Su-25 Frogfoot

Upgraded Bulgarian Su-25 Frogfoot

Bulgarian Air Force (Bàlgarski Voenno Vàzdusni Sili) is going on with a modernization and resizing of its fleet after the long period of soviet supplies. Due to its strategical position, looking out to Black Sea and consequently to Russia and Turkey, Bulgaria had always been a theatre of interest since first World War when German empire used it as logistic base for its Zeppelin.

During second World War Bulgaria was allied of Germay and its fleet was composed by Messerschmitt Me 109E, Arado Ar 96, Dornier Do 17 and few Ju 87 Stuka and rappresent a base for Germans for the invasion of Jugoslavia and Greece and later for the invasion of Russia.

But Bulgaria saw its maximum powerful during the period of alleance with Soviet Union under the Warszaw Pact, when its fleet was composed by around 400 aircraft, such as MiG 17, MiG 19, MiG 21 in all versions, MiG 23, Su 22, Su 25 and later MiG 29 and around 100 Mi 17 and Mi 24.

After the end of Cold War, Bulgaria saw an important resizing due to the end of the Sovietic support in terms of machines and spare parts. Between 1989 and 2000 years  the Su 22, MiG 23 and a big number of MiG 21 were retired from service and many air bases were closed.

Since 2000s Bulgaria had actively tried to modernize its air fleet and many efforts had been faced with the aim of keeping in service the russian made fighter jets. In 2006 Bulgarian Governament signed a contract with Italian Alenia for the supply of three C 27J Spartan to replace the Antonov AN 24 and An 26 in the transport role.

On December 2015 the last three MiG 21 were retired definily from service, and since that time the air power of Bulgaria is rappresented by Su 25 Frogfoot in the ground attack role supported by L 39 Albatros and few MiG 29 Fulcrum in the air defence role.

Entering the NATO on 29 March 2004, Bulgaria began to partecipate to joint exercises with other NATO Countries and Graf Ignatievo air base, the biggest in Bulgaria, hosted several exercises with the partecipation of other allied fighters jests such as USAF F-15 and F-16, Italian EF 2000 Typhoon and Tornado and Serbian MiG 29.

If compared to other Countries such as Poland or Romania, Bulgarian fighters have not undergone an avionics modernization program, and therefore lack NATO standardized comunications, navigation or IFF (Identification Friend or Foe) equipment, meaning they cannot deploy abroad.

Above that, Bulgarian jets still used metric units, whereas imperial units are employed as standard within NATO. This makes it more difficult to realize the maission and whenever there are NATO Squadrons in Bulgaria for exercise, the air traffic control communicates in imperial units and this can present the MiG or Suchoi pilot with problems, because not only are they mind tuned to meters and Km/h, but they have to perform the conversion mentally. As a work-around, small conversion boards on the aircraft’s panels help them to do this more quickly.

These exercises are fundamental for Bulgarian pilots and crew to familiarize with operational procedures and standard decisions to be taken during missions , tactics and techniques, used by their collegues of NATO, with the final aim to enhance the interoperability between Bulgarian Air Force and other Forces of Atlantic Alleance and to bolster readiness to conduct combined air operations.

Su 25 Upgrade

The Su 25 Frogfoot had always rappresented the spine of Bulgarian ground attack speciality and they are based in Bezmer, in the SouthEast of the Country. It represents a simple, effective and survivable attack workhorse, purposely designed to fly multiple short-range battlefield CAS missions.

In 1980s and 1990s the Su 25 proved itself as a powerful weapon its rather dangerous job in many local conflicts. The high precision in turn allows the Su 25 to undertake non-visual bombing runs in poor weather and at night at low and medium level against fixed targets with known positions using unguided bombs from level flight.

Su-25 Frogfoot

In November 2018 the BVVS signed a USD 85.5 million contract for the major overhaul of fourteen Su 25s by the 558th Aviation Repair Plant in Baranovichi, Belarus. Unfortunately the contract was downgraded from fourteen to eight aircraft, six Su 25K single seat and two Su 25 UBK double seat and Bulgaria will decide in the next months if using the option for the further overhaul of other six machines. The recalculated cost for eight aircraft is BGN 41 million (USD 24.3 million)

Due to the strong restrictions against Belarus with regards on the supply of weapons, it took longer before the Su 25s could leave Bulgaria, transported by Iliushin Il-76 to Belarus. The first one left Bezmer air base on 28 August 2019 and arrived back to Bezmer on 21 September 2020.

Repairs were not started for a long time due to the fact that the Bulgarian authorities and banks could not decide whether the attack aircraft could be temporarily sent to the Republic of Belarus, against which the EU constantly extends the embargo on the supply of weapons and equipment that can be used for “internal repression”. Since no payments were made under the contract until the end of 2018, the amount was postponed to 2019.

As a result, in 2019, the Bulgarian parliament approved amendments to the national legislation, which allowed the Bulgarian Ministry of Defense to issue a temporary permit for the export of the Su-25s to the Republic of Belarus, where the first aircraft were sent in August 2019.

The overhaul and life extension works were required to provide the Su 25K/UBKs with eight/ten years or 800 flight hours of service life, while their overall service life is set to be extended up to 40 years, making the fleet good for use until 2028, with the potential for another 10-year service life extension, which will require another major overhaul of the airframe and engine.

The avionics upgrade includes the installation of two new radios, a new navigation system with a GPS/GLONASS satellite receiver, enhancing the informations that pilots need to accomplish their missions, an upgraded flight data recorder, a digital audio/video recorder,   a new Head Up Display, providing a field of view double that of the old electro-optical sight, and multi-functional cockpit displays used to display a digital map and flight, navigation and tactical informations.

The contract with Belarus cover even the overhaul of 16 engines R-95Sh with their life extension in other 500 flight hours. Also the weapon systems had been enhanced with the introduction of the possibility of using the 130mm S-13T rockets and even the air-to-air capability had been expanded thanks to the integration of the R-73 (AA-11) Archer highly agile short-range air-to-air missile.

The combination of the new HUD, cockpit displays, weapons computer and navigation/attack system’s digital components increased significantly the accuracy when employing unguided ordnance with visual aiming.

All the upgraded Su 25s shows a new pixel painting scheme with dark green, light green and dark brown. The upgraded jets presents the serial numbers 240, 246, 249, 252, 253 and 254 for the single seat and 002 and 095 for double seat.

The last Su-25K  was delivered to  Bezmer air base on 11st  February 2021. After completing the evaluation of the repaired and upgraded aircraft received, the Bulgarian Air Force will consider the possibility of sending six more Su-25s (4 Su-25K and 2 Su-25UBK) to Baranovichi under the available option for the upgrade.

Su-25 Frogfoot

The training of young pilots assigned to the Su 25 fleet is carried out in Bezmer air base. After the basic school on PC-9 and later on L-39, the pilots begin to fly on the Su 25UBK until achieving the certification on it, and usually it takes 30 flight hours. Then the training carries on until achieving the combat ready level, making practice in the low level flight and to the firing range where pilots usually use the cannon Gsh-30 and FAB 100 bombs.

Speaking with the mainteinance crew it emerges that the Su 25s need less assistance work then the MiG 29 and it presents chaeper mainteinance cost and this allow to have the entire fleet of the eight aircraft almost always in condition of total efficency.

All these new systems make the Bulgarian Su 25 more combat ready and more effective in providing Close Air Support , isolating the combat area and assisting the engagement of land Forces and naval assets and it will continue to perform the Bulgarian capability of ground attack for many years to come.

Su-25 Frogfoot

A big thanks to Col. Milen Dimitrov Base Commander, Lt. Col. Kaloyan Milkov deputy Base Commander, Maj. Radostin Lyutskanchev, Maj. Petkov (Bulgarian Air Force Spokesman) and Lt. Vladimir Ikonomov.

Article and images by: Andrea Avian