Design work on Aircraft 18 was commenced at the beginning of 1939 to meet an official Swedish requirement for a reconnaissance aircraft. The Air Force chiefs had announced a competition for the design of a twin-engined aircraft to replace the old B3. The competi-tion was won by Saab.
A cantilever mid-wing monoplane, primarily of metal construction, the Saab-18 had retractable tailwheel landing gear, a twin-fin-and-rudder tail unit, and was powered as first flown by two 794kW Swedish-built Pratt & Whitney R-1830 Twin Wasp radial engines in wing-mounted nacelles. The crew comprised a pilot, navigator/gunner and bomb-aimer, the last having a position in the glazed nose of the fuselage.
The first prototype took to the air on 19 June 1942. As a result of changing requirements, the two Saab-18A prototypes were redesigned and equipped for the light bomber or dive-bomber role. Early testing of the prototypes revealed that the Saab-18A was underpowered, but with no immediate remedy available.
The type was ordered into production in B18A bomber and S18A photo-reconnaissance versions, built to a combined total of 60 aircraft; late production examples of the S18A also carried radar equipment. Delivered to Bomber Wing Fl in June 1944, the aircraft was designated the B18. Several B18s were con-verted for reconnaissance duties with the in-stallation of radar and camera equipment. This version became known as the B18A.
The availability in 1944 of a Swedish licence-built version of the much more powerful Daimler-Benz DB 605B powerplant led to the single Saab-18B prototype, first flown on 10 June 1944 and followed by 120 B18B dive-bomber production aircraft. With new engines, this version was one of the fast-est piston-engined aircraft in the world, reaching a top speed of 570 km/h (354 mph).
Final production version was the T18B (62 built) which had been developed to serve as a torpedo-bomber but was, instead, completed as an attack aircraft. With a crew of two, this could ei-ther be fitted with torpedoes for anti-shipping duties or armed with a single 157-mm and two 20-mm automatic Bofors cannons. Production of the last T18B ended in 1948.
242 production aircraft serviced until the last of them was retired in 1956.
B/S18A Span: 17.04 m (55 ft 10.75 in) Length: 13.23 m (43 ft 4,75 in) Take-off weight: 8700 kg (1918 lb) Maximum speed: 465 kph (289 mph) Cruising speed: 415 kph (258 mph) Landing speed: 135 kph (84 mph) Range: 2200 km (1367 miles) Max. altitude: 8000 m (26250 ft)
B18B Engines: 2 x Daimler-Benz DB 605B, 1100kW Span: 17.04 m (55 ft 10.75 in) Length: 13.23 m (43 ft 4,75 in) Height: 4.35 m / 14 ft 3 in Wing area: 43.75 sq.m / 470.92 sq ft Take-off weight: 8793 kg (1938 lb) Maximum speed: 570 kph (354mph) Cruising speed: 480 kph (298 mph) Landing speed: 125 kph (78 mph) Ceiling: 9800 m / 32150 ft Range: 2600 km (1616 mph) Max. altitude: 9800 m (32150 ft) Armament: 1 x 7.9mm and 2 x 13.2mm machine-guns Bombload: 1500kg
T18B Span: 17.04 m (55 ft 10.75 in) Length: 13.23 m (43 ft 4,75 in) Take-off weight, kg (lb) 9272 kg (2044 lb) Maximum speed: 595 kph (370 mph) Cruising speed: 480 kph (298 mph) Landing speed: 130 kph (81 mph) Range: 2600 km (1616 miles) Max. altitude: 9300 m (30150 ft)