Saab 37 Viggen

The Saab 37 Viggen ("Thunderbolt") is a Swedish single-seat, single-engine, short-medium range combat aircraft. Development work on the type was initiated at Saab in 1952 and, following the selection of a radical delta wing configuration, the resulting aircraft performed its first flight on February 8th 1967 and entered service in June 21st 1971. The Viggen holds the distinction of being the first canard design to be produced in quantity.

Several distinctive variants of the Viggen were produced to perform the roles of strike fighter (AJ 37), aerial reconnaissance (SF 37), maritime patrol aircraft (SH 37) and a two-seat trainer (SK 37). In the late 1970s, the all-weather fighter-interceptor aircraft JA 37 variant was introduced. In November 2005, the Viggen was retired from service by the Swedish Air Force, the sole operator of the type, having been replaced by the newer Saab JAS 39 Gripen.

Variants

 * AJ 37: Primarily a single-seat ground-attack fighter aircraft (AJ: Attack-Jakt), with a secondary fighter role. RM8A powerplant. PS 37A radar. First delivery in mid-1971, 108 built, with serial numbers 37001-37108. 48 airframes upgraded to AJS 37. Partially decommissioned in 1998.
 * SK 37: Two-seat trainer aircraft (Sk: Skol) with no radar and reduced fuel. First flight on 2 July 1970. 17 built, with delivery from June 1972, serial numbers 37801-37817. Decommissioned in 2003, 10 airframes converted to SK 37E.
 * SF 37: Single-seat photographic reconnaissance aircraft (SF: Spaning Foto), with radar replaced by battery of cameras in nose, with provision for additional reconnaissance pods. It made its first flight on 21 May 1973. 28 built, with deliveries from April 1977, serial numbers 37950-37977. 25 airframes upgraded to AJSF 37. Partially decommissioned in 1998.
 * SH 37: (SH- Spaning Hav, reconnaissance sea) Single-seat maritime reconnaissance and strike aircraft, equipped with PS-371A radar. 27 built, with delivery from June 1975, serial numbers 37901-37927. 25 airframes upgraded to AJSH 37. Partially decommissioned in 1998.
 * Saab 37E Eurofighter: Proposed NATO replacement of F-104 Starfighter in 1975, none built.
 * Saab 37X: Proposed export version offered to Norway in 1967–68, none built.
 * JA 37: Primarily a single-seat all-weather interceptor fighter, with a secondary attack role. Its first flight was on 27 September 1974 with the first deliveries starting in 1979, serial numbers 37301-37449. A 10 cm (4 in) stretch in the shape of a wedge wider at the bottom than on the top of AJ 37 fuselage between canard and main wing. PS 46A LD/SD radar. Partially decommissioned in 1998, some upgraded to JA 37D.
 * AJS/AJSF/AJSH 37: Upgrade of some AJ/SF/SH 37 between 1993 and 1998. Avionics and software upgrade. 48 AJ 37 airframes modified. 25 SH 37 airframes modified. 25 SF 37 airframes modified. Decommissioned in 2005.
 * JA 37C: Upgrade of older JA 37, avionics and software upgrade as well as the integration of countermeasures.
 * JA 37D: Upgrade of older JA 37 between 1993 and 1998, avionics and software upgrade. Rb99 air-to-air missile (AIM-120 in Swedish service) integrated. 35 airframes modified.
 * JA 37DI: JA 37D with avionics and software modified for international duties. Instruments labeled in English and feet/knots instead of meter/kmh. 20 airframes modified.
 * SK 37E: Electronic warfare trainer, conversion of 10 obsolete SK 37 trainers from 1998 to 2000, serial numbers 37807-37811 & 37813-37817, decommissioned in 2007.

Users

 * Sweden
 * Swedish Air Force