Few aircraft may have a more fitting name than the Saab 37 “Viggen,” which means “Thunderbolt” and alludes to the three-forced lightning produced by Thor’s hammer. During the darkest years of the Cold War, Sweden maintained a strict neutrality stance but was well-prepared for a potential war with the Soviet Union.
Stockholm also upheld a strong policy of domestic design, development, and production of its frontline military equipment, particularly combat aircraft for the Flygvapnet, to aid in that effort. The Saab 37’s moniker, “Guardian of Neutrality,” fits it perfectly. In the early Cold War era, the Royal Swedish Air Board demonstrated its ability to forge ahead of other countries. In 1958, it started developing what was then known as “System 37,” which was created to be integrated with the STRIL 60 air-defense infrastructure of radars, computers, and displays.
The result was the single-engine, single-seat Saab 37 Viggen fighter, which had a low double delta wing and two canards with flaps. The first of seven 37 prototype/pre-production Viggens, intended to replace the outdated Saab J35 Draken, was rolled out in November 1966, and the aircraft made its first flight in February of the following year.
The Viggen joined the Swedish Air Force in 1971 after rapid advancement had been made. It was the first canard-designed aircraft to be mass-produced, and at the time of its introduction and up until the Panavia Tornado entered service in 1981, it was also the most technologically advanced fighter jet in Europe.
Advanced and Rugged Warbird: The Saab 37 was a single-seat aircraft with cutting-edge avionics, including a central computer and heads-up display to take the position of a human navigator. The CK 37 (centralkalylator 37), the first airborne computer to use integrated circuits, was among them.
The eight thousand words “vocabulary” memory unit of the miniature digital computer allowed it to give the pilot automatic navigation, target location, and even firing control. Additionally, it was connected to the STRIL 60 ground defense network.
The Viggen was the only European aircraft of its time with such sophisticated radar, a wide speed range, and a full “kit” of avionics and weaponry. The Saab S37 was built to be tough in addition to being a highly technological aircraft. The Royal Swedish Air Board also demanded that the multirole fighter be “battlefield friendly,” including the capacity to take off and land on short runways and, in an emergency, even use highways and off-road routes.
Stockholm was determined to mount a substantial defense in case the Soviets invaded, therefore the new fighter also needed to be simple for conscript-level personnel to assist refueling.
Additionally, the Saab 37 Viggen lived true to its lightning bolt name. A Volvo RM 8 turbofan, which was essentially a license-built version of the Pratt & Whitney JT8D engine that propelled commercial airliners in the 1960s, provided the aircraft with power. The S37 received an afterburner, and the airframe included a thrust reverser that could be used during landings.
The Saab 37 has the distinction of being the first aircraft to have both an afterburner and a thrust-reverser, a feature later used on the commercial airliner Tornado and Concorde. The Viggen was only capable of short takeoff and landing (STOL) from airstrips that were around 500 meters long.
The aircraft had a service ceiling of 18,000 meters, a top speed of Mach 2.1 (1,385 miles per hour), and a maximum range of 2,000 kilometers with internal fuel. A rate of ascent of 203 meters per second was given by the RM 8 engine. The Viggen was a true fighter with a 30mm Oerlikon KCA gun and six underwing/under-fuselage hardpoints for air-to-air and air-to-surface weaponry, which initially comprised Rb04E or Rb05A missiles for the attack and Rb27, Rb28, and Rb324 missiles for defense. Typical late-stage weapon load-outs also included RB71 Skyflash missiles, AIM-9 Sidewinders, and AIM-120 AMRAAM missiles.
The Viggen was initially intended for 800 units, but the order was reduced due to expenses after it was decided not to sell the Viggen for export. The United States also prevented a potential sale to India by refusing to give an export license for the engine since it employed American technology. Initially, Saab had marketed the aircraft all over the world, but Swedish export rules were one obstacle.
Only 329 Viggens of all models, combined, were ever produced, and they flew for the Flygvapnet until 2005. The fighter was never employed in battle and less than twenty modern aircraft remain today, and most of them are housed in military and aviation museums abroad.