Saab 37 Viggen

AJ37, JA37, SF37, SH37 and Sk37

Origin: Saab-Scania AB. Linkoping, Sweden.

Type: (AJ) single-seat all-weather attack: (JA) all-Weather fighter: (SF) armed photo-reconnaissance: (SH) armed sea surveillance: (SK) dual trainer.

Engine: One Svenska Flygmotor RM8 (licence-built Pratt & Whitney JT8D two-shaft turbofan redesigned in Sweden for Mach 2 and fitted with SFA afterburner): (AJ. SF, SH and Sk) 25,9701b (11,790kg) RM8A: (JA) 28,086lb (12,750kg) RM8B.

Dimensions: Span of main wing 34ft 9^in (10’6m): length (AJ) 53ft 5jin (1 6-3m): (JA37 with probe) 53ft 11 in: height 18ft 4J-in (5-6m).

Weights: Not disclosed, except AJ37 "normal armament" gross weight of 35.275lb (16,000kg).

Performance: Maximum speed (clean) about 1,320mph (2135km/h, Mach 2), or Mach 1 -1 at sea level: initial climb, about 40,000ft (12,200m)/ min (time from start of take-off run to 32,800ft—10,000m. = 100sec): service ceiling, over 60,000ft (18,300m): tactical radius with external stores (not drop tanks), hi-lo-hi profile, over 620 miles (1000km).

Armament: Seven pylons (option: nine) for aggregate external load of 13,2001b (6000kg), including Rb04E or Rb05A missiles for attack, and Rb27, Rb28 and Rb324 missiles for defence. In addition the JA37 has a 30mm Oerlikon KCA gun and will carry "new long – and short-range missiles for air-to-air interception": Skyflash is being evaluated.

History: First flight 8 February 1967: (production AJ) 23 February 1971: service delivery (AJ) June 1971.

User: Sweden (RSAF).

Development: Yet again blazing a trail ahead of other nations, the Royal Swedish Air Board planned System 37 in 1958—61 as a standardized weapon system to be integrated with the Stril 60 air-defence environment of radars, computers and displays. Included in the system is a standard platform (in this case a supersonic manned aircraft) produced in five

versions each tailored to a specific task. Thanks to a unique configuration with a 400 sq ft wing preceded by a canard foreplane with trailing-edge flaps, the Viggen (Thunderbolt) has outstanding STOL (short take-off and landing) performance and excellent turn radius at all speeds. Efficient and prolonged operations are possible from narrow strips 500m (1,640ft) in length, such as stretches of highway. Equipment in all versions includes headup display, autothrottle/speed control on approach, no-flare landing autopilot and thrust reverser. The AJ operates camouflaged in attack wings F7, F15 and F6. with production continuing in 1 977 on a mix of AJ, SF. SH ►

proved as outstanding as it looked on paper in the 1960s, and even today no other Western European aircraft can rival it for radar performance, flight performance and short field length in all weathers. The latest Viggen variant, the JA37, is considerably different, with a new engine, very powerful gun. UAP 1023 pulse-doppler radar, digital automatic flight control system and extremely advanced inertial measurement and central computer systems. The development effort for the JA37 rivals that for the complete original aircraft, but with the help of a fleet of special-purpose test aircraft (some new and most rebuilds of early AJ and other models) the JA was cleared for production in 1976. By the start of 1 977 most of the initial batch of 30 were on the line, and service delivery is due in 1978. Eventually 200 are to equip eight squadrons.