Saab 18

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SAAB 18
Saab S 18.jpg
SAAB 18, c.1942-1943
Role Bomber/Reconnaissance
Manufacturer Svenska Aeroplan AB
Designer Frid Wänström
Carl Haddon
First flight 19 June 1942
Introduction 1944
Retired 1959
Primary user Swedish Air Force
Produced 1944-1948
Number built 245

The SAAB 18 was a twin-engine bomber and reconnaissance aircraft, designed and built for use by the Swedish Air Force by Svenska Aeroplan AB (SAAB) in response to a 1938 design competition. Due to delays, it did not enter service until 1944, but quickly became the standard Swedish bomber aircraft. Serving in the bomber, reconnaissance and ground-attack roles, it also assisted in the development of ejection seats and air-to-surface guided missiles until its replacement by the Saab Lansen in the late 1950s.

Design and development[edit]

Intended as a replacement for the Junkers Ju 86 in service with the Swedish Air Force,[1] the requirement that led to the Saab 18 called for a three-seat fast reconnaissance aircraft.[2]

AB Svenska Järnvägsverkstädernas Aeroplanavdelning (ASJA), SAAB, and AB Götaverken (GV) submitted designs for consideration by the Swedish Air Force.[1] GV's GV8 appeared to be the best suited to the requirement; however, its cost and the departure of their chief designer resulted in SAAB — the company having merged with ASJA in the meantime — being awarded a contract for development of their design.[1]

As a number of Americans were on the design staff of SAAB and ASJA,[3] the Saab 18's design shared some similarities with American designs.[1] The outbreak of World War II in 1939 led to a change of priorities by the Swedish Air Force, and production of the Saab 17 was accelerated, at the expense of work on the Saab 18,[1] which, along with a change of requirements that added the role of medium bomber to the specification, resulted in the first flight of the aircraft being delayed until 19 June 1942.[2]

Manned by a crew of three — a pilot and navigator under a glazed, offset canopy, and a bombardier in the nose[2] — the Saab 18 prototype was a mid-wing monoplane with twin vertical stabilisers,[2] and was powered by two Pratt & Whitney R-1830 Twin Wasp radial engines.[2] Armament consisted of three 13.2-millimetre (0.52 in) machine guns, one fixed firing forwards and controlled by the pilot, the others being in flexible defensive mounts for use by the navigator and bombardier.[1] Up to 1,000 kilograms (2,200 lb) of bombs could be carried in an internal bay, while up to eight 50-kilogram (110 lb) bombs could be carried on underwing hardpoints.[1]

Flight testing showed that the aircraft was underpowered.[2] However, as there was no immediate prospect for the acquisition of more powerful engines, the Saab 18 was ordered into production in both bomber (B 18A) and reconnaissance (S 18A) versions.[2]

Operational history[edit]

The B 18A entered service in June 1944,[1] and quickly became Sweden's standard medium bomber aircraft.[4] As license-built Daimler-Benz DB 605 liquid-cooled, inline engines had become available, they were incorporated into the improved Saab 18B, which first flew on 10 July 1944.[2]

Ordered into production as the B 18B dive bomber, the 18B design was further developed into the T 18B, which was planned to be a torpedo bomber variant.[2] Due to difficulties with the torpedoes, however,[1] the T 18B was instead developed into a heavy ground-attack aircraft, mounting a Bofors 57-millimetre (2.2 in) cannon under the nose.[2]

By the late 1940s, the third crewmember's position had been eliminated, reducing the crew of the aircraft to two; the provision of air-to-ground rockets and improved bombsights had removed the requirement for a bombardier. By this time the Saab 18 had established a reputation for suffering a serious rate of attrition, and this led to the decision to outfit all of the surviving aircraft with ejection seats for the pilot and navigator/gunner.[5]

Production of the Saab 18 totaled 245 examples,[6] with the last T 18B being delivered in 1948. Used in trials of early Swedish air-to-surface missiles,[1] the Saab 18 remained one of Sweden's frontline ground attack and reconnaissance platforms until the late 1950s, when it was replaced by the jet-powered, swept wing Saab 32 Lansen,[7] the B 18B and T 18B being replaced by the A 32A in 1958,[1] with the last S 18As being replaced by S 32Cs in 1959.[1]

Survivors[edit]

The Saab B 18B at the Swedish Air Force Museum (2012)

Only a single example of the Saab 18 survives today: a B 18B, named Red David. It is parf of the collection of the Flygvapenmuseum, the Swedish Air Force Museum near Linköping in Sweden. One of a group of eight aircraft lost in a snowstorm in 1946, it was recovered and restored in 1979.[8]

Variants[edit]

Saab 18A
Two Pratt & Whitney-powered prototypes.[2]
B 18A
The first production version, bomber aircraft powered by two Pratt & Whitney R-1830 Twin Wasp radial piston engines. 62 built, all converted to S 18A standard 1946-47.[1]
S 18A
Photo-reconnaissance conversion of B 18A, fitted with PS-18/A radar.[1]
Saab 18B
Single Daimler-Benz powered prototype.[2]
B 18B
Dive bomber version, powered by two Daimler-Benz DB 605B piston engines. 119 built; fitted with up to eight air-to-surface rockets in the late 1940s.[1]
T 18B
Projected torpedo-bomber variant; developed as ground attack version. 52 built. Armed with 2 × 20 mm cannons and 1 × 57 mm cannon. Used as testbed for Rb 302 anti-ship missiles.[1]

Operators[edit]

 Sweden

Specifications (B 18B)[edit]

Data from [1][2]

General characteristics

  • Crew: 3 (pilot, navigator/gunner, and bombardier)
  • Length: 13.23 m (43 ft 5 in)
  • Wingspan: 17 m (55 ft 9 in)
  • Height: 4.35 m (14 ft 3 in)
  • Wing area: 43.75 m2 (470.9 sq ft)
  • Empty weight: 6,100 kg (13,448 lb)
  • Max takeoff weight: 8,800 kg (19,401 lb)
  • Fuel capacity: 1,700 litres (370 imp gal; 450 US gal)
  • Powerplant: 2 × Daimler-Benz DB 605 inverted-vee piston engines, 1,100 kW (1,475 hp) each

Performance

  • Maximum speed: 575 km/h (357 mph; 310 kn)
  • Range: 2,600 km (1,616 mi; 1,404 nmi)
  • Service ceiling: 9,800 m (32,152 ft)

Armament

  • Guns: one 7.92mm fixed forwards-firing gun in wing root; two 13.2mm defensive guns.
  • Rockets: 8 air-to-surface rockets on underwing stubs
  • Bombs: 1,500 kilograms (3,300 lb) in internal bay

See also[edit]

Aircraft of comparable role, configuration and era
Related lists

References[edit]

Citations
  1. ^ a b c d e f g h i j k l m n o p q Fredriksson, Urban. (2005) "Saab 18". Swedish Military Aviation. Accessed 2010-05-17.
  2. ^ a b c d e f g h i j k l m Donald 1997, p. 809.
  3. ^ Exxon Air World, Volumes 25, 1972. p. 143.
  4. ^ Flight International volume 52, 1947. p. 284.
  5. ^ Fredriksson, Urban. (1996) "Early Swedish Ejection Seats". Swedish Military Aviation. Accessed 2010-05-17.
  6. ^ Eliasson 2010, p. 79.
  7. ^ Frawley and Thorn 1996, p. 140.
  8. ^ Braunstein, Christian: Svenska Flygvapnets förband och skolor under 1900-talet. (Swedish) Christina von Arbin, 2005. p. 96. ISBN 91-971584-8-8
Bibliography
  • Donald, David, ed. The Complete Encyclopedia of World Aircraft. London: Orbis, 1997. ISBN 0-7607-0592-5.
  • Eliasson, Gunnar. Advanced Public Procurement as Industrial Policy: The Aircraft Industry as a Technical University. Springer, 2010. ISBN 1-4419-5848-7.
  • Frawley, Gerard and Jim Thorn. International Directory of Military Aircraft, 1996/97. Motorbooks International, 1996. ISBN 1-875671-20-X.
  • Kopenhagen, W. (ed.) Das große Flugzeug-Typenbuch. Stuttgart: Transpress. 1987, ISBN 3-344-00162-0.

External links[edit]