On this day in aviation history, February 8, 1967, the Saab 37 Viggen made its first flight. Designed as a multirole fighter and attack aircraft by the Swedish Aeroplane Corporation (SAAB), the Viggen was one of the most capable aircraft of the Cold War to be developed by a neutral power. Although it would never fire a shot in anger, Viggen would gain the admiration of its pilots and the respect of both NATO and Warsaw Pact pilots and remains a favorite of many aviation enthusiasts around the world today.
Throughout the 20th century, the Kingdom of Sweden was well-known for its neutral stance during both the First and Second World Wars, even as neighboring countries went to war and occupied each other’s territory in close proximity to Sweden. Yet Sweden also realized that in order to maintain its neutrality and defend its sovereignty, it would have to rely on own its own industry to provide for its own defense. As such, the Swedish Aeroplane Corporation (Svenska Aeroplan Aktiebolaget; SAAB), which was established in 1937, had begun developing fighters and bombers for the Swedish Air Force.
By the early 1950s, Saab had produced Sweden’s most advanced fighter up that point, the Saab 32 Lansen (‘Lance’) and was set to fly the first supersonic interceptor developed in Sweden, the Saab 35 Draken (‘Kite’/’Dragon’). But with every new aircraft comes the proposal to eventually construct a replacement, and even before the Draken made its first flight, preliminary studies began to consider finding its successor.
Saab tested over 100 different concepts to meet the Swedish Air Force’s design specifications, with Finnish aircraft designer Aarne Lakomaa being among the engineers proposing and scraping these concepts as they ran into insurmountable issues before the Swedish Ministry of Defense ordered any new design into production. One of the most challenging aspects of the design of the Saab 37 was the fact that the aircraft was expected to be at speeds of Mach 2 at high altitude and Mach 1 at low level, integrate with the country’s air defense network, and have the ability to operate from runways as short as 800 meters (2,624 feet) in length, or even civilian roadways impressed into military service in the event of all-out war. The aircraft also had to be easy to maintain and rearm by conscript servicemen drafted for temporary service.
It would be a tall order for any company to achieve, but fortunately, SAAB received so help from the United States. In 1960, the U.S. National Security Council approved defense assistance to Sweden in the event of war with the Soviet Union. As part of this agreement, the U.S. gave Sweden access to its latest aerospace technology, which enabled SAAB to cut development time and costs significantly. In December 1961, the Swedish government approved the development of Aircraft System 37, which would become the Saab 37 Viggen. When the design was finalized in 1963, it featured a double delta wing canard layout. The foreplane on the aircraft was mounted ahead and above the main wing in order to provide extra lift at slower speeds and improve its short takeoff and landing (STOL) capabilities.
Originally, SAAB had intended to use a British engine under development, the Rolls Royce Medway. However, the Medway was cancelled while in its prototype stage, and SAAB found a new engine in the Pratt & Whitney JT8D, which was then manufactured under license by Volvo as the Volvo RM8. To improve performance, the engine was fitted with afterburners built in Sweden and a thrust reverser that further added its STOL capabilities in landing on short runways or even motor highways in military exercises.
With an engine secured, Saab began work on six prototypes for the Saab 37 Viggen, with the first of them being rolled out to the Swedish press on November 24, 1966. Three months later, on February 8, 1967, Saab’s chief test pilot, Erik Dahlstrom, took the prototype for its first flight, and the aircraft’s excellent performance. In April 1968, the first variant of the Viggen would be the AJ 37, which was a ground attack aircraft that could fulfill the secondary role of being a fighter. After being shown to the world outside Sweden at the 1969 Paris Air Show in France, the first production model made its first flight on February 23, 1971, and in July of that year, the Viggen entered service with the Swedish Air Force.
The name Viggen is actually somewhat complicated. It is derived from the Swedish word vigg, which has two meanings. The first refers to the tufted duck, while the vigg is also associated with the term åskvigg, or “thunderbolt”, which are associated in Norse mythology as originating from the hammer known as Mjölnir wielded by the god of thunder, Thor. The first definition also serves as a reference to the aircraft’s canard wing configuration, since “canard” is French for duck. The Viggen’s manufacturer Saab AB has stated that both references are valid for their aircraft.
Even considering both the latest American and Soviet jet aircraft of the time, the Saab 37 Viggen was among the most advanced combat aircraft in the world. In addition to its powerful RM8 engine, the Viggen’s avionics package was one of the most advanced designs of its day. In its nose was the Centralkalkylator 37 (central calculator 37: Ck 37), the world’s first airborne computer to use integrated circuits, which was later replaced by the CD 107, a licensed development of the Singer-Kearfott SKC-2037 digital central processor. The Viggen also flew with a heads-up display (HUD) system for its pilots and was fitted with mechanical and digital systems that meant that a second crewmember was not required.
A total of five developments of the Viggen were created and flown for the Swedish Air Force. The first was the aforementioned AJ 37, which served as a single seat multirole strike fighter primarily dedicated to ground attack but capable of air-to-air engagements as well (modernized models were designated as AJS 37s). Then there was the SK 37 two-seat trainer with no radome and limited fuel capacity over the combat aircraft, the SF 37 photo-reconnaissance single seater, the SH 37 maritime patrol/anti-shipping aircraft, and finally, the JA 37 single-seat, all-weather interceptor, with the secondary role of ground attack was introduced into service in 1980, with a Garrett AiResearch digital Central Air Data Computer (CADC) modified from the one used on the Grumman F-14 Tomcat. Between the five variants, a total of 329 airframes were produced.
In operational service, Saab Viggens operated from airbases across Sweden, and in addition to participating in joint exercises between the separate branches of the Swedish military, they patrolled the Swedish Baltic coast to alert their superiors to any violations of Swedish airspace or territorial waters, be they Soviet or American. While the Viggen was in service, the United States Air Force deployed the Lockheed SR-71 Blackbird Mach 3 reconnaissance aircraft from bases in the United Kingdom, flying in a small pocket of international airspace over the Baltic Sea to conduct reconnaissance on Soviet and communist Polish military installations in a loop unofficially nicknamed the “Baltic Express”. Given the confinements that the SR-71 crews had to work with, the Viggen pilots caught on to the predictable flight paths of the Blackbirds, especially on the return legs of their journeys. Despite the best efforts of the Blackbird’s Electronic Counter Measures (ECM) system, the Viggen became the only aircraft acknowledged to get a radar lock on the SR-71, using target information from both the Viggen’s onboard fire-control computer and ground-based radar in the international airspace between Öland and Gotland.
But just as the Viggens could secure a radar lock-on to the Blackbirds, there was at least one instance in which the Viggen served as the Blackbird’s protector. On June 29, 1987, SR-71A 61-7964, flown by Lt. Cols. Tom Veltri (reconnaissance systems officer (RSO)) and Duane Noll (pilot), was on a reconnaissance mission over the Baltic when its right engine exploded, causing it to lose altitude and enter Swedish airspace. A pair of unarmed Viggens on a training mission, flown by Majs. Krister Sjöberg and Roger Möller, were vectored by ground controllers to the Blackbird’s position, and upon realizing it was in obvious distress, the Swedish interceptors escorted the Blackbird, with an armed pair of Viggens, flown by Lars-Eric Blad and Bo Ignell, relieving Sjöberg and Möller, and staying with the Blackbird until it reached Danish airspace, where American F-15 Eagles based in West Germany met and escorted the SR-71 to Nordholtz Airbase, Denmark, where it landed safely. After 30 years of classification, the details of the historic event were made public, and the four Swedish pilots were awarded the US Air Force’s Air Medal at a ceremony in Stockholm on November 28, 2018, with retired Lt. Col. Tom Veltri at the ceremony to thank the Swedish pilots for saving him and Lt. Col. Noll.
While the Viggen was in service with the Swedish Air Force, Saab attempted to offer for foreign export. One proposal was the Saab 37E Eurofighter (unrelated to the Eurofighter Typhoon) for the USAF Air Combat Fighter (ACF) competition, where it was in competition with other U.S.-European designs to replace the Lockheed F-104 Starfighter. However, on January 13, 1975, it was ultimately decided that the General Dynamics YF-16 Fighting Falcon would be selected for the ACF program, making the F-16 one of NATO’s standard fighting aircraft.
Saab also tried to export the Viggen to India, as well as offering a production license for the aircraft to be built in India. However, the United States objected to the export of an aircraft to India that utilized technologies developed by the United States, such as the Pratt & Whitney JT8D/Volvo RM8 engine, which the US refused to give an export license for India. As such, the proposal was dropped, and the Indian Air Force selected the Anglo-French SEPECAT Jaguar attack aircraft. Another propped customer for the Viggen was the Royal Australian Air Force (RAAF), whose aircraft would have been the Saab 37AU and would carry the AIM-54 Phoenix missile. However, the Australian government decided instead to order the F/A-18 Hornet instead.
With the end of the Cold War, the Viggen remained Sweden’s most advanced multirole aircraft, with upgrade packages keeping the aircraft’s avionics and weapons system up to date. But at this time, a new era for Swedish military aviation began with the introduction of the Saab JAS 39 Gripen (Griffin), which was introduced into service with the Swedish Air Force in 1996. The Gripen’s introduction marked the gradual retirement of the Saab 37 Viggen, with the last front line Viggen being retired on November 25, 2005. Ten SK 37 trainers were converted between 1998 and 2000 for use as electronic warfare trainers to test the Gripen’s radar systems, and these SK 37Es were the last Viggens in service with the Swedish Air Force when they were retired in June 2007.
Today, there are several Viggens that have survived to be preserved in museums. Many of these remain in Sweden on static display at places such as the Swedish Air Force Museum (Flygvapenmuseum) at Malmen Airbase in Linköping just outside Stockholm and the Söderhamn F15 Flygmuseum and the Aeroseum near Gothenburg. There are also two examples (AJS 37 s/n 37098 and SK 37 s/n 37809) that are maintained in airworthy condition and flown by the Swedish Air Force Historic Flight maintained by the Skaraborg Air Wing (F 7) in Såtenäs with the civilian registrations SE-DXN and SE-DXO.
Other examples are on static display outside Sweden at the Polish Aviation Museum in Krakow, the Estonian Aviation Museum in Tartu, the Newark Air Museum in Newark, England, and the French Air and Space Museum at Paris-Le Bourget Airport, France among others.
In essence, the Saab 37 Viggen remains one of the most remarkable jets of the Cold War, and one of the most successful aircraft in Swedish aviation history. It gained the respect of its pilots and maintainers, defended the skies of Sweden for over 30 years, and established its legacy on the history of aviation.
Today in Aviation History is a series highlighting the achievements, innovations, and milestones that have shaped the skies. All the previous anniversaries are available HERE
