Conceived toward the
end of 1939 as a reconnaissance plane, the Saab 18 was characterized by
a long completion period. It did not enter into service in the Swedish
Flygvapnet as a bomber until the summer of 1944 (it remained until
1956). Production continued well beyond the end of World War II (the
assembly lines did not close until 1948) and 242 aircraft were
completed in three versions, the last of which (T18B) was built for
The project (originally
designated L-11) originated from a request by the Swedish government,
which ordered two prototypes, one in November 1939 and the other in
February 1940. However, the course of the conflict led to radical
changes in the original specifications. The two experimental aircraft
were in fact developed as light daytime bombers and dive bombers. The
first prototype did not take to the air until June 19, 1942, and
despite the fact that the aircraft appeared to be seriously
underpowered, a month later it went into production in two initial
versions (on the basis of an order for 60 aircraft): the 818A bomber
and the S18A photo reconnaissance plane.
The Saab 18 was a
middle cantilever wing monoplane with metal airframe and retractable
rear tricycle landing gear characterized by an empennage with twin
rudders causing it to resemble the German Dornier Do 217 bomber. It was
powered by a pair of 1,065 hp (794 kW) Pratt & Whitney R-1830 Twin Wasp
radial engines (built on license in Sweden) in wing mounted nacelles.
The defensive armament consisted of a 7.9 mm (0.31 in) calibre fixed
machine gun in the front and another two 13.2 mm (0.52 in) flexible
weapons. The offensive armament consisted of a maximum of 3,311 lbs
(1500 kg) of bombs in the hold. The crew was composed of three members,
the navigator/gunner, bomb-aimer and the pilot who was housed in a
cockpit that was off-centre to the aircraft's longitudinal axis, in
order to improve downward visibility.
The initial production
series aircraft went into service in June 1944, although in the
meantime, due to the building on license of the German Daimler-Benz DB
605B engine, Saab had already prepared a second version of the bomber,
powered by more powerful engines. On 10 June 1944, the B18B took to the
air, showing a marked overall improvement compared to its predecessor.
Consequently, production was authorized on the basis of an order for
120 aircraft and the first B18Bs went into service in 1946.
In the meantime, the
prototype of the final production version, the T18B, developed
initially as a torpedo plane, had made its maiden flight on 7 July
1945. In all, 62 of these aircraft were completed in a structure
suitable for the role of ground attack. The crew was reduced to two
members, while the particularly heavy armament consisted of a pair of
20 mm cannons and a 57 mm Bofors cannon installed in the nose in a pod
beneath the fuselage. The first of the B18A bombers began to enter
service with the Flygvapen in June 1944 and production of the last T18B
ended in 1948, these 242 production aircraft providing valuable service
until the last of them was retired in 1956.
Bomber & Dive Bomber
(Saab 18A) Two 1,065 hp (794 kW) Pratt & Whitney R-1830 Twin Wasp
radial engines (built on license in Sweden). (Saab 18B) Two 1,475 hp
(1100 kW) Daimler-Benz DB 605B inverted Vee piston engines.
Maximum speed 357 mph (575 km/h) at optimum altitude; service ceiling
32,150 ft (9800 m).
miles (2600 km) on internal fuel.
take-off weight of 19,400 lbs (8800 kg).
55 ft 9 1/4 in (17.00 m); length 43 ft 5 in (13.23 m); height 14 ft 3
1/4 in (4.35 m); wing area 470.94 sq ft (43.75 sq m).
fixed forward-firing 7.9 mm (0.31-in) M/22F machine-gun and two 13.2 mm
(0.52 in) machine-guns on trainable mounts, plus an internal bombload
of 3,307 lbs (1500 kg) and provision to carry air-to-air rockets.
(T18B) Two 20 mm cannon and a 57 mm Bofors gun mounted beneath the
B18A (bomber), S18A (reconnaissance), 18B (a single prototype), B18B
(dive-bomber), T18B (attack aircraft).
versions of the Saab S18A did carry radar equipment.
flight (18A) June 1942; First flight (18B) 10 June 1944; entered
service (B18A) June 1944; production ended (T18B) 1948; retired from
service (all versions) 1956.