Design and development
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
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 57-millimetre (2.2 in) automatkanon m/47 autocannon 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]
Saab AB, with subsidiaries collectively known as the Saab Group, is a Swedish aerospace and defense company primarily operating from Sweden. The company is headquartered in Stockholm, but its development and manufacturing operations are undertaken in Linköping.
The Messerschmitt Me 410 Hornisse (Hornet) was a German heavy fighter and Schnellbomber used by the Luftwaffe during World War II. Though an incremental improvement of the Me 210, it had a new wing plan, longer fuselage and engines of greater power. The changes were significant enough for the aircraft to be renamed the Me 410.
The Douglas B-18 Bolo is an American heavy bomber which served with the United States Army Air Corps and the Royal Canadian Air Force during the late 1930s and early 1940s. The Bolo was developed by the Douglas Aircraft Company from their DC-2, to replace the Martin B-10.
The Ilyushin Il-18 is a large turboprop airliner that first flew in 1957 and became one of the best known Soviet aircraft of its era. The Il-18 was one of the world's principal airliners for several decades and was widely exported. Due to the aircraft's durability, many examples achieved over 45,000 flight hours and the type remains operational in both military and civilian capacities. The Il-18's successor was the longer-range Ilyushin Il-62.
The Saab 35 Draken is a Swedish fighter-interceptor developed and manufactured by Svenska Aeroplan Aktiebolaget (SAAB) between 1955 and 1974. Development of the Saab 35 Draken started in 1948 as the Swedish air force future replacement for the then also in development Saab 29 Tunnan dayfighter and Saab 32B Lansen night fighter. It featured an innovative but unproven double delta wing, which led to the creation of a sub-scale test aircraft, the Saab 210, which was produced and flown to test this previously-unexplored aerodynamic feature. The full-scale production version entered service with frontline squadrons of the Swedish Air Force on 8 March 1960. It received the designation Flygplan 35 and was produced in several variants and types, most commonly as a fighter type with the prefix J, standing for Jaktflygplan (Pursuit-aircraft), the Swedish term for fighter aircraft.
R4M, abbreviation for Rakete, 4 kilogramm, Minenkopf, also known by the nickname Orkan due to its distinctive smoke trail when fired, was a folding-fin air-to-air rocket used by the Luftwaffe at the end of World War II.
The Ruhrstahl Ru 344 X-4 or Ruhrstahl-Kramer RK 344 was a wire-guided air-to-air missile designed by Germany during World War II. The X-4 did not see operational service and thus was not proven in combat but inspired considerable post-war work around the world, and was the basis for the development of several ground-launched anti-tank missiles.
The Henschel Hs 132 was a World War II dive bomber and interceptor aircraft of the German Luftwaffe that never saw service. The unorthodox design featured a top-mounted BMW 003 jet engine and the pilot in a prone position. The Soviet Army occupied the factory just as the Hs 132 V1 was nearing flight testing, the V2 and V3 being 80% and 75% completed.
The Saab 29 Tunnan, colloquially also Flygande Tunnan, is an early jet-powered fighter aircraft designed and produced by the Swedish aircraft manufacturer Saab. It was the second turbojet-powered combat aircraft to be developed in Sweden, the first being the Saab 21R, and it was the first Western European fighter to be produced with a swept wing after the Second World War, only being preceded in Western Europe as a whole by the Messerschmitt Me 262 built during the conflict.
The Royal Small Arms Factory ADEN cannon is a 30 mm revolver cannon used on many military aircraft, particularly those of the British Royal Air Force and Fleet Air Arm. Developed post-World War II primarily to meet British Air Ministry's requirement for increased lethality in aircraft armament, the cannon was fired electrically and is fully automatic once it is loaded.
The Saab 17 is a Swedish single-engine monoplane reconnaissance dive-bomber aircraft of the 1940s originally developed by ASJA prior to its merger into Saab. It was the first all-metal stressed skin aircraft developed in Sweden.
The HS.404 is an autocannon originally designed by and produced by the Swiss arm of the Spanish/Swiss company Hispano-Suiza in the mid-1930s. Production was later moved to the French arm of Hispano Suiza.
The RP-3 was a British air to ground rocket projectile introduced during the Second World War. The "3 inch" designation referred to the nominal diameter of the rocket motor tube. The use of a 60 lb (27 kg) warhead gave rise to the alternative name of the "60-pound rocket". Though an air-to-ground weapon, it saw limited use in other roles. They were generally used by British fighter-bomber aircraft against targets such as tanks, trains, motor transport and buildings, as well as by Coastal Command and Royal Navy aircraft against U-boats and ships.
The Fokker G.I was a Dutch twin-engined heavy fighter aircraft comparable in size and role to the German Messerschmitt Bf 110. Although in production prior to World War II, its combat introduction came at a time the Netherlands were overrun by the Germans. The few G.Is that were mustered into service were able to score several victories. Some were captured intact after the Germans had occupied the Netherlands. The remainder of the production run was taken over by the Luftwaffe for use as trainers.
The Saab 21R was a Swedish fighter/attack aircraft developed and produced by Svenska Aeroplan AB (SAAB). It was a jet-powered development of the piston-engined SAAB 21 and was the first jet aircraft to be produced by Saab. The R-suffix stands for reaktion (reaction), referencing reaktionsdrift or reaktionsmotor. Along with the Soviet Yakovlev Yak-15, the 21R was one of only two jet fighters to have been successfully converted from piston-powered aircraft.
The SAAB 21 is a Swedish single-seat low-wing monoplane fighter and attack aircraft designed and manufactured by SAAB. It used a relatively unorthodox twin boom fuselage with a pusher engine, giving the aircraft an unusual appearance.
The Sukhoi Su-6 was a Soviet ground-attack aircraft developed during World War II. The mixed-power high-altitude interceptor Su-7 was based on the single-seat Su-6 prototype.
The Caproni Ca.313 was an Italian twin-engine reconnaissance bomber of the late-1930s. It was a development of the Ca.310. Its variants were exported to several other countries.
This is a list of weapons used by the Swedish Air Force.
The Bofors 57 mm m/47 aircraft gun was a Swedish aircraft gun developed by Bofors AB for the T 18B, a Swedish torpedo bomber manufactured by SAAB. The designation "57 mm automatkanon m/47" is translated to "57 mm autocannon model 1947". It is referred to as the Bofors 57 mm type L50 by the manufacturer.
