The SAAB JA-37 Jaktviggen (Fighter Viggen) is the dedicated interceptor version with a secondary attack capability of the superlative SAAB 37 Viggen (Thunderbolt) family, and is suffciently different from its predecessors to be treated separately. Like the AJ-37 (the Attack-Viggen) from which it derived, the JA-37 was also required to operate from short runways or lengths af straight road with minimum turn-round time and a high level af reliability even maintained only by modest ground support elements including a high proportion of conscripts. Sweden is a large country, and the obvious solution to its air-defense requirements would have been the construction of the AJ-37 in large numbers for locations at strategically placed air bases. This was clearly impossible for financial reasons, and was also seen as operationally flawed as the required bases would have been vulnerable to pre-emptive attack as well as very costly.
The Swedish solution was therefore the creation of the STRIL-60 system as a high-quality network of air-defense radars and associated command and communication systems for the effective defense of the country using secure data-links to provide effective control of limited numbers of warplanes which, in times of crisis or war, would be redeployed from their fixed and therefore vulnerable air bases to any of a large number of predetermined stretches of straight road. Here they would be considerably less vulnerable but still well placed to undertake the aerial defense of the country. The first JA-37 flew in November 1977 and went into service in 1979. The JA-37 is operated by the Swedish Air Force (Flygvapnet) and it possesses 149 planes.
Specifications
for JA-37 Jaktviggen
| Length | 53 ft 9½ in (16.40 m) |
| Weight | Normal TOW 37480 lb (17000 kg) |
| Powerplant | One Volvo Aero Corporation RM8B turbofan rated at 28101 lb (125.0 kN) |
| Armament | One 30 mm Oerlikon KCA revolver-type cannon |
| Ordnance | Up to 13228 lb (6000 kg) of disposable stores including Rb 71 Skyflash, Rb 24, Rb 74 Sidewinder, Rb 99 AMRAAM (in later variants), Rb 28 Falcon, Rbs 15 anti-ship missile, Rb 05 and Rb 75 ASM, free-fall or fragmentation bombs of various sizes |
| Top speed | Mach 2.1 |
| Range | 621 miles (1000 km) |
| Ceiling | 60040 ft (18300 m) |
| Climb rate | Climb to 32810 ft (10000 m) from brakes off in 1½ min |