From Mach‑2 Dreams to Modern Multirole Flexibility
The Saab 37 Viggen lifted off for the first time on 8 February 1967 from Linköping, Sweden. Its design was driven by two bold requirements: supersonic performance at low altitude and Mach 2 capability at high altitude. When Rolls‑Royce cancelled the Medway engine, Saab turned to Volvo, which re‑engineered the Pratt & Whitney JT8D turbofan into the RM8 powerplant – complete with thrust reversers and an afterburner to meet the speed targets.
Revolutionary Canards and Folding Tail
The Viggen’s small forward‑mounted canards provided extra lift and, together with its double‑delta wing, gave the aircraft outstanding low‑level agility. Modern fighters such as the Rafale, Typhoon and Saab’s own JAS 39 Gripen now feature fully movable canards, a direct evolution of the Viggen’s concept.
Another forward‑thinking feature was the fully foldable vertical stabilizer. Sweden’s reliance on low‑profile mountain shelters – not aircraft carriers – demanded a tail that could be tucked away, a design cue that foreshadows today’s dispersed‑basing strategies.
Variant Evolution: From Attack to EW Trainer
The Viggen family grew into several specialised versions:
- AJ37 – Ground‑attack variant with “splinter” camouflage, capable of flying at 650 knots and as low as 10 m above the terrain.
- SF37 – Photo‑reconnaissance model with dedicated camera bays.
- SH37 – Maritime patrol/attack version equipped with nose‑radar and a 600 mm camera pod, able to carry two Rb.04 E anti‑ship missiles.
- SK37 – Two‑seat trainer, later upgraded to the SK37E “Stör Viggen” for electronic‑warfare (EW) training.
- JA37 – Air‑defence fighter, later modernised to the JA37DI “interoperability” standard with a new cockpit computer, colour displays and the AIM‑120 AMRAAM missile.
Modernisation as a Blueprint
During the 1990s the AJ37, SH37 and SF37 received a common upgrade – new weapon computers, expanded armament options (e.g., Rb15F anti‑ship missiles) and a multirole capability. This programme deliberately paved the way for the JAS 39 Gripen, Sweden’s next‑generation fighter.
The JA37DI’s datalink, colour cockpit screens and compatibility with NATO weapons such as the AIM‑120 illustrate a broader trend toward interoperable avionics and seamless integration into multinational exercises.
Future Trends Inspired by the Viggen Legacy
1. Distributed Baselines and Short‑Runway Operations
Designing aircraft to operate from 500 m runways and low‑profile shelters, as the Viggen did, is increasingly relevant for nations seeking resilience against base attacks.
2. Modular Airframes for Role Flexibility
The Viggen’s ability to switch from attack to reconnaissance, maritime patrol or EW training by swapping pods and software foreshadows today’s modular “plug‑and‑play” mission packages.
3. Integrated Digital Avionics
Saab’s early adoption of a digital central computer set a precedent for the highly networked cockpits seen in modern fighters, where automated decision‑making reduces pilot workload.
4. Interoperability with International Weapons
Upgrading to the AIM‑120 AMRAAM and adopting datalink standards demonstrates a clear path for legacy platforms to stay relevant alongside newer allies’ systems.
Did you know?
The Viggen was the first mass‑produced aircraft to feature canards, a design element now standard on many 4th‑generation fighters.
Pro Tip for Aviation Enthusiasts
When visiting the Swedish Air Force Historic Flight, seem for the Viggen with the distinctive “neergeklapte staart” – the folded tail is a visual reminder of Sweden’s innovative shelter strategy.
FAQ
- What engine powered the Viggen after the Medway was cancelled?
- Volvo adapted the Pratt & Whitney JT8D turbofan into the RM8, adding thrust reversers and an afterburner.
- Why does the Viggen have a folding vertical stabilizer?
- To fit into Sweden’s low‑profile mountain shelters, allowing operation from dispersed, improvised hangars.
- Which modern fighter inherited the Viggen’s multirole upgrades?
- The JAS 39 Gripen built on the Viggen’s multirole and digital avionics concepts.
- Can the older Viggen airframes still serve a purpose today?
- Yes – the SK37E “Stör Viggen” was repurposed for electronic‑warfare training, showing how legacy platforms can support modern EW curricula.
Explore More
Curious about the next step in Saab’s lineage? Read our deep dive on the Saab Gripen and how it builds on the Viggen’s heritage.
References
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