The Saab 18 was a twin-engine

bomber A bomber is a military combat aircraft designed to attack ground and naval targets by dropping air-to-ground weaponry (such as bombs), launching aerial torpedo, torpedoes, or deploying air-launched cruise missiles. The first use of bombs dropped ...

and

reconnaissance aircraft A reconnaissance aircraft (colloquially, a spy plane) is a military aircraft designed or adapted to perform aerial reconnaissance with roles including collection of imagery intelligence (including using photography), signals intelligence, as ...

, designed and built by Svenska Aeroplan AB (SAAB) for use by the

Swedish Air Force The Swedish Air Force ( sv, Svenska flygvapnet or just ) is the air force branch of the Swedish Armed Forces. History The Swedish Air Force was created on 1 July, 1926 when the aircraft units of the Army and Navy were merged. Because of the es ...

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 seat In aircraft, an ejection seat or ejector seat is a system designed to rescue the aircraft pilot, pilot or other aircrew, crew of an aircraft (usually military) in an emergency. In most designs, the seat is propelled out of the aircraft by an ex ...

s and air-to-surface

guided missile In military terminology, a missile is a guided airborne ranged weapon capable of self-propelled flight usually by a jet engine or rocket motor. Missiles are thus also called guided missiles or guided rockets (when a previously unguided rocket ...

s until its replacement by the Saab Lansen in the late 1950s.

Design and development

Intended as a replacement for the

Junkers Ju 86 The Junkers Ju 86 was a German monoplane bomber and civilian airliner designed in the early 1930s, and employed by various air forces on both sides during World War II. The civilian model Ju 86B could carry ten passengers. Two were delivered to S ...

in service with the Swedish Air Force,Fredriksson, Urban. (2005
"Saab 18"
''Swedish Military Aviation''. Accessed 2010-05-17. the requirement that led to the Saab 18 called for a three-seat fast reconnaissance aircraft.Donald 1997, p. 809. AB Svenska Järnvägsverkstädernas Aeroplanavdelning (ASJA), SAAB, and AB Götaverken (GV) submitted designs for consideration by the Swedish Air Force. 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. As a number of Americans were on the design staff of SAAB and ASJA, the Saab 18's design shared some similarities with American designs. The outbreak of

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

in 1939 led to a change of priorities by the Swedish Air Force, and production of the

Saab 17 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. Design and de ...

was accelerated, at the expense of work on the Saab 18, which, along with a change of requirements that added the role of medium

to the specification, resulted in the first flight of the aircraft being delayed until 19 June 1942. Manned by a crew of three — a pilot and navigator under a glazed, offset canopy, and a bombardier in the nose — the Saab 18 prototype was a mid-wing monoplane with twin

vertical stabiliser A vertical stabilizer or tail fin is the static part of the vertical tail of an aircraft. The term is commonly applied to the assembly of both this fixed surface and one or more movable rudders hinged to it. Their role is to provide control, sta ...

s, and was powered by two Pratt & Whitney R-1830 Twin Wasp

radial engines The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is cal ...

. Armament consisted of three 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. Up to of

bombs A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechanic ...

could be carried in an internal bay, while up to eight bombs could be carried on underwing hardpoints. Flight testing showed that the aircraft was underpowered. 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.

Operational history

The B 18A entered service in June 1944, and quickly became Sweden's standard medium bomber aircraft. As license-built

Daimler-Benz DB 605 The Daimler-Benz DB 605 is a German aircraft engine built during World War II. Developed from the DB 601, the DB 605 was used from 1942 to 1945 in the Messerschmitt Bf 109 fighter, and the Bf 110 and Me 210C heavy fighters. The DB 610, a p ...

liquid-cooled, inline engines had become available, they were incorporated into the improved Saab 18B, which first flew on 10 July 1944. Ordered into production as the B 18B

dive bomber A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target simplifies the bomb's trajectory and allows the pilot to keep visual contact througho ...

, the 18B design was further developed into the T 18B, which was planned to be a

torpedo bomber A torpedo bomber is a military aircraft designed primarily to attack ships with aerial torpedoes. Torpedo bombers came into existence just before the First World War almost as soon as aircraft were built that were capable of carrying the weight ...

variant. Due to difficulties with the torpedoes, however, the T 18B was instead developed into a heavy ground-attack aircraft, mounting a automatkanon m/47

autocannon An autocannon, automatic cannon or machine cannon is a fully automatic gun that is capable of rapid-firing large-caliber ( or more) armour-piercing, explosive or incendiary shells, as opposed to the smaller-caliber kinetic projectiles (bull ...

under the nose. 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

bombsight A bombsight is a device used by military aircraft to drop bombs accurately. Bombsights, a feature of combat aircraft since World War I, were first found on purpose-designed bomber aircraft and then moved to fighter-bombers and modern tactical ...

s 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

s for the pilot and navigator/gunner. Production of the Saab 18 totaled 245 examples, with the last T 18B being delivered in 1948. Used in trials of early Swedish air-to-surface missiles, 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 A swept wing is a wing that angles either backward or occasionally forward from its root rather than in a straight sideways direction. Swept wings have been flown since the pioneer days of aviation. Wing sweep at high speeds was first investigate ...

Saab 32 Lansen The Saab 32 Lansen (English: Lance) is a two-seat, transonic military aircraft designed and manufactured by Saab AB from 1955 to 1960 for the Swedish Air Force (''Flygvapnet''). Three principal variants of the Lansen were built for attack (A 32A ...

, the B 18B and T 18B being replaced by the A 32A in 1958, with the last S 18As being replaced by S 32Cs in 1959.

Variants

;Saab 18 :One SFA STWC-3 engined B 18A prototype. The same prototype was later re-engined with SFA DB 605B engines as the prototype for the B 18B. ;B 18A :The first production version, bomber aircraft powered by two SFA STWC-3 Twin Wasp radial piston engines and armed with three 13.2 mm akan m/39A autocannons, one fixed, two movable for defence. 62 built. The B 18A was quickly into its service life equipped with bomb forks to be able to dive bomb. All were converted into S 18A reconnaissance planes in 1946-47. ;S 18A :Photo-reconnaissance conversion of B 18A, fitted with PS-18/A radar among other modifications. ;B 18B :Dive bomber version, powered by two

B piston engines. It was at the start armed with the same 3 autocannons as the B 18A but it was quickly downgraded to 2 due to the lower defensive one being borderline useless due its limited traverse and the limited view for the gunner. In 1946 the Swedish rocket-development program started and the B 18B was one of the planes used to test rockets of different types. In 1949-1950 all planes were redesignated as attack aircraft and got the ability to equip 12 light rockets or 8 light rockets and 2 heavy rockets. During the same period they also got

s for the pilot and radio operator. Due to this the bombardier had to be removed and the radio operator lost his defensive gun. The defensive gun had become obsolete either way due to the jet era. Many of the planes that received ejection seats were also modified with a new rounded windshield. Very late into its service life it was used effectively as a reconnaissance plane where it mainly dropped flare bombs and got the same PS-18/A radar as the S 18A. 119 built. ;T 18B :Attack version (originally projected as a torpedo-bomber), powered by the same engines as the B 18B. It was armed with the same fixed and upper defensive autocannon as the B 18B, but had 2 20 mm akan m/41 guns fixed in the nose. It had a bigger bomb bay originally designed for a torpedo, but the aircraft could equip a 1000 kg m/47 medium-capacity/general-purpose bomb or a 57 mm akan m/47 autocannon with 41 rounds instead, besides the original bomb loadouts of the B 18B. Early into its service it was also tested with the RB 302 anti-shipping missile which never entered service. In 1949 it received the same rocket and ejection seat upgrades as the B 18B, but could only carry 8 light rockets. In 1949 it was also tested with twin Bofors 40 mm L70's in place of its iconic 57 mm but the recoil shattered the nose glass, ending the tests. 52 built. ;B 18A Dubbelkommando :Trainer version where the radio operator seat was turned around for an instructor. The armored shield between the seats blocked the instructor's view, but the conversion was considered worth it in the end as no new trainers had to be purchased and the plane could easily be reconverted for combat duty. ;B 18B Dubbelkommando :Same idea as mentioned above but implemented on the B 18B.

Planned variants and unused designations

*ASJA L 11 (P8A) - Early concept art by asja from April 1939. Had a nose wheel and no planned bomb mountings on the wings. *S 18B - The S 18B was originally planned to be a reconnaissance plane due to the B 18A just entering service. Due to its excellent performance it was decided to switch the roles and make the B 18A the recon plane. *A 18B - Unused designation for the B 18B when it became an official attacker. *T 18 - Original plan for the T 18B. It was originally suggested to be built on the B 18A basis. *T 18C - Original planned designation for the T 18B. *T 18B-1 - Planned designation for T 18B's equipped for torpedo bombing. *T 18B-2 - Planned designation for T 18B's equipped with the 57 mm. *BJ 18B - Planned night fighter variant armed with a gunpod/tub with 4x 20 mm akan m/45 autocannons with 180rpg. It was also suggested to equip it with Double Wasp engines or to run the DB 605B engines on 100 octane fuel to increase their power. The plan was never followed through due to the development of the T 18B taking priority. *J 18C - Other suggested designation for the night fighter version. *B 18R - Suggested jet variant equipped with STAL jet engines. The project came fairly far and an airframe was selected to be converted into the prototype in 1945. The plan was never followed through due to the development of the T 18B taking priority.

Operators

; *

Survivors

Only a single example of the Saab 18 survives today: a B 18B, coded ''Red David''. It is part of the collection of the ''Flygvapenmuseum'', the Swedish Air Force Museum near

Linköping Linköping () is a city in southern Sweden, with around 105,000 inhabitants as of 2021. It is the seat of Linköping Municipality and the capital of Östergötland County. Linköping is also the episcopal see of the Diocese of Linköping (Church ...

in Sweden. One of a group of eight aircraft lost in a snowstorm in 1946, it was recovered and restored in 1979. Another plane is believed to have survived. One aircraft from the same group that got lost in the snowstorm mentioned above was never found. A new theory of where it crashed has surfaced due to new aerial photos being released by Swedish weather and climate researchers. The plane was coded ''Red Niklas'' and according to theory it should be well preserved if it lies on the believed crash site. The Swedish air force has shown interest in the matter due to the plane's three crew members never being found nor buried.

Specifications (B 18B)

Armament gallery

File:Saab B 18 bombgafflar.png, Bomb bay with 500 kg bombs (+ bomb forks) File:Saab B 18 250 kg bomber.png, Bomb bay with 250 kg bombs File:Saab B 18 50 kg bomber.png, Bomb bay with 50 kg bombs File:Saab B 18 50 kg bomber vingar.png, Wings with 50 kg bombs File:Saab 18 rockets english.png, The rocket ramps of the B 18B. (The T 18B used the same wing ramps) File:Saab 18 signalistkanon.jpg, The signalist's akan m/39A autocannon. The

magazine A magazine is a periodical publication, generally published on a regular schedule (often weekly or monthly), containing a variety of content. They are generally financed by advertising, purchase price, prepaid subscriptions, or by a combinatio ...

moves up as the gun shots to feed properly File:Saab B 18 signalist akan.png, The obsever's 13.2 mm akan m/39 on B 18A and early B 18B File:Saab T 18B kanon.png, T 18B with the 57 mm akan m/47

Citations

Bibliography

* * Donald, David, ed. ''The Complete Encyclopedia of World Aircraft''. London: Orbis, 1997. . * Eliasson, Gunnar. ''Advanced Public Procurement as Industrial Policy: The Aircraft Industry as a Technical University''. Springer, 2010. . * Frawley, Gerard and Jim Thorn. ''International Directory of Military Aircraft, 1996/97''. Motorbooks International, 1996. . * Kopenhagen, W. (ed.) ''Das große Flugzeug-Typenbuch.'' Stuttgart: Transpress. 1987, .

External links

"Sweden, 1936-1996"
''ejection-history.org''

Movie footage
of a Saab 18 taking off and in-flight, the Swedish Air Force Museum's YouTube channel {{Authority control 18 1940s Swedish bomber aircraft Mid-wing aircraft Aircraft first flown in 1942 Twin piston-engined tractor aircraft Twin-tail aircraft