Saab 37 Viggen

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See also the Saab 9-3 Viggen automobile
JA 37 Viggen
Swedish Air Force JA 37
Type Fighter-bomber
Manufacturer SAAB
Maiden flight 1967-02-08
Introduced 1971-06-21
Retired 2005-11-25
Status Retired
Primary user Swedish Air Force
Number built 329

The Saab 37 Viggen (The Thunderbolt) is a Swedish fighter aircraft manufactured between 1970 and 1990 to replace the Saab J 35 Draken.

Contents

[edit] Development

The first studies aimed at developing a successor to the Draken were carried out between 1952 and 1957 involving the legendary Finnish aircraft designer Aarne Lakomaa. Construction started in 1964, with a first prototype maiden flight in 1967. The aim was to produce a robust single-engined fighter with excellent STOL performance that could be operated from improvised facilities such as roads and highways in the event of nuclear attacks on major installations. Other requirements included supersonic ability at low level, Mach 2 performance at altitude, and the ability to make short landings at low angles of attack (to avoid damaging improvised runways).

To meet these design goals, Saab selected a radical canard configuration: a conventional delta wing with small, high-set canard wings. Canards have since become common in fighter aircraft, notably with the Eurofighter Typhoon and the IAI Kfir. The Viggen canards are not moveable as control surfaces. The canard flaps are, however, deployed in conjunction with the landing gear to provide more lift. To withstand the stresses of no-flare landings, Saab made extensive use of titanium in the construction of the Viggen, specially in the fuselage; and incorporated an unusual wheel arrangement for the main landing gear, which has two tires in tandem. Such layout is common in airliners and cargo planes, but it is rare in fighters. The plane was designed from the beginning to be easy to repair and service, even for personnel without much training.

In 1960 the U.S. National Security Council, led by President Eisenhower, formulated a military security guarantee for Sweden. The U.S. promised to help Sweden militarily in case of a Soviet attack against Sweden. As a consequence of this Sweden and the U.S. signed a military-technology agreement. In what was known as the "37-annex" Sweden received access to advanced U.S. aeronautical technology. The access to large amounts of U.S. expertise made it possible to design and produce Saab 37 Viggen much faster and cheaper than would otherwise have been possible.[1]

The reason for this officially unexplained U.S. support was, according to the Ph.d research of Nils Bruzelius at the Swedish National Defence College, the need to protect U.S. Polaris submarines deployed just outside the Swedish west coast against the threat of Soviet anti-submarine aircraft.[2]

The cockpit and air intake of JA 37 Viggen
The cockpit and air intake of JA 37 Viggen

In the JA 37 version, power is provided by a single Svenska Flygmotor RM8B turbofan - essentially a licence-built version of the same Pratt & Whitney JT8D that powered commercial airliners of the '1960s like the DC-9 and the 727 but with an afterburner. The engine also incorporated a thrust-reverser to use during landings. Only Viggen and the Panavia Tornado carry both afterburners and thrust-reversers. Viggen featured a navigational computer, the Datasaab CK37 which by Swedish means was a significant technological achievement at that time. It utilised the STRIL 60 system.

The CK37 computer
The CK37 computer

The first operational squadron was established in 1972 at Såtenäs with the ground attack optimised version. After 110 of the original AJ 37 and 18 SK 37 two-seat trainers were delivered, 26 of the SF 37 reconnaissance version to replace the S 35 Draken in 1975, and another 26 of the SH 37 maritime reconnaissance and strike version were built in 1974, replacing the S 32C Saab Lansen.

Although the Viggen was offered for sale worldwide, and regarded as a very competent aircraft, no export sales occurred. Reasons to explain Saab's failure to sell a competitively priced and well-respected aircraft include the Swedish government's relatively strict controls on arms exports to undemocratic countries, potential customers' doubts about continuity of support and supply of spare parts in the event of a conflict disapproved of by Sweden, and strong diplomatic pressure of larger nations. United States blocked an export of Viggen to India in 1978 by not issuing an export license for the RM8/JT8D engine, forcing India to choose the SEPECAT Jaguar instead.

The Viggen saw initial service in natural metal, later on receiving an extremely elaborate disruptive camouflage scheme; and then a light/dark gray on its final days.

The final Viggen variant was the JA 37 interceptor entering service in 1980. The last of 149 JA 37s was delivered in 1990. Various upgrades have been performed over the years, mainly to cockpit equipment, weapons and sensor fit.

Between 1998 and 2000, ten Sk37 trainers were converted to Sk37E electronic warfare trainers to replace the aging J32E Lansen.

The Viggen has been phased out in favor of the advanced later generation Gripen and flew its last flight in 25 November 2005.

[edit] Trivia

  • Burt Rutan named his VariViggen kit aircraft after the Saab Viggen.
  • Viggen, or a "Vigg" is also a tufted duck (Aythya fuligula), which is found in Sweden. Coincidentally, "Canard" is French for duck.
  • The name 'Viggen' has a mythological background: it is the clap of Mjolnir, Thor's hammer.

[edit] Operators

[edit] Specifications (JA 37 Viggen)

Orthographically projected diagram of the Saab JA 37 Viggen.

General characteristics

  • Crew: One
  • Length: 53 ft 9 in (16.4 m)
  • Wingspan: 34 ft 9 in (10.6 m)
  • Height: 19 ft 4 in (5.9 m)
  • Wing area: 500 ft² (46 m²)
  • Empty weight: 26,900 lb (12,200 kg)
  • Loaded weight: lb (kg)
  • Max takeoff weight: 44,000 lb (20,000 kg)
  • Powerplant: 1× Volvo RM8B afterburning turbofan, 16,200 lbf dry, 28,110 lbf afterburning (72.1 kN / 125.0 kN)

Performance

Armament

[edit] References

  1. ^ Hemliga atomubåtar gav Sverige säkerhetsgaranti Framsyn 2005, Nr. 1 (The Swedish Defence Research Agency’s bi-monthly publication)
  2. ^ Hemliga atomubåtar gav Sverige säkerhetsgaranti Framsyn 2005, Nr. 1 (The Swedish Defence Research Agency’s bi-monthly publication)

[edit] External links

[edit] Designation sequence

Saab 17 (bomber/dive-bomber)- MFI-15 Safari- Saab 18 (bomber)- Saab 21 (push-prop)- Saab 21R (jet)- Saab 29 Tunnan- Saab 32 Lansen- Saab 35 Draken- Saab 37 Viggen- Saab 39 Gripen

[edit] Related content

 

 

 

Related lists

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