cannon and 150 rounds of ammunition.

The weapons differ due to the experimental nature of the development and the multi-mission capability of the attack aircraft. The aircraft were equipped differently depending on the set target. Due to the lack of serial production and certain standardization, the issue of the armament of the Su-39 remains unresolved. Basically, the systems available for the aircraft are described.

Sukhoi Su-25TM (Su-39) Aircraft: Full Specifications

The Su-39 specifications are based on four pre-production aircraft and the Su-25T upgrade program. Accordingly, the flight and technical performance of the attack aircraft is presented, based on the tests conducted and the results obtained.

Size, Weight, Length

In terms of dimensions, Su-39 has the following indicators:

Overall length: 15.33 meters.
Wingspan: 14.36 m.
Height: 5.2 meters.
Wing area: 30.1 m2.
Scanning angle: 20°.
Base: 3.58 m.
Chassis Rail: 2.5 m

Flight Speed

The flight characteristics of the attack aircraft are expressed in terms of the following values.
– At full load, the aircraft’s flight speed is 950 km/h.
– Landing speed: 240 km / hr.
– The runway lengths of the concrete and dirt runways are 550 and 600 meters, respectively.

The permissible actual altitude of flight is 10,000 meters. In combat use, the altitude of the attack aircraft can reach 30 meters to 7 km. At the permissible altitude, the range of combat flight is 900 kilometers and the range of ground flight is 400 kilometers. These values are increased to 1250 and 750 km if the overhead fuel tank (PTB-800) is used. The range of the ferry with 4 additional tanks (2×1150 and 2×800 liters) is 2500 km.

Fuel consumption

Compared to the Su-25, fuel consumption is reduced to 0.89 kg/kgf/hr with the new engine. In comparison, the fuel consumption of the base model is 1.28 kg/kgf. The Su-39’s gas consumption is 66 kg/sec.

Sukhoi Su-25TM (Su-39) Aircraft: Combat

The Su-39 was not adopted into service, nor was it put into serial production, so it was not used in operational conditions. The relevance of the development and the TTX presented by the aircraft is based on the application experience of the Su-25. Since the war in Afghanistan, these attack aircraft have been involved in many conflicts in Europe and Asia. It is well documented that these weapons have been used in eastern Ukraine and Syria.

The development of the Su-39 focused on improving the anti-tank performance of the Su-25T variant. The new attack aircraft had to deal with enemy combat equipment, including the destruction of ships. This capability makes the aircraft a support tool for ground and surface combat.

The overhead container with the Spear-25 radar system extends the capabilities of the attack aircraft, allowing it to engage in full-scale air combat with enemy fighters. So the new aircraft were equipped with air-to-air missiles.

Sukhoi Su-25TM (Su-39) Aircraft: Advantages and Disadvantages

Considering the known technical characteristics, the Su-39 stands out among its advantages:

Improved flight performance and lower fuel consumption.
Increased pilot protection in the armored cockpit.
The survivability of the aircraft itself has taken steps to prevent the fire from entering the fuel tanks.
Improved avionics, with emphasis on modern systems and electronic means of countering the enemy.
Various weapons for air combat and surface targets.
Many components and structures are unified with those of the Su-25UB, which is currently in production.

The cost of assembly and maintenance has become a major issue for the new attack aircraft. After the collapse of the Soviet Union, the lack of funding prevented the aircraft from going into series production and the modification of the existing Su-25T.

From a technical point of view, the shortcomings of the Su-39 are difficult to describe. Pre-production prototypes were tested and certain shortcomings were found. However, such problems are found in any development and are eliminated as early as possible in the mass production process. Since the Su-39 has not been used on a large scale, its strengths and weaknesses remain theoretical indicators.