The SAAB 37 Viggen

v1.0.7 / 01 mar 16 / greg goebel

* During the Cold War, Sweden pursued a policy of neutrality between East and West, and went to considerable lengths to build up a defense force to back up their neutrality. One of the major components of this force was a series of combat aircraft built by SAAB, and one of the most impressive of this series was the "SAAB 37 Viggen (Thunderbolt)", a multirole combat aircraft that was the backbone of Swedish air power from the 1970s to the end of the century. This document provides a history and description of the Viggen.

SAAB JA 37 Viggen



* In the early 1960s, Sweden was looking for a multirole fighter that could replace the SAAB 32 Lansen in the strike role and the SAAB 35 Draken in the air defense and reconnaissance roles. The specifications for the new aircraft were ambitious:

SAAB had been considering various designs to follow the Draken since 1952. The company was able to submit a proposal to meet the specification, the "SAAB System 37", in February 1962. The design featured a canard configuration that offered better short-field operation than a traditional delta wing, and a powerful RM8 afterburning bypass turbojet engine with a thrust reverser to cut down landing roll. The SAAB 37 would feature an automated microwave instrument landing system (ILS) to help perform short landings, and would also be equipped with state-of-the-art avionics and combat systems. In addition, since Sweden was and remains strongly reliant on large numbers of reservists who would be called up in time of war, the SAAB 37 was designed to be easily maintained by ground crews with relatively limited training.

The Svenska Flygvapnet (Swedish Air Force) liked the proposal and gave the go-ahead on 28 September 1962 for full development of the "Viggen (Thunderbolt)", as the type was named, with details released to the public in December 1962. Incidentally, "Viggen" actually has a somewhat more specific meaning, being the clap of thunder produced by the thunder god Thor's hammer Mjoelnir, but "Thunderbolt" gives the desired impression in any case.

Several different lines of Viggen development were envisioned:

Six single-seat AJ 37 Viggen prototypes and one two-seat Sk 37 Viggen prototype were ordered in 1965, at about the same time a mockup of the aircraft was displayed to the media. The first single-seat prototype was rolled out on 24 November 1966 and performed its initial flight on 8 February 1967, with Erik Dahlstrom, SAAB's chief test pilot, at the controls. Dahlstrom stated that the Viggen handled as pleasantly as a sportsplane. Pilots would always like the Viggen's handling, particularly in comparison to that of the more challenging Draken, but the steep landings were tricky to master, and even Dahlstrom scraped the tail at least once.

The second prototype followed on 21 September 1967, and the third on 29 March 1968. The last of the six single-seat prototypes was in the air by April 1969, with this machine being very close to production AJ 37 specification. The initial prototype had been involved in a fatal "sheer dumb bad luck" accident on 31 May 1968, when Lennart Fryoe dropped a flight checklist while preparing to take off and accidentally triggered the ejection seat; his parachute didn't open fully and he was killed. The aircraft kept on rolling until it hit a drainage ditch and hangar, but it was repaired and returned to service. The fourth prototype was lost in an accident on 7 May 1969, with another prototype built to take its place. It is unclear if this prototype was an additional aircraft or part of the seven originally ordered.

A production order for 175 AJ 37 / SF 37 / SH 37 machines had already been placed on 5 April 1968. Initial flight of the first production AJ 37 was on 23 February 1971, with initial service deliveries to the Flygvapnet in June 1971.



* The AJ 37 attack variant of the Viggen, where "AJ" stands for "Attack Jakt / Strike Fighter", was the first of the series to go into service, and makes a useful baseline for further discussion.

The AJ 37 had a spikelike fuselage, with:

Overall construction was of aircraft aluminum honeycomb, with titanium where required, such as engine firewalls. The Viggen was arguably less elegant in appearance than its predecessor, the SAAB 35 Draken, or its successor, the SAAB 39 Gripen, but it had a certain solid, businesslike, and combative style of its own. However, the extensive use of aluminum honeycomb made it surprisingly light for its size.

The wing had a somewhat complicated form, designed as a double delta with something of a "hoop skirt" appearance in planform, and a dogtooth on each outer span. The dogtooth was added to improve longitudinal stability when carrying external stores. Each dogtooth was further marked by a bullet fairing for a radar warning receiver (RWR) antenna. There were two-section hydraulically actuated elevons on the trailing edge of each wing.

The canards directed turbulent airflow over the main wing at low speeds, lowering the stall speed on landings. They had no dihedral and were fixed at a few degrees of incidence, but had trailing-edge flaps to improve takeoff performance. The canards on the first prototype had a noticeable dihedral as the aircraft was initially rolled out, but the dihedral was eliminated before the machine took to the air. The tailfin was fixed, with a one-piece rudder. The tailfin folded to the left to allow the aircraft to be stowed in hardened shelters at field bases. There was a fixed ventral fin under the tail.

The AJ 37 featured tricycle landing gear, all gear featuring two wheels. The nose gear retracted forward. Each main gear assembly unusually featured its two wheels in tandem to reduce its depth for storage in the wing, and retracted inward from the wing towards the fuselage, with the main gear struts telescoping during retraction for a tighter fit. The landing gear was heavily shock-absorbed to permit steep "smackdowns" for short landings. Landings were said to be "firm" and apparently were much along the lines of carrier landings, except that the landing strip wasn't moving.

The RM8A afterburning turbofan was actually at the core a Pratt & Whitney JT8D-22 commercial turbofan, used on the Boeing 727 and Douglas DC-9 airliners, built under license by Svenska Flygmotor (later Volvo Flygmotor) and fitted with a Swedish-designed afterburner with thrust reverser. It was said to be the first production engine to ever have such a combination of features. The engine provided 115.7 kN (11,800 kgp / 26,015 lbf) afterburning thrust. The thrust reverser featured three "jaws" that snapped shut when the nose gear touched down, blasting the exhaust forward through three slots around the fuselage under the tail.

It is unclear how the engine was started; cutaways of the machine do not show anything resembling an auxiliary power unit. The Viggen did have a ram-air turbine for emergency flight power, fitted to a door under the trailing edge of the left canard. The RAT popped out when hydraulic power was lost and (for some puzzling reason) when the landing gear was extended. There was a fuel tank in each wing, a saddle tank over the engine, a tank on each side of the engine, and a tank behind the cockpit, for a total of six tanks. There was no provision for inflight refueling, since that would have implied a "force projection" capability not in line with Sweden's defensive posture.

The pilot sat under a rear-opening clamshell canopy behind a one-piece windshield hardened against birdstrikes. There was a prominent humped dorsal spine running back from the canopy; most of the prototypes had a less prominent straight spine, but the enlarged spine improved transonic handling and was adopted for production.

SAAB AJ 37 Viggen

The Viggen was originally fitted with a SAAB Mark 2 rocket-boosted ejection seat with zero-altitude capability, but as demonstrated by the accident that killed Lennart Fryoe, the aircraft had to be moving at 75 KPH (47 MPH) or more for the seat to work reliably. The Mark 1 seat, incidentally, was the development version and was apparently never operationally fielded on any aircraft. It is an indication of the Swedish "do it ourselves" mentality that SAAB actually developed their own ejection seat, when a all-but-standard British Martin Baker seat would have probably been as good or better from the technical and cost standpoints.

   _____________________   _________________   _______________________
   spec                    metric              english
   _____________________   _________________   _______________________

   wingspan                10.60 meters        34 feet 9 inches
   wing area               46.0 sq_meters      495.16 sq_feet   
   canard span             5.45 meters         17 feet 10 inches
   canard area             6.20 sq_meters      66.74 sq_feet   
   length                  16.30 meters        53 feet 6 inches
   height                  5.80 meters         19 feet

   empty weight            11,800 kilograms    26,015 pounds
   normal weight           15,000 kilograms    33,070 pounds
   MTO weight              20,500 kilograms    45,195 pounds

   max speed at altitude   2,125 KPH           1,320 MPH / 1,145 KT
   service ceiling         18,300 meters       60,000 feet
   takeoff run             400 meters          1,310 feet
   landing run             500 meters          1,640 feet
   combat radius           1,000 kilometers    620 MI / 540 NMI
   _____________________   _________________   _______________________

The control layout was analog, as would be expected of aircraft of its period, but featured a Svenska Radio / Ericsson (SRA) head-up display (HUD) for primary flight data, including displays generated by the instrument landing system to help guide the aircraft down. The most significant element in the AJ 37's avionics suite was its Ericsson PS-37A monopulse X-band radar, which was primarily focused on air-to-ground and navigation, though it had limited air-to-air capabilities. The rest of the avionics was impressive -- or at least it was for its era -- and included:

The AJ 37 had seven stores pylons, including a centerline pylon; a pylon under each engine inlet; and two pylons on each wing outboard of the main landing gear. There was provision for a third outboard pylon under each wing. Maximum external load was a hefty 7,000 kilograms (15,400 pounds). An external fuel tank was almost always carried on the centerline pylon; it seems that was the only "wet" pylon. Primary stores initially included:

SAAB AJ 37 stores

As mentioned, the Viggen was designed to be easy to maintain. It had over 100 access panels, with the nose cone sliding forward to give access to the radar system, and the rear fuselage could be quickly pulled off to give access to the engine. Most of the access panels could be reached without use of a ladder or service scaffold. Systems were modular to ease servicing and upgrades. A "built-in test system" was integrated into the aircraft, with specialized servicing vehicles produced to help find and fix faults.

* A total of 109 production AJ 37s was built, with the type equipping six squadrons. Although prototypes and early production aircraft flew in natural metal finish, in service AJ 37s were painted gray on the bottom and with a "splinter" camouflage scheme on top, featuring a four-color pattern of tan, light green, dark green, and dark blue. The Flygvapnet referred to this color scheme as "fields and meadows" and it was meant to help conceal the aircraft at their dispersed bases. All other Viggen variants except most of the JA 37 interceptors also featured this color scheme.

There were a number of losses of AJ 37s in 1974 and 1975 due to wing spar failures. As it turned out, the first 27 machines had been built with lighter wing spars, and so the 21 survivors were rebuilt with stronger spars. Oddly, though the Viggen was easier to fly than the Draken, the Viggen's accident rate was higher. One interesting accident took place on 28 September 1982, when a pilot was taking off from Norrkoeping and suddenly encountered a herd of elk that had wandered onto the runway. There was a collision with one of the elk, with the aircraft suffering minor damage while the elk ended up as venison. One wonders if the pilot was at least tempted to put a "kill marking" on his machine.

In the early 1990s, a decision was made to update a number of AJ 37s and some other Viggen variants to the "AJS 37" multirole configuration, of which more is said below. The last operational flight of a true AJ 37 was in March 2000.



* A single prototype of the SF 37 dedicated reconnaissance variant of the Viggen was built, performing its first flight on 21 May 1973. The "SF" stood "Spanings Foto / Photo Reconnaissance". Deliveries to the Flygvapnet began in early 1977, with a total of 28 machines handed over by early 1980. They replaced the Saab S 35E Draken in the photo reconnaissance role.

The SF 37 was basically a modified AJ 37 Viggen attack variant. It was fitted with a distinctive camera nose and external reconnaissance pods. The nose accommodated seven vertical and oblique cameras, including an infrared linescanner, and a data recording unit. The nose camera fit could be configured for low altitude or high altitude reconnaissance missions. The pilot had a periscope to gives him a view of the ground directly below to help take vertical shots. Reconnaissance pods were carried on the pylons under the engine inlets, with options including a "Red Baron" multisensor night reconnaissance pod with an electronic strobe photoflash, or a forward-looking long-range optical (LOROP) camera pod.

Unsurprisingly, the SF 37 was not fitted with radar. It was fitted with the RWR and carried countermeasures pods plus Sidewinders for self-defense, but it had no radar for targeting and it does not appear to have had a gunsight capability.

* The SH 37 variant has been described as maritime reconnaissance variant, but it might also might been described as a maritime patrol and strike variant. The "SH" stood for "Spanings Havsoevervakning / Coastal Surveillance & Reconnaissance."

The SH 37 prototype was a rebuild of the third AJ 37 prototype, and performed its first flight in its new configuration was on 10 December 1973. Externally, the SH 37 was very difficult to distinguish from the AJ 37. The most significant difference was fit of the improved Ericsson PS-371/A radar with greater range and optimizations for maritime surveillance. The radar display was recorded on a video camera for post-mission analysis. A second camera was similarly used just to log the flight data corresponding to a target location, while the pilot uses a tape recorder to log comments. An improved data processor was also fitted.

The SH 37 could carry the Red Baron or LOROP reconnaissance pods. Initially, the plan had been to build a single reconnaissance Viggen that could perform the mission of both the SF 37 and the SH 37, but it proved impossible to cram both radar and cameras into the same nose. The SH 37 also had the RWR and could carry countermeasures pods plus Sidewinders for self-defense, and could carry all offensive weapons qualified for the AJ 37. 27 SH 37s were built between 1977 and 1979. Flygvapnet reconnaissance squadrons operated a mix of SF 37s and SH 37s.



* Although a two-seat conversion trainer wasn't considered for the Viggen originally, the Flygvapnet decided that it would be a good idea after all. The result was the "Sk 37" two-seat trainer, where "Sk" stood for "Skol / School". As mentioned earlier, the seventh of the first seven Viggen prototypes was to be built as a two-seater, though because of the loss of the fourth single-seat prototype it is a bit unclear if the first trainer was actually the seventh or the eighth machine. In any case, the first two-seater performed its first flight on 2 July 1970, somewhat behind the original schedule, with Pers Pellebergs at the controls. Initial deliveries of the Sk 37 were in June 1972, and a total of 17 production Sk 37s was built.

SAAB SF 37, Sk 37 Viggen

The Sk 37 used the AJ 37 airframe. An independent, raised, second cockpit was added behind the front cockpit, with the trainee in the front cockpit and the instructor in the rear cockpit. The instructor had twin periscopes to improve his forward view. The second cockpit was fitted by removing some fuel tankage; the Sk 37 normally flew with a centerline tank to compensate. The Sk 37 also featured a 10 centimeter (4 inch) tailfin extension, with the trailing edge sweep of the extension reversed from the rest of the tailfin. The tailfin extension was not initially fitted to the prototype.

The Sk 37 did not have radar, navigating using Doppler and later DME, and though it could carry external stores its combat capabilities were limited by the lack of radar targeting and its short range. While it retained the bullet fairings for the RWR, it was apparently not fitted with the RWR gear itself.



* Of the six AJ 37 prototypes, five of them were subsequently modified to act as prototypes for the JA 37 interceptor ("Jakt / Fighter") variant of the Viggen, the first of these modifications performing its initial flight on 27 September 1974. An initial production order for 30 JA 37s had been placed a few days before that. A fifth JA 37 prototype, a new-build machine, flew in 1975 and was to preproduction standard. The first production aircraft performed its initial flight on 4 November 1977, with Per Pellebergs at the controls, with initial service deliveries in 1980. A total of 149 production JA 37s was built up to June 1990 -- the end of production for the Viggen, with 338 built, including the eight prototypes.

The JA 37 was very similar to the AJ 37 externally, but it was, if arguably not a "second generation" Viggen, certainly a half-step forward. SAAB was able to take their time on development of an interceptor variant because the Flygvapnet felt the Draken would be able to handle that duty well enough over the short term.

The major visible distinguishing characteristic relative to the AJ 37 was that the JA 37 had the 10 centimeter (4 inch) tailfin extension of the SK 37 two-seater. It would take a keener eye to have noticed that the JA 37 was stretched by 10 centimeters (4 inches) ahead of the wing to accommodate a more powerful RM8B powerplant, with 125 kN (12,750 kgp / 28,110 lbf) afterburning thrust. The additional power was regarded as important for the air-defense role, and the engine also had improved surge tolerance at high altitude and speed.

Each wing had four elevon actuators instead of three as on other Viggen subtypes, to permit improved combat maneuvering, and there was some structural reinforcement. Another update was fit of a SAAB Mark 3 ejection seat, with true "zero zero (zero altitude zero speed)" capability; this new seat was retrofitted to other Viggen variants. The empty weight of a JA 37 was about 400 kilograms (880 pounds) more than that of an AJ 37.

SAAB JA 37 Viggen

Avionics systems were largely different. The primary sensor was the Ericsson PS-46/A medium-pulse rate, pulse-Doppler, X-band, multi-mode radar, with a range of about 48 kilometers (30 miles) and "look down / shoot down" capabilities, to allow it to find and target low-altitude intruders trying to hide in ground clutter. It was a state-of-the-art system at the time of its introduction. The rest of the JA 37's avionics suite included:

One of the few items it had in common with AJ 37 avionics was the SRA HUD. However, in contrast to the AJ 37, the JaktViggen had a partial glass cockpit, with a head-down display (HDD) and a tactical display. Another visible difference from the AJ 37 was that the JA 37 had built-in armament, in the form of a Swiss Oerlikon KCA 30-millimeter cannon with 150 rounds of ammunition, fitted in a belly pack and offset to the left to clear the centerline pylon. A radar gunsight was used to aim the cannon. The Oerlikon cannon had far more range and punch than the Aden cannon carried in pods by the AJ 37, with the projectiles having about eight times as much kinetic energy.

The JA 37 retained the seven stores pylons of the AJ 37. Four Sidewinders could be carried -- on the outer wing pylons and the pylons under the engine inlets -- along with two Rb71 Skyflash semi-active radar homing medium-range AAMs, this weapon being a license-built copy of the British Aerospace (BAE) Skyflash, which in turn was an improved version of the US AIM-7 Sparrow AAM. Some sources claimed that an alternate configuration of four Skyflash and two Sidewinder AAMs could be carried as well, but it appears this was an error, sometimes shown in paintings and drawings but very hard to find in photographs.

As with other Viggen variants, an external tank was almost always carried on the centerline pylon. Four six-round Bofors M70 135-millimeter unguided rocket pods could be carried in a secondary strike role, the pilot using the gunsight for aiming. The JA 37 lacked the capability to perform targeting for most other attack stores, just as the AJ 37's radar could not provide guidance for the Skyflash AAM.

SAAB JA 37 Viggen

In service, JA 37s were usually painted in a number of air-superiority color schemes, with the Flygvapnet eventually settling on a tidy two-tone gray scheme -- though apparently some did sport the splinter camouflage used by other Viggen variants. At its peak, the JA 37 equipped five air-defense squadrons. An export version, the "Saab 37E Eurofighter", was proposed in 1975 as a replacement for the F-104 Starfighter for a group of NATO nations, but the General Dynamics F-16 won the award. (This deal, incidentally, had nothing directly to do with the later multinational European Fighter Aircraft program.) In fact, although SAAB considered other possibilities for export sales, no Viggen was ever sold to another air arm.



* Viggens in service were given a continuous stream of mostly minor updates, generally in the form of improved avionics and software upgrades. One of the more important enhancements, performed in the late 1980s, was carriage on the AJ 37 of the US-designed AGM-65A Maverick ASM, license-built in Sweden as the "Rb75". It generally replaced the less sophisticated Rb05 ASM. A comparable upgrade, also performed in the late 1980s, provided support for the much improved AIM-9L Sidewinder AAM, capable of "all aspect" targeting instead of requiring a lock on the target's engine exhaust; the missile was built in Sweden as the "Rb74".

In 1992 the Swedish government approved a program to upgrade a total of 115 AJ 37s, SF 37s, and SH 37s to a multirole "AJS 37" configuration, with "AJS" standing for "Attack / Jakt / Spaning". The follow-on SAAB 39 Gripen was already flying by that time, but development was proving troublesome, with defense cutbacks following the end of the Cold War also promoting delays. Viggens needed to be upgraded to keep them current and capable until the Gripen could enter squadron service.

The specific driver for the upgrade was the development of new weapons for the Gripen, such as the DWS 39 gliding submunitions dispenser, and in particular the Rb15F antiship missile -- a vastly improved derivative of the old Rb04, fitted with a turbojet engine and new, much smarter seeker. The Rb15F was developed with the Gripen in mind, but was ready for service well in advance of the SAAB 39. As long as the weapon was available, there was absolutely no reason not to field it, and fitting such kit to the Viggen would give Flygvapnet pilots useful systems familiarization for when they stepped up to the Gripen. It was determined that the old AJ 37 could carry the missile if the aircraft were fitted with a new Ericsson processor system and a MIL-STD 1553B digital databus. A little further thought showed that the same fit could be performed on the reconnaissance Viggens, and the result was the AJS 37.

Early press releases on the program gave the impression that the AJS 37 was to be a major upgrade, and that the aircraft upgraded would end up with a common configuration. That was reading too much into it, and the announced total of 115 upgrades was also something of an exaggeration, with only 98 conversions actually performed. Basically it was a middling sort of avionics and software upgrade that did not change the external appearance of any of the upgraded aircraft in any significant way, the major changes being to permit them to carry new stores. Modifications to the cockpit control layout were modest, and certainly did not involve fit of a true glass cockpit; there was no airframe service life extension program (SLEP).

The upgraded AJ 37, SF 37, and SH 37 machines acquired the new designations of "AJS 37", "AJSF 37", and "AJSH 37" respectively. All had:

Beyond that, the capabilities of the three types of machines retained considerable differences:

Re-deliveries of upgraded aircraft began in 1993 and were completed in 1996. Dedicated reconnaissance squadrons were phased out and reconnaissance machines incorporated into regular attack squadrons.

However, a special reconnaissance squadron of AJSF 37 Viggens was set up late in the decade to provide support for international peacekeeping missions, the Swedes having become a little more assertive in foreign military operations following the end of the Cold War. The "Swedish Air Force Rapid Reaction (SWAFRAP)" unit was set up in 2000, with the aircraft repainted in a two-tone gray color scheme, and quickly refitted with a NATO-compatible radio (revealed by a blade antenna on the spine) plus a Global Positioning System (GPS) navigation system receiver. The original navigation system was also modified to support far-ranging deployments with NATO forces. The SWAFRAP Viggens took part in some exercises, but were never operationally deployed before they were withdrawn in 2003. A new SWAFRAP squadron flying Gripens was set up in 2004.

* As with other Viggens, the JA 37 interceptor Viggens were continuously upgraded, in particular by being fitted with a datalink system in the mid-1980s. The Flygvapnet had developed the sophisticated STRIC ground-based defense datalink system; STRIC allowed Viggens to be vectored onto targets without using their own radar, giving them an element of surprise. STRIC also allowed ground controllers to read basic aircraft system status, and let pilots trade simple messages through the ground network. Other useful upgrades added:

The datalink and Rb74 upgrades required addition of switches to the control stick that eliminated the airbrake control, with the airbrakes wired shut. There were few complaints, since like most other delta-winged aircraft, the Viggen lost speed rapidly under sharp maneuvers and the airbrakes had rarely been used in the first place.

* In the late 1990s, a major upgrade program was implemented to convert surviving JA 37s to the "JA 37D" standard. Updates included:

A TARAS encrypted digital tactical radio system was considered but not implemented. With the improved avionics plus all-aspect Sidewinders and AMRAAM, nobody would have considered the JA 37D to be either out-of-date or a pushover. The JA 37D upgrade program was initiated in 1992, with the conversions beginning in the late 1990s. A total of 34 JaktViggens was converted.

* The Swedes really like to get their money's worth out of their aircraft, and when the Flygvapnet's J 32E Lansen electronic warfare (EW) machines were phased out in 1997, a decision was made to update ten of the fourteen surviving Sk 37s two-seaters to the "Sk 37E Stoer (Jammer) Viggen" EW configuration. This was actually a fairly substantial upgrade, including:

Work on the first of the ten "Erik" conversions began in late 1997, with an initial conversion flying in early 1998 and the last conversion performed in 2000. There was some thought to giving the Sk 37Es the same two-tone gray color scheme as the JA 37, but though one Erik was painted in this scheme, the decision was made that the old splinter camouflage scheme was fine.

The Stoer Viggen's primary mission was EW training, acting as an "electronic aggressor" for Swedish forces in training exercises. It could be fitted with laser reflector pods on the outer wing pylons to track "hits" when fired on by adversaries. The Sk 37E was capable of being used as an operational platform, but since a dedicated jammer aircraft tends to be more useful for offense than defense, that aspect of the Erik was downplayed.

* In the 21st century, the SAAB 39 Gripen rapidly displaced the Viggen from front-line service. Although the Viggen's predecessors had long service lives, and with upgrades the type was clearly still effective, defense cutbacks meant the Viggen was redundant and that its days were numbered. The last operational flight of the Viggen for the Flygvapnet was on 25 November 2005.

It was sad to see the Viggen go, but after almost three decades of service, it wasn't as though it had been cut off in its prime. The future career of the Viggen seems likely to be restricted to the role of museum display piece, though one or two are being kept on flight status for airshows and other public appearances.



* The following table gives Viggen variants and production quantities:


   type    built  upgraded  comments

   SAAB 37       8            prototypes, built to various configurations
   AJ 37       109            (initial) attack variant
   SF 37        28            photo-reconnaissance variant
   SH 37        27            maritime surveillance / combat variant
   Sk 37        17            two-seat trainer
   JA 37       149            interceptor variant

   AJS 37        -      48    upgraded AJ 37
   AJSF 37       -      25    upgraded SF 37
   AJSH 37       -      25    upgraded SH 37

   JA 37D        -      34    upgraded JA 37
   Sk 37E Stoer  -      10    SK 37 two-seater countermeasures upgrade


               338  TOTAL VIGGEN PRODUCTION

* The series of combat aircraft built by SAAB seem impressive enough at first sight. What makes them even more impressive is the realization that Sweden's entire population is about that of a major metropolis, distributed over a country about the size of California. As one author put it, imagine the mayor of New York City or Tokyo or London announcing that the city government was going to fund development and production of a combat aircraft. It puts the ambition of the effort into proper perspective.

SAAB SK 37 Viggen

One of the interesting observations about the Viggen was that, despite the fact that it used as much Swedish content as possible, it still used an American engine (at least at the core), and carried American and British designed missiles. The Swedes were clearly serious about their neutrality, but during the Cold War it was never exactly a case of sitting precisely on the fence: NATO was not the threat Swedish defense planners spent most of their time worrying about. There are rumors that there was always quite a bit of intelligence-sharing between Sweden and NATO, but it was kept a tight secret. One suspects the Soviets understood which way Sweden tilted perfectly well, but saw no reason to make an issue about it unless the Swedes were indiscreet.

* As concerns copyrights and permissions for this document, all illustrations and images credited to me are public domain. I reserve all rights to my writings. However, if anyone does want to make use of my writings, just contact me, and we can chat about it. I'm lenient in giving permissions, usually on the basis of being properly credited.

* Sources include:

Some comments were obtained from an online article by Swedish aviation enthusiast Urban Fredriksson.

* Revision history:

   v1.0.0 / 01 mar 04
   v1.0.1 / 01 mar 06 / Tweaked details, added Viggen withdrawal.
   v1.0.2 / 01 aug 06 / Review & polish.
   v1.0.3 / 01 aug 08 / Review & polish.
   v1.0.4 / 01 jul 10 / Review & polish.
   v1.0.5 / 01 jun 12 / Review & polish.
   v1.0.6 / 01 apr 14 / Review & polish.
   v1.0.7 / 01 mar 16 / Review & polish.