Saab 18

Svenska Aeroplan AB (SAAB)

Industry	Aerospace, Defense
Founded	1937
Headquarters	Linköping , Sweden
Products	Aircraft (including Saab 18)

The Saab 18 was a twin-engine aircraft developed by Svenska Aeroplan AB (SAAB) to fulfill a 1938 Swedish Air Force competition requirement. Designed as both a bomber and reconnaissance platform, its entry into service was delayed until 1944. Despite this, it rapidly became the principal bomber in Sweden’s aerial arsenal. The Saab 18 fulfilled multiple roles including bombing, reconnaissance, and ground attack, and played a significant part in advancing technologies such as ejection seats and air-to-surface guided missile systems before being superseded by the Saab Lansen in the late 1950s.

Design and development

The Saab 18 was conceived to replace the Junkers Ju 86 within the Swedish Air Force, based on a requirement for a fast three-seat reconnaissance aircraft. Several companies, including AB Svenska Järnvägsverkstädernas Aeroplanavdelning (ASJA), SAAB, and AB Götaverken (GV), submitted proposals. Although GV’s GV8 design initially seemed most suitable, its high cost coupled with the departure of their lead designer led to SAAB—by then merged with ASJA—being awarded the development contract.

With American engineers on SAAB’s design team, the Saab 18 exhibited design elements reminiscent of U.S. aircraft. The onset of World War II shifted Swedish Air Force priorities, accelerating production of the Saab 17 and delaying progress on the Saab 18. Additionally, evolving requirements added a medium bomber role to the original specification, postponing the first flight until 19 June 1942.

The prototype featured a mid-wing monoplane layout with twin vertical stabilizers, powered by two Pratt & Whitney R-1830 Twin Wasp radial engines. Its crew consisted of three members: a pilot and navigator seated beneath an offset glazed canopy, and a bombardier positioned in the nose section. Armament included three 13.2-millimetre (0.52 in) machine guns—one fixed forward-firing operated by the pilot and two flexible mounts controlled by the navigator and bombardier for defensive purposes. The aircraft could internally carry up to 1,000 kilograms (2,200 lb) of bombs in its bomb bay, complemented by up to eight 50-kilogram (110 lb) bombs mounted on underwing pylons.

Flight trials revealed that the powerplants were insufficient for optimal performance. Nevertheless, due to the lack of available higher-powered engines at that time, production proceeded with both bomber (B 18A) and reconnaissance (S 18A) variants ordered into service.

Operational history

The B 18A was introduced into operational use in June 1944 and rapidly became Sweden's primary medium bomber. With the availability of license-produced Daimler-Benz DB 605 liquid-cooled V-12 engines, these powerplants were integrated into the enhanced Saab 18B model, which conducted its maiden flight on 10 July 1944.

Initially produced as the B 18B dive bomber, this variant evolved into the T 18B, intended to serve as a torpedo bomber version. However, complications with torpedo deployment led to the T 18B being repurposed into a robust ground-attack aircraft, equipped with a 57-millimetre (2.2 in) automatkanon m/47 autocannon mounted beneath the nose section.

By the late 1940s, the crew was reduced from three to two members as advancements such as air-to-ground rocket armaments and enhanced bombsight technology eliminated the need for a dedicated bombardier. Around this period, the Saab 18 earned a reputation for relatively high loss rates, prompting a decision to retrofit all remaining aircraft with ejection seats for both pilot and navigator/gunner roles.

A total of 245 Saab 18 units were manufactured, with production of the final T 18B completed in 1948. The aircraft participated in tests involving early Swedish air-to-surface missile technologies, maintaining its role as a frontline ground attack and reconnaissance platform through most of the 1950s. Eventually, it was supplanted by the jet-powered, swept wing Saab 32 Lansen, with B 18B and T 18B models replaced by the A 32A in 1958, and the last S 18A reconnaissance versions phased out in favor of S 32Cs in 1959.

Variants

File:ASJA L-11 (P-8A).jpg

Three-quarter view of the ASJA L 11

Saab 18

Prototype B 18A powered by SFA STWC-3 engines. This same prototype was later refitted with SFA DB 605B engines, serving as the basis for the B 18B model.

B 18A

The initial production bomber variant powered by twin SFA STWC-3 Twin Wasp radial piston engines. Armament consisted of three 13.2 mm akan m/39A autocannons—one fixed forward-firing and two movable defensive guns. A total of 62 units were built. Early in service, bomb forks were added to enable dive bombing capabilities. Between 1946 and 1947, all B 18As were converted into S 18A reconnaissance aircraft.

S 18A

A photo-reconnaissance adaptation of the B 18A, equipped with PS-18/A radar and various other modifications.

B 18B

This dive bomber variant was powered by two Daimler-Benz DB 605B piston engines. Initially armed with three autocannons identical to those on the B 18A, it was soon reduced to two due to limited utility of the lower defensive gun caused by restricted traverse and poor gunner visibility. Starting in 1946, it participated in Sweden’s rocket development program, testing various rocket types. By 1949–1950, all B 18Bs were redesignated as attack aircraft and outfitted to carry either twelve light rockets or a combination of eight light and two heavy rockets. During this upgrade phase, ejection seats were installed for both pilot and radio operator; consequently, the bombardier role was removed and the radio operator’s defensive gun was eliminated—rendered obsolete in the jet age. Many aircraft also received a new rounded windshield design at this time. Toward the end of their service lives, B 18Bs were utilized effectively for reconnaissance missions, primarily deploying flare bombs and equipped with PS-18/A radar similar to that on the S 18A. A total of 119 units were produced.

T 18B

An attack aircraft originally intended as a torpedo bomber variant but repurposed due to torpedo deployment challenges. Powered by the same engines as the B 18B, it retained similar fixed and upper defensive autocannons but added two fixed 20 mm akan m/41 guns mounted in the nose. The enlarged bomb bay—initially designed for torpedoes—could accommodate either a single 1,000 kilograms (2,200 lb) m/47 medium-capacity/general-purpose bomb or a 57 mm akan m/47 autocannon with forty-one rounds alongside standard bomb loads from the B 18B. Early in its service life, it was also tested with RB 302 anti-shipping missiles that never entered operational use. In 1949, it received rocket armament upgrades and ejection seats similar to those fitted on B 18Bs but could carry only eight light rockets. That same year featured trials equipping twin Bofors L70s replacing its standard autocannon; however, recoil damage to nose glazing terminated these tests prematurely. Fifty-two T 18Bs were built.

B 18A Dubbelkommando

A trainer modification where the radio operator’s seat was reversed to face an instructor's position. Although an armored partition between seats limited instructor visibility, this conversion was deemed beneficial since no new trainer aircraft had to be procured and reconversion for combat duties remained straightforward.

B 18B Dubbelkommando

Trainer adaptation following the same concept applied to the B 18B model.

Proposed Variants and Unused Nomenclature

• ASJA L 11 (P8A) - An early design concept from ASJA dated April 1939, featuring a nose wheel and lacking planned bomb racks on the wings.
• S 18B - Initially intended as a reconnaissance aircraft since the B 18A had just been introduced. However, its outstanding capabilities led to a role reversal, designating the B 18A as the reconnaissance model instead.
• A 18B - A designation that was never employed, originally reserved for the B 18B when it was officially classified as an attacker.
• T 18 - The initial blueprint for the T 18B, which was proposed to be developed based on the B 18A platform.
• T 18C - The originally intended designation for what became the T 18B.
• T 18B-1 - Planned identifier for T 18B variants outfitted specifically for torpedo bombing missions.
• T 18B-2 - Designation planned for T 18B models equipped with a 57 mm armament.
• BJ 18B - A projected night fighter version armed with a gun pod or turret housing four 20 mm akan m/45 autocannons, each with 180 rounds. There were also proposals to power it with either 2,000 hp (1,500 kW) Double Wasp engines or to enhance DB 605B engines by using 100 octane fuel for increased output. This concept was shelved in favor of prioritizing T 18B development.
• J 18C - An alternative suggested designation for the night fighter variant.
• B 18R - A jet-powered concept fitted with STAL jet engines. The project progressed significantly, selecting an airframe for prototype conversion in 1945; however, it was ultimately abandoned due to focus shifting to T 18B development.

Operators

Template:SWE

• Swedish Air Force

Surviving Aircraft

File:Saab B18B 18172 D red (8292047964).jpg

Saab B 18B exhibited at the Swedish Air Force Museum

At present, only one Saab 18 remains extant: a B 18B model bearing the code Red David. This aircraft is preserved within the collection of the Flygvapenmuseum (Swedish Air Force Museum) located near Linköping, Sweden. It was among eight aircraft lost during a snowstorm in 1946 but was later recovered and underwent restoration in 1979.

There is speculation that another aircraft from this group remains undiscovered. One plane lost in the same snowstorm has yet to be located. Recent aerial imagery released by Swedish meteorological researchers has generated new hypotheses regarding its crash site. The aircraft, identified as Red Niklas, is believed to be well preserved if situated at the proposed location. The Swedish Air Force has expressed interest in this discovery because the fate of its three crew members remains unresolved and they have not been interred.

Technical Specifications (B 18B)

Armament gallery

• Bomb bay equipped with 500 kg bombs and bomb forks
  Bomb bay equipped with 500 kg bombs and bomb forks
• Bomb bay loaded with 250 kg bombs
  Bomb bay loaded with 250 kg bombs
• Bomb bay containing 50 kg bombs
  Bomb bay containing 50 kg bombs
• Wing-mounted 50 kg bombs
  Wing-mounted 50 kg bombs

• B 18B rocket launchers (identical wing mounts used on the T 18B)
  B 18B rocket launchers (identical wing mounts used on the T 18B)
• Signal operator’s akan m/39A autocannon; the magazine elevates as the weapon fires to ensure proper feeding
  Signal operator’s akan m/39A autocannon; the magazine elevates as the weapon fires to ensure proper feeding
• Observer’s 13.2 mm akan m/39 on the B 18A and early B 18B variants
  Observer’s 13.2 mm akan m/39 on the B 18A and early B 18B variants
• T 18B featuring the 57 mm akan m/47
  T 18B featuring the 57 mm akan m/47

Bibliography

• Donald, David, editor. 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., editor. Das große Flugzeug-Typenbuch. Stuttgart: Transpress. 1987, ISBN 3-344-00162-0.

External links

• "Sweden, 1936-1996". ejection-history.org
• "B 18 - Saab 18 (1944-1959)"
• Video footage showing a Saab 18 during takeoff and flight, from the Swedish Air Force Museum’s YouTube channel