Since the early 1980s, the Sukhoi Su-25 (NATO codename of "Frogfoot") has served the close-support air strike interests of the Soviet/Russian Air Force as well as the air forces of several nations around the world (primarily Soviet-allied countries or ex-Soviet states). The type has acquitted itself quite well through a plethora of combat exercises during her lengthy operational career. At her core, the Su-25 is design comparable in battlefield role to the equally-storied Fairchild Republic A-10 Thunderbolt II ground-attack platform of the United States Air Force. Despite its decades-old origin, the Su-25 continues in a frontline operational role today (2012) and has been consistently - and adequately - modernized for the rigors and dangers of the modern battlefield. With her supporters still in place, the Su-25 should continue to bring a decade or more of faithful service for the near future as the horizon still lacks a viable replacement.
The Cold War spanned from the late 1940s into the late 1980s and covered a tension-filled portion of modern world history. The line was essentially drawn between the West - led by the United States and her European allies - and the East - headed by the Soviet Empire born from the upheaval of World War 1. The Soviet Union became a powerful military force during World War 2 thanks largely in part to Adolf Hitler's decision to invade the East, his forces finally being stalled by stretched supply lines and the Russian Winter within view of Moscow proper. The Soviet response was massive and brutal as manpower and machine were relocated through all manner of methods, eventually driving the German invaders back into Germany to which then the capital of Berlin was eventually claimed by the Soviet Army through bloody street-to-street fighting.
The events of World War 2 revealed a redesigned Europe where new nations rose and old ones fell - many guided under various spheres of influence. The differences in ideology politics between East and West would eventually come to a head and, as it was appropriately believed that, the next large-scale war would be witnessed across Europe once again, this time involving thousands of modernized tanks and armored vehicles coupled with massive artillery barrages and air support. Additionally, nuclear weapons would come into play - both on the large scale and on the smaller, portable scale.
As such, both sides began development of dedicated anti-armor measures - heavily-armored and armed tanks, anti-tank missiles, field guns and aircraft. For the latter requirement, the Americans turned to Fairchild Republic which ended up producing the excellent A-10 Thunderbolt II, a twin-engined, jet-powered aircraft armed with a massive 30mm nose-mounted Gatling gun designed specifically to defeat Soviet armor from above. Additionally, the straight-winged nature of the vehicle promoted multiple weapon stations for fitting air-to-surface, armor-defeating guided missiles, rocket pods and drop bombs. The A-10 was a very well-armed machine and extensively armored for the low-level attack role with engines mounted in individual nacelles high above the fuselage to increase survivability. First flight was on May 10th, 1972 to which introduction of the system was finally granted in March of 1977. The United States Air Force became the primary (and sole) handler of the machine.
The Soviet response was similar in scope - a largely conventional, straight-winged design to be powered by turbojet engines and capable of delivering a broad array of munitions. Design was charged to the Sukhoi concern which had already totaled decades of experience in developing viable jet-powered aircraft for the Soviet Air Force (the other well-known Soviet concern being Mikoyan). The new requirement was written for an armored, ground-attack-minded aircraft intended to support ground forces in a combined arms initiative - particularly where enemy armor was in play. Key to the design would be its field survivability and weapons delivery while all other qualities could be deemed somewhat secondary in nature (primarily speed and agility).
Development of what would become the "Su-25" could be traced back to 1968 following various design studies culminating in the T-8-0 testbed. A working prototype did not officially fly until February 22nd, 1975 when the "T-8-1" pilot vehicle was sent airborne for the first time. The aircraft was outfitted with a pair of Tumansky RD-9B turbojet engines and further review led to many inevitable revisions to the product. The T-8-2 became the second true prototype while the T-8-2D mimicked much of what became the finalized Su-25 pre-production design. T-8-3 served as a developmental model. The first Soviet Air Force group stocking the new Su-25 was made operational in 1981 to which NATO recognized the aircraft as the "Frogfoot". Production of the Su-25 began in 1978 out of Factory 31 of Tbilisi, Georgia (then under the Soviet sphere).
The Su-25 was completed with a rather basic design approach. The cockpit was set to the front-end of the fuselage in the traditional sense with a clear canopy bordered by large window framing. The sole pilot sat in an titanium-armored "tub" that offered maximum protection from ground-based small arms and cannon fire. The aircraft was given a short, pointed nose-cone assembly and a rather stunted fuselage running length. The engines were mounted along the sides of the fuselage as opposed to a side-by-side internal arrangement so as to space them well apart, decreasing the likelihood of a dual-engine flameout or power loss resulting from a direct hit. The engines were aspirated by rounded-rectangular, side-mounted intakes aft of the cockpit and exhausted through circular openings along the sides of the empennage. base The empennage itself was traditional, consisting of a single vertical tail fin, a pair of horizontal tailplanes and a short "stinger" protruding from the base of the rudder. Wings were largely straight appendages in their overall design, exhibiting sweep only along the leading edge while being left mainly straight at the trailing edge. These assemblies would be called on to support all manner of munition options across multiple underwing hardpoints. Interestingly, the Su-25 utilized a unique wing-tip-mounted airbrake system that consisted of an upper and lower panel section hinged at the front of the wing. when actuated, the panels sprung open to quickly decrease the speed of the aircraft as required. The aircraft's engines were also a unique quality of the design in that they could be fed with standard aviation fuel as well as diesel, gasoline and kerosene in extreme circumstances. As the aircraft would also be called upon to operate from rough airfields, it proved good foresight to include external maintenance equipment pods which the Su-25 could carry from base-to-base on its own. As such, maintenance could be conducted on the aircraft without a full service outfit being present. The undercarriage was made up of two single-wheeled main landing gear legs and a single-wheeled nose leg, all retractable into the design to complete the aerodynamically refined shape of the aircraft.
The Su-25 featured a standard fixed armament of 1 x 30mm GSh-30-2 internal cannon supported through 250 rounds of ammunition. The underwing and underfuselage stations amounted 11 total hardpoints for the carrying of up to 9,700lbs of external ordnance. Munition options included short-range air-to-air missiles, laser-guided bombs, rocket pods, gun pods, guided air-to-surface missiles, cluster bombs and conventional drop bombs. At least two hardpoints are plumbed for external fuel stores.
The Su-25 saw extensive combat service in the Soviet involvement of in Afghanistan where their close-support functions could be put through their paces. Operational service in the theater led to beneficial upgrades and modifications of the base Su-25 which improved the type on the whole. As the Mujahedeen began relying more on American shoulder-launched Stinger surface-to-air missiles, the Su-25 was given dedicated survival measures such as IR suppressors over the engine exhaust rings and onboard chaff/flare dispensers to help scramble ground-based radar tracking and homing missile signals. The first Su-25s arrived in the theater in May of 1981 and, in all, some 50 Su-25 aircraft would be deployed during the war. The aircraft ultimately gave a good account of themselves while surviving heavy sortie loads for several years. Lack of progress in the conflict eventually led to a Soviet withdrawal in 1989 after nine years of bloody struggle.
The Su-25 went on to find many suitors in the war-minded world. Operators beyond the Soviet Union/Russia included Angola, Armenia, Azerbaijan, Belarus, Bulgaria, Chad, Czechoslovakia/Czech Republic, Democratic Republic of the Congo, Equatorial Guinea, Ethiopia, Georgia, Gambia, Iran, Iraq, Ivory Coast, Kazakhstan, Macedonia, North Korea, Peru, Slovakia, Sudan, Turkmenistan, Ukraine and Uzbekistan.
Iran and Iraq fought one of the bloodiest wars of the 1980s through the Iran-Iraq War of 1980-1988. Iraq invaded Iran under the pretenses of upholding Islam and utilized its recently received stock of Soviet Su-25s by the end of the conflict. Several hundred sorties were handled by Iraqi Air Force aircraft in attacks against Iranian positions with one Su-25 credited lost to Iranian air defenses. Ironically, during the Persian Gulf War of 1991, at least seven Su-25s escaped coalition air strikes to Iran and were confiscated by Iranian authorities. Two additional Su-25s were lost to coalition fighters after being engaged by superior F-15 Eagles.
After the fall of the Soviet Empire in 1991, the Russian Air Force retained the services of the Su-25, particularly during the tough years following shrinking defense budgets. This proved important for the aircraft line during the Russian wars of the new decade. Chechnya had proven a thorn in the side of of Russian authorities for quite some time due to the ongoing actions of separatists and this culminated in the "First Chechen War" of 1994, a conflict that would last until 1996. Su-25s were brought to bear against seemingly outmatched Chechen forces who utilized an effective guerilla-style ground campaign in turn. While air superiority was achieved by the Russian Air Force, the war ended with a Russian withdrawal of troops in the region and Chechen separatist claimed the victory (aided by foreign fighters, primarily Mujahideen). The war had proven very unpopular on the Russian front (which dwindled overall support) while Russian military moral was at a new low (consequences of a fallen superpower). This eventually forced the Russians to call a ceasefire. At least four Su-25 aircraft were lost in the conflict.
It was only inevitable that the tensions with Chechnya would arise again and this provided the groundwork for the "Second Chechen War", another modern stage for the Su-25 aircraft. The war spanned from 1999 to 2009 and this time resulted in an undisputed Russian victory. The war was initiated after in response to the Islamic International Peacekeeping Brigade's invasion of Dagestan in the North Caucasus. Su-25s were properly outfitted and utilized in their defined low-level strike roles with success despite losing seven aircraft in the fighting. Regardless, Su-25 involvement in the second conflict was much higher than in the preceding war.
The most recent reported operational use concerning Russian Su-25s was in the 2008 South Ossetia War against Georgia. Russian military forces moved in on August 5th to support the separatist South Ossetia and Abkhazia governments. In response, Georgian forces attacked on August 7th. As both sides maintained a stable of Su-25 aircraft, the system fought for both sides in the war. The Russian Air Force made sure to destroy the Su-25 production plant at Tbilisi and eventually claimed three Georgian Air Force Su-25s while losing as many as four of its own to Georgian air defenses. Georgian Su-25s maintained a slight technological edge during the conflict, having been outfitted with modern electronics and night-capable equipment from Israel, and able to capably attack in all-weather, day-night conditions.
Like other military-minded aircraft, the Su-25 went on to see its fair share of variants produced. In keeping with traditional Soviet naming conventions, early-form versions were designated simply as "Su-25" and export-minded derivatives claimed under the designation of Su-25K (both recognized as "Frogfoot-A" to NATO). Export models were simplified Soviet forms intended to keep sensitive equipment within Soviet borders and procurement costs low for buyers. 582 Su-25 aircraft were produced from 1978 to 1989 and these were joined by 180 Su-25K models from 1984 to 1989. Upgraded mounts were born from the "Su-25SM" initiative which modernized the cockpit extensively to include multi-function displays (MFDs), a revised HUD (Head-Up Display) and broader support for newer weaponry. The Su-25SM is an ongoing modernization program (as of 2012) to which Russia expects to upgrade some 80 of its aircraft to the Su-25SM standard over the next several years in an effort to keep them viable until 2020.
The Su-25K (export) is powered by 2 x Soyuz/Tumansky R-195 turbojet engines outputting at 9,920lbs thrust each. Maximum speed at sea level is 605 miles per hour with a service ceiling of 22,960 feet. Standard armament consists of 1 x 30mm AO-17A internal gun.
It was only natural that such a specific aircraft require its own dedicated trainer variant and this arrived in the form of the "Su-25UB" (NATO "Frogfoot-B"). The Su-25UB differed from the original in that a second cockpit was added (tandem-seating) for an instructor. Cockpit controls were redundant and combat-worthiness was retained which meant that the trainer could be pressed into operational service if need-be. Twenty-five total Su-25UB trainers were manufactured. The export version of the Su-25UB became the twin-seat "Su-25UBK" (NATO "Frogfoot-B"), produced from 1986 to 1989. A more broadened two-seat attack-trainer has since emerged with the arrival of the "Su-25UBM" in 2008. This version carries modernized radar, target designation equipment and reconnaissance-minded facilities for greater tactical value over the battlefield. The permanent addition of a second pilot reduces the workload of the primary and increases situational awareness in the cockpit at the expense of internal fuel. The "Su-25BM" (R-195 engines) were developed to serve in the target-towing role and were based on the T-8BM1 prototype of 1990.
The Su-25UB development also served as a carrier-trial model for the Admiral Kuznetsov Soviet Navy aircraft carrier. Ten Su-25UTG carrier-based trainers were developed and operated from the ski-jump deck of the Admiral Kuznetsov, being appropriately outfitted with an arrestor hook and reinforced undercarriage.
The definitive "tank-busting" Frogfoot was developed as the "Su-25T" from three prototypes (the Su-25T is recognized as the "Su-39" in Sukhoi company nomenclature). The type received all-weather, day/night fighting capabilities and improved avionics as well as greater support for precision-guided weaponry. Based on the two-seat version, the Su-25T lost its second cockpit position for additional avionics and internal fuel for greater attack capability and operational range respectively. The aircraft carried its own target designator as well as an integrated laser rangefinder but apparently lacked radar. Chaff/flare dispensers were affixed to the tail stinger. The changes made the Su-25 product line a more lethal battlefield component, allowing it to operate through heavy smoke and low-light hours while accurately delivering its broad-range of ordnance. However, only eight Su-25T aircraft were ever produced and these arrived in 1990. An improved form, the "Su-25TM" now with a radar facility, was then offered to which the now-Russian Air Force accepted eight of its kind (24 intended).
The single-seat Su-25TM is powered by 2 x Tumansky R-195 turbojet engines of 9,480lbs thrust each. This provides the aircraft with a maximum speed of 590 miles per hour, a ferry range of 1,550 miles and a combat radius of 235 miles. The Su-25's operational service ceiling is reached at approximately 23,000 feet while a 11,400 feet per minute rate-of-climb can be met.
Modernization programs are expected to keep Russian Su-25s flying until 2020 though foreign-operated types will most likely be supported by respective parties much later than that. Israel offered a "Scorpion" package to its allied customers which upgraded cockpits to "all-glass" digital workspaces with an all-new HUD and twin liquid-crystal displays (LCDs) while also updating the complete navigation and weapons delivery systems.
After the break-up of the Soviet union in 1991, Georgia was one of the many nations that gained its independence from Russia. As an active operator of the Su-25 system (and former manufacturer), an indigenous upgrade program was devised and ultimately enacted in 2001. With help from the Israeli concern of Elbit Systems, the Su-25 fleet was upgrade through and through to feature an all-glass digital cockpit. The Tbilisi Aircraft Manufacturing facility reworked an operational Su-25 to serve as the flyable prototype during development and this eventually led to the new Georgian "Su-25KM" standard being realized. The Su-25KM incorporated full support for NATO-cleared ordnance, improved pilot and aircraft survivability and day-night/all-weather capability. The Su-25KM also integrated a helmet-mounted display (HMD) consistent with other modern Russian fighter aircraft as well as a robust mission and systems computer. The Georgian defense industry went on to produce a two-seat Su-25 derivative known as the Su-25U of which three examples were delivered beginning in 1996.
Sukhoi has attempted to promote alternative Su-25 offerings during the run of their well-accepted Su-25. The "Su-25R" was a failed reconnaissance-minded proposal appearing in 1978 while the "Su-25U3" would have been a three-seat training platform which proved financially unfeasible in the aftermath of the Soviet collapse.
The Ukranian Air Force, recipient of a stock of Su-25s after the fall of the Soviet Empire, have moved on to upgrade their Su-25 fleet through the "Su-25M1" (modernized attack) and "Su-25UBM1" (twin-seat attack trainer) initiatives.
Iranian Su-25s made the news in early November 2012 when they opened fire (with their internal cannons) on an American Predator UAV. The Iranians claimed the aircraft had traversed into their recognized airspace while American authorities naturally denied the incursion. The Predator UAV was not hit during the attack - the Iranian pilots seemingly unable to, or perhaps unwilling to, bring the UAV down, raising already heightened tensions between the two parties.
The Sudanese government is known to have utilize their Su-25 strike aircraft over Darfur against rebel fighters, resulting in the deaths of many civilians in the process.
All told, the Su-25 maintains a healthy and viable presence on the modern battlefield. While its history is mostly written, the system should sustain its position for the near future. The dedicated ground-attack aircraft as a whole may well-be completely replaced by the more advanced multi-role mounts coming online every few years. With the advent of ever-improved missiles and 5th Generation technology, it remains to be seen what will become of the class of aircraft that is embodied by the Su-25 and the A-10.
To date (2015), 1,024 Su-25s have been produced.