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Saab 18

sweden flag Sweden (1944)
Bomber – 245 Built

The Saab 18 is another example of Sweden’s efforts to produce an aircraft to safeguard its neutrality, considering that the same War and international political context prompted the Scandinavian nation to do so. Only that this plane was not devised to keep the skies of Sweden, but rather to protect the national territory from the air. Curiously, when WWII started, the Saab B 17 was given priority at the earlier stages of the war, as a dive bomber was considered more necessary than a light/medium bomber. This plane gave also important contributions to the development of the Swedish aeronautic and military industry, contributing in the development of ejection seats and of air-to-surface (or AGM) missiles; more specifically, anti-ship missiles. Despite being required to maintain Sweden’s neutrality and protect its territory, it entered in service in 1944, quite late to address the threat from Germany but ready to address the threat from the East and to serve at the early days of the Cold War, with distinction. It became also the standard bomber of the Flygvapnet.

The Saab B 18 is a light bomber and reconnaissance plane with three seats, two engines and a double tail, with a design similar to that of the Junkers Ju 86 and the Dornier Do 17 with the rounded shape of the vertical stabilizers. Or simply the very characteristic shape of double tail and double engine bombers of the era: this is, the cockpit placed at the frontal section of the plane and with the bow being made entirely of glass (normally the place of the bomber), and the cockpit being of a glazed offset type with the pilot and navigator. The wing has a trapezoid shape, being a straight leading edge type with the rear part being instead angled.

The Saab B 18 was initially intended to be powered by British-made Bristol Taurus engines. But it received in the end two types of engines during its career as the Taurus engines weren’t available, powered instead with two Pratt & Whitney R-1830 Twin Wasp radial engines of 1065 hp (the Saab J 21 had priority in receiving the Daimler Benz engines). Posterior versions received new powerplants as the Pratt & Whitney were deemed insufficient, hence receiving 2 Daimler Benz DB 605 of 1475 hp, enabling the plane to reach speeds of up to 570 km/h (357 mph), and making of the B 18 one of the fastest light bombers producing during the war. The powerplant was not the only modification the B 18 suffered during its service with the Flygvapnet, as the initial configuration of armament of 3 x 13,2 mm machine guns was changed to a set of one 7,92mm gun and 2 X 13,2mm machine guns (B 18B). Another re-configuration was the instalment of 2 X 20mm cannons and a 57mm gun (T 18B), along with rockets instead of bombs. Noteworthy to point out that the B 18 could carry up to 1,000 kg of bombs in the compartment and 8 x 50 kg bombs at the wings. As reconnaissance and torpedo-bomber variants were developed (though the last one was never put into service), the versatility and adaptability of the B 18 was made evident, at the point of being the platform for testing the Rb 302 anti-ship missiles. The crew was also modified, as following versions needed only two crewmen as rockets were introduced, suppressing the bomber.

Both versions (B 18B and T 18B) received another modification of armament in the 50’s, as they were fitted with rocket launchers allowing a maximum of 4 rockets on each wing, and even another rocket launcher allowing 2 or 4 rockets under the nose. The bomb sight was also equipped with an automatic reflex sight for rocket firing. This conversion meant that the B18B and the T18B would have increased – and more specialized – attack roles. Also, both the B 18B and the T 18B received ejection seats, maximizing the safety of the crew operating with these air assets. In addition, some B18 B units were fitted with two radars (a radar altimeter PH-10 and a search radar PS-18/A, which was a US Navy AN/APS-4 naval radar) for target designation and identification.

This airplane was purposed at replacing the Junkers Ju 86 in service with the Swedish Air Force back then, basing the requirement for a fast bomber with a crew of three. This was later on changed to a bomber having a crew of 3, a bomb payload of up to 750 kg (1653,46 lb), capable of reaching speeds of 500 km/h (310,68 mph) and to be used as a long-range reconnaissance, torpedo-bomber and heavy fighter. The fact that the B 18 ended in serving with the Flygvapnet was a sheer product of luck, as the competition’s design (the GV8 proposed by the competing AB Götaverken) was capable of meeting the requirements. Yet its costs and the departure of Götaverken’s chief designer resulted in Saab awarding the contract in 1938. As development began, many Americans reportedly took part in the design and development process, resulting in the B 18 having some “American traits” in the design. As a result, the B 18 development had a Swedish and an American chief designer: Frid Wänström and Carl Haddon, respectively.

The development process was delayed by two factors explaining the reasons of the Saab B 18 entering in service relatively late: first, the abovementioned shifting in priorities once the war started, with the Saab B 17 dive bomber receiving priority over the Saab B 18. And second, a change in requirements from a light bomber to a medium bomber, which ended in increasing the development time. The first flight took place in 1942, entering in service in 1944 with two initial versions: the B 18A bomber and the S 18A reconnaissance versions. A torpedo-bomber and later attack plane (T 18B), and a dive bomber (B 18B) were developed, receiving ejection seats.

After WWII and in the wake of the Cold War, the B 18B had a very interesting career, as the increase of the Soviet threat asked for reconnaissance missions; in 1945 and 1946 the B18 B was used to reach the Baltic coast and take pictures of every Soviet vessel, meeting Soviet fighters almost every time.

244 units were produced with the Flygvapnet being the sole operator until 1959, year in which the Saab 32 Lansen replaced the B 18: 62 units of the B 18A, 120 units of the B 18B, and 62 units off the T 18B were built. A single surviving airframe is displayed at the Flygvapenmuseum.

Design

The design of the B 18 is very typical of the pre-WWII double-tail light or medium bombers, having some interesting features despite its conventional sight at first glance. The B 18 is a straight leading edge wing airplane, with the engines placed at the first half of the wings. The fuselage was entirely made of metal, with fabric covering the control surfaces, and having the armor being integrally part of the structure.

The most remarkable areas are the canopy, the bow section, and the rear horizontal stabilizers, connecting the two vertical stabilizers with the main airframe. Regarding the canopy and bow section, the canopy is not placed at the longitudinal middle of the plane as it is normally placed, being instead an offset type at the left side. There, the pilot and the navigator were stationed, with the navigator seat being placed backwards. In addition, the bow section had a glazed tip where the bomber was stationed. Reportedly, such scheme improved the visibility for the pilot. The nose of the T 18B version was slightly modified. And the bow inferior section is not entirely straight, having instead an undernose gondola right before the wing-roots. The landing gear was of classic configuration, with the frontal landing gears retracting into the engine gondolas, while the small rear landing gear was placed at the stern of the bomber, right before the horizontal and vertical stabilizers area. In turn, the horizontal stabilizers are of a ‘butterfly shape’, having at the tips the two horizontal stabilizers; the rudders occupied the whole posterior area of the tails. The shape of the vertical stabilizers is of an isosceles trapezoid.

The wing is a mid-wing (cantilever) leading edge wing, with a shape of a right trapezoid and where the two engines are installed, along with the main fuel tanks. In some versions, there was a gun or a cannon installed at one of the wing-roots. The engines, depending of the version, were either a couple of Pratt & Whitney R-1830 Twin Wasp radial engines or a couple of licensed-built Daimler Benz DB 605 liquid cooled inline V-inverted engines. Depending of the installed engines, the air intake might be located below the engine gondola or above the engine gondola. Normally the earlier versions of the B 18 can be identifying by the intakes placed above the engine gondola. The Daimler Benz engine gave the B 18 a quite remarkable speed for a plane of its type back then, being among the fast ones with speeds of 575 km/h (357 mph). Such speed would provide an advantage for attack and reconnaissance missions. Reportedly, the T 18B version could reach speeds of up to 600 km/h (372,82 mph). The propellers of the B 18 where a three-bladed type.

The armament configuration also varied from version to version. The initial configuration was of 3 x 13,2mm machine guns, one firing forwards at the wing root, another firing also forwards at the nose, and another at the rear. This set was then changed for a set of one wing root 7,62mm machine gun and two 13,2mm guns, and then it was changed for a set of a front-firing 57mm Bofors gun at the undernose gondola and 2 x 20mm guns. The B 18 could carry up to 1,000 kg (2,200 lb) bomb and the bombs compartment and up to 8 x 50 kg (110 lb) bombs at the wings. This type of offensive armament was also changed, as it was first modified to carry a torpedo, which never came to be operational, and then it carried up to eight air-to-surface rockets. The B 18 was also used to test the Rb 302 anti-ship missile. The reconnaissance version was fitted with various cameras to perform its mission, along with a radar.

The B 18 was among the first planes in receiving ejection seats, as its high attrition rate made the Flygvapnet to implement such measure for the sake of the crew’s safety. The fact that it had ejection seats and capacity to carry missiles, along with its speed and un-conventional design, makes the B 18 a very interesting design made by a neutral nation during WWII and the early Cold War.

A Versatile Guardian of the Swedish Land

The B 18, although entering quite late to have a remarkable role in defending Sweden’s neutrality as WWII unfolded, it became a very valuable asset for the Nordic nation at the last stage of the war, when the Soviet Union became stronger and advanced towards the West, with the Cold War highlighting the threat it posed to Sweden. Not only its speed and considerable armament made the B 18 an air asset to be reckoned with, but also its versatility and adaptability, let alone its flexibility. The design allowed the installation of new engines that increased the speed of the B 18, as well as a change of armament while in service, at the point of serving as a test bed for one of the earlier anti-ship missiles, the Rb 302. These modifications allowed the B 18 to become very effective bomber and ground-attack planes, and even to serve as a reconnaissance plane capable of approaching or even penetrating Soviet airspace for its missions, facing quite often the Soviet fighters.

Striking at Speed

One of the characteristics that made the B 18 an airplane to be reckoned with was beyond any doubt its speed, especially after the Daimler Benz 305. The B 18B could reach speed of 570 km/h (357 mph), and the T 18B, the most powerful version in terms of firepower, could reach speeds of up to 600 km/h (372,82 mph). This was an advantage when it came to perform bombing or strike attacks with rockets, as the B 18 could have hit any advancing enemy ground forces formation with hit-and-run tactics or simply by direct strikes with devastating effects. Curiously, the S 18A was the slowest version, with speeds of up to 465 km/h being the maximum speed; this can be explained by the fact it was powered by the previous Pratt & Whitney engines, as the S 18A was a direct modification from the B 18A, which was (under)powered by such engines. Nevertheless, as the powerplants were enhanced, the B 18 became a very fast medium bomber. And it could have posed a serious threat to naval surface units approaching the Swedish coast.

Variants of the Saab B 18

  • 18A – Two prototypes powered by Pratt & Whitney R-1830 Twin Wasp engines of 1065 hp.
  • B 18A – This version became the first series version of the B 18, powered with the abovementioned Pratt & Whitney engines. Armed with 3 x 13,2 mm machine guns and up to 1400 kg (3086.47 lbs). 55 units were reportedly converted into the S 18A reconnaissance version in 146-47. 62 units delivered.
  • S 18A – A modified version of the B 18A for reconnaissance purposes, replacing the Caproni Ca 313 (S16) reconnaissance plane in service back then. It was fitted with a varied array of cameras: 3 high-altitude 10/92 and 5/25 cm cameras, 1 panoramic 10/105 cm camera and a 13/30 cm night camera. This version was also fitted with a PS-18A (An American-made AN/APS-4) maritime surveillance radar, with 36 units having this radar installed in pods under the nose, and serving as maritime reconnaissance airplanes.
  • Saab 18B – A single prototype powered with the Daimler Benz DB 605B.
  • B 18B – A dive bomber version powered by the new Daimler Benz DB 605B of 1475 hp engines. It was later on modified to carry up to 8 air-to-surface rockets, becoming an attack plane. Armed with a 13 mm machine gun and a 20 mm gun plus the 1400 kg (3086.47 lbs) payload of bombs, and later on the 8 air-to-surface rockets. A dive bomb sight m/42 developed by Saab engineer Erik Wilkenson maximized its attack capabilities. Reportedly, some B 18B received a PS-18A radar. This version received ejection seats, and had the crew modified, reducing it to two (pilot and navigator/radio operator). 120 units delivered.
  • T 18B – A projected torpedo-bomber to serve as an anti-ship asset, it ended in being a ground-attack plane thus receiving an armament of a 13mm machine gun, 2 x 20mm guns and a 57mm Bofors cannon at the undernose gondola, receiving later on air-to-surface rockets. This version also received ejection seats. 62 units delivered.

Operators

  • Sweden
    The Flygvapnet was the sole operator of the B 18, which entered in service in 1944 with 62 units of the B 18A model, followed shortly by 120 units of the B 18B that were initially purposed as dive bombers, developed later on into the T 18B with 62 units, which served as a ground-attack plane. The T 18B, in turn, was initially purposed to be a torpedo-bomber, but given problems with the new payload, received instead rockets hence serving as attacker. Some airframes were modified to be the S 18A reconnaissance plane, performing reconnaissance missions off the Soviet Baltic coast in the aftermath of WWII. It remained in service until 1958, year in which the Saab 32 Lansen replaced the B 18. It was used for testing the Rb 302 anti-ship missiles. The B 18B operated in 4 squadrons from 1944 to 1958: F1 Västerås, F7 Såtenäs, F14 Halmstad, and F17 Kallinge. The T 18B torpedo-bomber/attack aircraft operated also in the F17 Kallinge from 1948 to 1958. The S 18A operated in three squadrons in the same perios of time: F3 Malmen, F11 Nyköping and F 21 Luleå. A single B 18B recovered from a lake remains as a museum exhibition.

Specifications (B-18B)

Length 13.23m / 43ft 5in
Wingspan 17m / 56ft 9in
Height 4.35m / 14ft / 3in
Wing Area 43.75m2 / 470.92 ft2
Engine 2 X Daimler Benz DB 605 of 1475hp (some were licensed-built versions made by Svenska flygmotor AB).
Maximum Take-Off Weight 8800kg / 19,401 lb
Empty Weight 6100 kg (13,448 lb)
Loaded Weight 8140 kg (17,948 lb) (B 18A)
Maximum Speed 570Km/h / 357 mph
Range 2600 km /1,616 miles
Maximum Service Ceiling 9800m / 32,150ft
Crew 3 (2 in the T-18B)
Armament
  • A 13mm machine gun; 20mm cannon
  • A 13mm machine gun; 2x 20mm cannon; a 57mm gun (T 18B)
  • Up to 1400kg of bombs and rockets (the T18 B was intended to carry a torpedo or a mine, but it ended in having a payload of rockets)

Gallery

SAAB B18B

Sources

Arboga Robotmuseum. (2017). Rb 302. Arboga Robotmuseum.Aviastar.org (n.d.). Saab 18. 1942. Aviastar.org.Hertze, S. (2017). B18, B18A, B18B, T18B, S18A, Saab 18. Arboga Elektronikhistorika Förening AEF.Frederiksson, U. (2005). Saab B 18, the Swedish Air Force’s last propeller combat aircraft. X-plane.org.Henriksson, L. (2010). B18–Saab 18 (1944-1959). Avrosys.nu.Pilotfriend. (n.d.). Saab 18.The Spyflight Website. (2003). Swedish Cold War Reconnaissance.wwiivehicles.com. (2017). Sweden’s Saab B18, Saab 18 bomber. wwiivehicles.com.Saab 18. (2017, May 17). In Wikipedia, The Free Encyclopedia., Images: Saab 18 Forward View by Johnny Comstedt / CC BY-NC-ND 2.0Side Profile Views by Ed Jackson – Artbyedo.com

 

Saab 105

sweden flag Sweden (1967)
Trainer – 192 Built

The Saab 105 is a high-wing, twin side-by-side seat configuration, two engine-powered training and multi-mission jet, with swept-wings. This airplane (later denominated as Sk 60 by the Swedish Flygvapnet) was the product of a private venture by the company, which and after witnessing the success of the S 35 Draken, decided to implement a program with its own funds to develop a new training plane, with military purposes and eventually, civil purposes. The Saab 105 is, in fact, a multi-mission aircraft, in lieu with the operational framework Saab and Sweden normally contemplates for its aircraft. For instance, it can perform missions of training, liaison, ground attack, reconnaissance and limited interception. In regards to civilian use, the small jet was intended to be a four or five-seat business jet, but this plan met no success, making the Saab 105 a military machine and the company to aim at the military market (until the arrival of the Saab 340 and the Saab 2000, the company would not venture into the civil market, although Saab ventured into this market in the Saab 90 Scandia in the 40’s and 50’s). It replaced the de Havilland Vampires that served in the Flygvapnet as training jets.

Saab sk60A - 60140

Noteworthy to point out that this aircraft was a milestone for European aerospace industry, for it was the only small European design in being powered by turbofan engines, increasing the prospects of customers – yet the foreign sales were rather modest, with Austria being the only country in exporting the jet. Nevertheless, it managed to have the attention of the Flygvapnet, placing an order for at least 100 units of the jet, and even sponsoring further development of the jet on an initial training version.

Development

The development programme started in 1961, with the prototype having its first flight in 1963, where the airplane revealed to have very good handling qualities and good manoeuvrability, capable of performing acrobatic manoeuvres. The original powerplant, the Turbomeca Aubisque was tested at the engine’s factory in France with one prototype delivered there solely for that purpose, being later on produced by Volvo under license as the RM9. The powerplant would be updated as time went by, with the Swedish-operated Sk 60 receiving a Williams International FJ44 engine (manufactured by Volvo as the RM15 and fitted with Auxiliary Power Reserves), mainly due to the Aubisque Engines reaching the end of their operational life, and tight defence budgets.

sk60a-trainer-display
In 1966, the Saab 105 entered in service with the Flygvapnet following the Swedish government authorization to incorporate 130 aircraft, with three main variants having specific missions each: the Sk 60A for training and liaison with a four-seat configuration; the Sk 60B for light attack mission with the cockpit having a twin side-by-side seat configuration; and the Sk 60C with ground attack and reconnaissance missions, equipped with cameras at the nose. There was an improved version to be exported to Austria (the Saab 105Ö/ÖE), with better powerplant – a General Electric J85 – and improved avionics, as well as reinforced wings and optimized for high-altitude operations.
The Saab 105 is a four-seat or twin side-by-side seat multi-mission aircraft, having two engines, high-wing, a tail on a T shape and the tail being very wide. The wings are swept-wings, with the cockpit placed very bow of the aircraft and right before the wings, with the engine air intakes placed beneath them and at the forward edge. The canopy is if of bubble type, although it has no free rear vision, as the canopy does not stand above the fuselage. The engine has been updated from time to time, as well as the avionics, with the Austrian version being the version receiving the most important updates. In addition, the Saab 105 is capable of carrying a varied array of armament, such as 135, 127 or 75 mm rockets, Saab Rb05 ASM missiles, bombs and cluster bombs, and 30 mm or 12,7mm (training) guns at gun pods for ground attack missions. Cannons and AIM-9 Sidewinder/ Rb24 missiles can be used for the limited air defence and interception role, and cameras and radiation detecting equipment for atmospheric sampling in reconnaissance missions.

Service

As the Saab 105 entered in service with the Flygvapnet and the Österreichische Luftstreitkräfte in 1966 and 1970, respectively, with 150 units in Sweden and 40 units in Austria, making a total of 190 units (including the prototypes), where they are still in service with both air forces. Thanks to its manoeuvrability, the Saab 105/Sk 60 was used in acrobatic teams at both nations: in Sweden, it is used by the display team Team 60 of the Flygvapnet, whereas in Austria it was used by two Österreichische Luftstreitkräfte teams, Karo As and the Silver Birds. A replacement for the Saab 105/Sk 60 is now being considered, as it has been in service for 40 years, while one of the prototypes is now a museum display since 1992. Nevertheless, an agreement between Saab and the Swedish Armed forces was reached in 2015 in order to support and keep the Sk 60 airworthy until 2020.

Design

The design of the Saab 105/Sk 60 is conventional, although it has some remarkable characteristics that makes this jet to be very different from other airplanes of similar type. The airplane is mate entirely of metal. For instance, the nose is relatively small from longitudinal perspective, yet being wide enough to accommodate the frontal wheel of the landing undercarriage. On the reconnaissance version, its size is increased in order to accommodate the camera equipment and other instruments. The canopy and cockpit are also unique – similar to the Bae 167 Strikemaster and the Hunting (Percival) P.84 Jet Provost in shape – with a ‘bubble’ configuration where two or four crew can accommodate, although it is normal to have a crew of two in training missions. The seat configuration was a twin or side-by-side seating, and in some versions, 4 seats were accommodated in the cockpit.

Noteworthy to remark, the canopy takes more than the half of the height at the bow. Right after the cockpit and canopy the radio antenna is installed above the fuselage, in the same area where the engine air intakes and the wing both start. The wing is a high swept-wing, although is not perfectly strait, as it has a depression angle from the base to the wingtip. Furthermore, the leading edge is swept, while the area of the ailerons and flaps is slightly swept. The wing accommodates six hardpoints (three on each wing) that allows the airplane to carry a varied array of weaponry and depending of the mission it was tasked with.
The engines – the Saab 105 was normally powered by two engines: a couple of Turbomeca Aubisque Turbofan, a couple of Williams FJ44, or a couple of General Electric J85 engines – were placed at the sides of the fuselage, and occupying the whole central section of the jet. The exhausts were placed right before the tail group began, hence the T shape of the tail, with the horizontal stabilizer and elevators placed on top of the vertical stabilizer. The vertical stabilizer in turn, is having a considerable area, giving the tail its characteristic ‘big’ shape, with the rudder having a similar ample area, equal to the Canadair CL-41G-5 Tebuan. Each side of the tail is having a trapezoid shape.

saab-sk60a-in-flight-2

The landing gear is of tricycle configuration, with the frontal wheel located at the nose, and the rear wheels placed at the central area of the fuselage, right beneath the wing and the engines, being retractable.

In regards to the armament, it was normally varied, depending of what were the mission to accomplish. The initial configuration of training and liaison would be unarmed (except for the 12,7mm training guns), yet for its secondary ground attack roles it would be armed with 30 mm or 12,7mm (training guns) guns installed at pods, fitted in the wings, unguided rockets – of 135, 127 or 75 mm –, bombs – either free fall or cluster bombs – and two Saab Rb05 air-to-ground missiles. As it is capable of limited air defence and interception, it can carry the 30mm or 7,62mm guns at the pods and AIM-9 sidewinder/RB 24 air-to-air missiles. Cameras and radiation detecting equipment for atmospheric air samples were the normal equipment for reconnaissance missions. Noteworthy to remark that additional fuel tanks were never intended for use, therefore the wings never carried such equipment. A publicly known Sk60 received important updates in avionics and navigation systems in 2013, constituting itself a new version (Sk 60AU).

A Private Venture

The Saab 105/Sk 60 as the idea of developing a small high-speed business jet featuring a delta wing and cannards with 5 seats, but also due to the success of the Draken and the need for developing a trainer that could train the Flygvapnet pilots for the J 35, moreover when the de Havilland Vampires were not suitable for the task. This realization, along with the fact that the proposed business jet found no fertile ground for success, made of the new Saab 105 to be more a military plane, although some of the 150 built jets were used as liaison and VIP transports. At the same time, the Flygvapnet was requiring new training aircraft, selecting the Saab 105 above other – good – options, such as the Fouga Magister or the Macchi MB.326, to name a few. As a result, the Saab entered in service with the Air Force sponsoring further its development. Some year after in entered in service, Saab engaged in a campaign to export the Sk 60 to other nations – mainly those that were neutral during the cold War, curiously – such as Finland, Switzerland and Austria. Only the last one bought 40 Sk 60, which were enhanced versions of the original model and fitted for Austrian service.

A Small but Versatile Jet

The Saab 105 might look a modest, uninteresting aircraft at first sight, but like all Saab models, it is a very capable jet with very good flying characteristic, being its manoeuvrability the most remarkable one. It was also deemed to be easy to fly, It is also a multi-mission airplane, capable of adapting to different missions. For instance, it can perform training and liaison missions in principle, but it is also capable of executing ground attack, reconnaissance and atmospheric air sampling, and even limited air defence and interception (especially the Austrian units). It has been in service with both the Swedish and Austrian air forces for about 46-50 years, being among the airframes serving for a long period of time with any air force. As a result of its manoeuvrability, it was used by acrobatic teams in both Sweden and Austria.

Variants of the Saab 105/Sk 60

  • Saab 105 – The prototypes of the trainer and liaison airplane. Two prototypes built
  • Sk 60A – The first production series, configured as two-seat trainer and liaison jet, with 149 units built.
  • Sk 60B – The second version configured for ground attack missions and made from modified Sk 60A airframes, incorporating armament.
  • Sk 60C – The third version, configured for ground attack and reconnaissance mission, fitted with a camera (a Fairchild KB-18 panoramic fil camera) that elongated the nose, since it was installed there. A prototype and 29 converted airframes from the Sk 60A comprised the quantity of this version.
  • Sk 60D – Saab reportedly configured the Saab 105 as a four-seat liaison transport, with the combat seats replaced by four airliner-type seat lacking use of parachute, or even four seats of the same type that would allow the use of parachutes by the crew. 10 Sk 60A airframes were modified to give way to this version in the mid-70’s, receiving the same ‘splinter camouflage’ painting applied to the Saab S 37 Viggen
  • Sk 60E – Similar to the Sk 60D version, only that it was fitted with airliner-type instruments, including an instrument landing system. It trained Flygvapen reserve pilots in flying commercial aircraft, used later on as Sk 60D transports.
  • Sk 60W – Intended programme in 1993 to upgrade the Sk 60, were a new powerplant (Williams Rolls FJ44 turbofan engines) and digital engine control were to be installed, as well as LCD altitude indicators. Implemented in 1995, the Sk 60 powered by these engines were denominated informally as Sk 60W. 115 Sk 60A, Sk 60B and Sk 60C were upgraded, while the Sk 60D and Sk 60E were grounded and used for part cannibalization.
  • Sk 60AU – A new version of the trainer, being a modification of an existing airplane, it incorporated new avionics and instruments. Among the upgrades incorporated, there is a GPS, new radio, new audio warning systems, new navigation systems and information on a similar manner as in the JAS 39. Introduced in 2013 with a single unit modified publicly known at F 17 Ronneby.
  • Saab 105XT – An improved Sk 60B powered with a General Electric J85 Turbojet engines made from the second Saab 105 prototype, purposed to be an export demonstrator. The engines, noteworthy to point out, yielded speed of up to 970 km/h, making it a subsonic aircraft.
  • Saab 105D – A proposed refined business jet version, but it was cancelled as there were no takes and the idea was out of time.
  • Saab 105G – A revised version of the Saab 105XT that featured new avionics, such as a precision navigation and attack system, enhanced J85 engines and modified wings, with only one units from a modified Saab 105XT
  • Saab 105H – Proposed training version for the Swiss Air Force. As this air force rejected the project, none were built.
  • Saab 105Ö (105ÖE) – An export version made for Austria and based on the Saab 105XT, entering in service with the Österreichische Luftstreitkräfte in 1970 and 1972, replacing the de Havilland Vampires and Saab J 29 Tunnan this air force was operating with back then. Powered by the General Electric J85 engines
  • Saab 105S – A proposed trainer demonstrator for the Finish Air Force, as it was requiring a trainer in the mid-70’s. Finland decided instead to purchase Bae Hawk trainers.

Operators

  • Sweden
    The Flygvapnet operated the Saab 105 under the denomination of Sk (Skola) 60(A). 150 units served with the Swedish Air Force in 1966 and for unarmed training missions. They began to operate at F 5 Ljungbyhed and the F 16 Uppsala flying schools. At the earlier 70’s the Sk 60A were modified with the installation of hardpoints at each wing, allowing them to operate also as light attackers. 46 units were modified and denominated Sk 60B. At the same time, 30 Sk 60A were modified into the Sk 60C, allowing cannons pods and rockets, as well as the installation of a panoramic reconnaissance camera, serving in the abovementioned wings as well as in the F 21 Luleå, where a light attack squadron was stationed. In 1988-1991 and 1993 the Sk 60s suffered upgrades, mainly at the wing – which were reinforced – and the pilots’ ejection seats, as well as receiving new powerplants. The Sk 60D/E were kept out of any modernization programmes, used instead for cannibalization (or to use the aircraft as sources for spare parts). A single unit so far has been modified with new instruments and GPS devices in 2013 at F 17 wing Ronneby, constituting the Sk 60AU. Similarly, the builder and the air force reached an agreement in 2015 to keep the trainer airworthy and with any maintenance support for this purpose, until 2020.
  • Austria
    Operated 40 Saab 105Ö/ÖE were purchased, with 28 currently remaining. The Österreichische Luftstreitkräfte operates this aircraft mainly for training purposes, but also for other mission such as ground attack, reconnaissance (including radioactivity measurement), VIP transport and limited air defence and interception missions. The Austrian Saab 105 were noticeably operated when US president George Bush visited Austria, performing air patrols under the policy of air guard when a personality or important summits are taking place. It is still deemed a good tool for fighter training by the Austrian Air Force.

Saab 105 Specifications

Wingspan  9,5 m / 31 ft 2 in
Length  10,5 m / 34 ft 5,83 in
Height  2,7 m / 8 ft 9 in
Wing Area  16,3 m² / 175,5 ft²
Engine  2 x Turbomeca Aubisque (Volvo Flygmotor RM9), or 2 x General Electric J85-17B Turbojet, or 2 x Williams FJ44 (Volvo Flygmotor RM15)
Maximum Take-Off Weight
Empty Weight  2510 kg / 5,533 lb
Loaded Weight  2835 kg / 6,240 lb
Maximum Load  800 kg / 1,763 lb
Climb Rate  75m/s (Saab 105Ö/ÖE)
Maximum Speed  770 km/h / 360 mph at 6095 m (19,996 ft)
Range  1400 Km / 790 miles
Maximum Service Ceiling  13500 m /44,291 ft
Crew  2 (instructor pilot and student pilot) or 4 in case of liason/VIP transport mission (Sk 60D/E)
Armament
  • 6 harpoints allowing up to 700kg (1,543 lb) of payload: 2 x Saab Rb05 ASM missiles
  • 2 x AIM-9 Sidewinder/Rb24 AAM missiles
  • Pods for 30 mm or 12,7 mm cannons
  • 12 X 135mm, 127mm or 75mm rockets
  • 250kg (550lb) bombs, cluster bombs and rocket launcher pads.
  • The reconnaissance version was equipped with a Fairchild KB-18 panoramic camera at the nose, as well as radioactive air measurement instruments.

 

Gallery

Saab sk60A - F 5 Ljungbyhed - 60113 Side Profile View
Saab sk60A – F 5 Ljungbyhed – 60113
Saab sk60A - F 5 Ljungbyhed - 60140 Side Profile View
Saab sk60A – F 5 Ljungbyhed – 60140
Saab sk60A - 60088
Saab sk60A – 60088

sk60a-trainer-display

saab-sk60a-in-flight-2

Saab sk60A - 60140

 



Sources

Airheadsfly.com. (2013). Upgraded SK60 Operational. Airheadsfly.com.Charleville, J. (1996)., Nya SK 60: Inte W men A, B, C., FlygvapenNytt (4), 25.Das, W., & Otten, K. (n.d.). Saab 105 in Austrian Air Force. Dutch Aviation Support.Flygrevin. (2012). SAAB Sk-60 – flygande skolbänk. Flygrevyn (2), 2-6.Fredriksson, U. (2001). Saab 105 in Swedish service. X-plane.org.Försvarsmakten. (2013). F17 har fått en ny versionen av SK 60. Försvarsmakten.Globalsecurity.org. (2012). Sk60 / Saab 105 trainer/light attack aircraft. Globalsecurity.org.Goebel, G. (2016). SAAB Trainers: Safir, SAAB 105, & Supporter. Airvectors.net.Hultgren, O., & Moberj, T. (1998). Abstract, in Saab 105 “SK60” Re-Engine Programme. Defence Materiel Administration Testing Directorate. Linköping, Sweden. , Peterson, G. (1997). Saab 60 år. Saab 1937-1997: Dramatik och dynamik, FlygvapenNytt, (3) 6-17.Saab. (n.d.). 1960’s. Saab.Saab. (2015). SAAB Signs Sk60 Support Agreement with FMW. Saab., Sharpe, M (2001). Jets de Ataque y Defensa [Attack and Interceptor Jets, Macarena Rojo, trans.]. Madrid, Spain: Editorial LIBSA (Original work published in 2001)., Saab 105. (2016, October 8). In Wikipedia, The Free Encyclopedia. Images: Saab sk60A in Flight by Jim Calow / CC BY-ND 2.0, Saab sk60A in Flight 2 by John5199 / CC BY 2.0, Sk60A Trainer Display by Alan Wilson / CC BY-SA 2.0Side Profile Views by Ed Jackson – Artbyedo.com

Saab 21R - Flightline

Saab 21 / 21R

sweden flag Sweden (1945)
Fighter / Attack Plane – 298 Built

The Saab J 21 is a peculiar airplane, not only because of its advanced features. This fighter in particular is the only airplane that was initially powered with a piston-propelled engine, then later modified to incorporate a jet engine using the same airframe and implementing very few modifications. This airplane is also the product of Swedish defence concerns and resourcefulness, as Sweden wanted to keep its neutrality and territorial integrity during WWII, electing to develop a domestic fighter program as access to foreign advanced technology was restricted.

Saab J 21A-3 in a Hangar
Saab J 21A-3

A single-seat, single-engine airplane that later became one of the first-generation jet fighters. Its design is a twin-boom tail pusher configuration. It had two longitudinal booms, attached to the main wing but extending backwards from the middle section of each wing, with the main body placed in the middle. Similar to the Lockheed P-38. This design also implements a rear mounted piston engine, otherwise known as a pusher configuration, which made engine modifications easy.

The piston-propelled version, the J 21 – had the engine, a licensed Daimler-Benz DB 605B, simply fitted at the rear of the main body, behind the cockpit and between the longitudinal booms. The jet version – J 21R – was fitted with air in-takes at both sides of the fuselage, having the engine (a De Havilland Goblin 2 and later a Swedish-licensed version, a Flygmotor RM1) located on the same area as the piston-propelled version and elongating the main body. The fuselage section harbouring the engine was also widened. Another modification was that the elevator was placed at the upper area of the double tail plane. The wing in both configurations was a low-wing, being straight until it met the longitudinal booms, changing into a slightly swept wing from the longitudinal boom to the wing tip. It also received wingtip fuel tanks.

The J 21 could develop speeds up to 645 km/h (400,78 mph), while the jet propelled version could develop speeds up to 800 km/h (497 mph), being a fast aircraft in both configurations. Its firepower (J 21) was equally powerful, as it was armed with a 20 mm cannon, either a Bofors or a Hispano-Suiza HS.404, and 2X 13,2mm Bofors machineguns at the nose, with 2X 13,2mm Bofors machineguns in the wings. The J 21R received an even much more considerable firepower, as it featured a 20mm Bofors cannon, 4X 13.2mm M/39A heavy machine guns, a centreline pod with 8X 13.2mm M/39 machineguns, and wing racks for 10X 100mm, 5X 180mm, or 10X 80mm anti-armour rockets.

Saab J 21 Prototype
Prototype in Service

The J 21 was initially developed with the aim of providing Sweden with good air assets to defend its air space and neutrality, and also with the aim of replacing many of the existing airplanes development. The development began in 1939, under the lead of Frid Wänström, having as basis a Bristol Taurus as an engine, yet it fell into a momentary freeze until 1941, when it was resumed. This freeze was due to Saab’s concentration in the Saab B 17 and B 18 bombers. As the configuration resulted problematic for the pilot’s safety when bailing out, many proposed solutions came, such as blowing the propeller, blowing the entire engine or using a “bomb crutch” to throw the pilot away from the airframe. The solution came with the development and implementation of a Bofors ejection seat, which was tested first on ground and in-flight on a SAAB B 17. The nose landing gear wheel was tested on a steel platform attaching the three undercarriage components, with the structure being towed by a truck during the test programme. In 1943 the first flight of the prototype took place, with units entering in service with the Flygvapnet in 1945. Three prototypes were built during the development process. In 1947 the J 21 evolved into de J 21R when it received the De Havilland Goblin jet engine, but as the J 29 Tunnan was introduced, it replaced the J 21 as the main fighter, performing the J 21 instead ground attack missions, thus designated A 21R.

The J 21 was in service with the Flygvapnet from 1945 until 1954, with 298 fighters built from 1945 to 1949. The J 21R was in service with the Flygvapnet from 1950 until 1956, with 60 units built from 1950 to 1952. Three J 21 are preserved as static displays in museums.

Design

Saab 21 R
The jet powered Saab 21 R in flight

The basic design of the J 21/J 21R was a twin-boom tail pusher propeller, making it one of the most radical operational designs of those times. This scheme proved to be beneficial for two important aspects. First, it benefited both pilot view forward and allowed the armament to be concentrated on the nose, meaning that such combination provided a good firing scope and sight, let alone a good firepower and making maintenance services rather easy. Second, it made possible for the aircraft to be updated thus being able to install a jet engine using the same airframe of the piston-propeller engine version, which was basically the basic airframe.

The only drawback of this layout – mainly with the J 21 piston-propelled engine version – was the risk for the pilot to hit the blades when bailing out, as the engine was placed right behind the cockpit. The solution came with one of the first ejection seats in the world, developed by Saab in 1943, being tested on the ground and on-flight and being a SAAB B 17 the testing platform. Another drawback was that, similar as the earlier versions of the Mustang P 51, the rearward view was rather poor, which could be problematic in a dog-fight. The J 21 featured a characteristic wing, as it was roughly strait from the main fuselage to the tail twin-booms, then being slightly swept back from the tail booms to the wingtips.

The wing was purposed with acquiring laminar flow as far as possible. In regards to the aerodynamics, it was required the airframe to reduce minimum drag and engine cooling drag, so the oil and liquid coolers, along with the duct system for the engine, inside the airfoil contour between the fuselage and the tail booms. Considering the tail boom design, the horizontal elevator was placed between the tail sections, connecting them. The landing gear, meanwhile, was of tricycle configuration and long, which made the J 21 to be a tall aircraft so to keep the propeller away from the ground. The rear gear retracted into the tail booms behind the rear wing spar, but this forced the fuel tank to be placed in the wing centre section. The frontal wheel was located at the nose.

The engine was a Daimler-Benz DB 605B inverted V12 of 1475 hp, which gave the airplane speeds of maximum 645 km/h (400,78 mph), but as the engines were received in poor conditions, improvements and overhauling were required. As a result of the power provided by this engine and the aerodynamic characteristics, the J 21 was deemed good, as it had excellent handling, benign stall characteristics and tight turning circle. The armament also gave this fighter good firing power, with the Swedish pilots being able to compare it with the Mustang P 51D (Sweden received a good number of them) and considering they were a good match for it. But the main drawbacks were that at medium and high altitudes performance tended to decrease, the rearward view was poor, and the controls were heavy to operate, increasing tiring during combat.

The armament of the J 21 consisted of a 20 mm cannon, either a Bofors or a Hispano-Suiza HS.404, and 2X 13,2mm Bofors machineguns at the nose, with 2X 13,2mm Bofors machineguns in the wings. The J 21A-3 was able of carrying unguided rockets (2X 180mm or 8X 80/145mm) and bombs (600kg, 500kg, 250kg or 4X 50Kg).

Saab 21 Cockpit

After World War II, the jet engine technology was becoming the mainstream propulsion system, and the Flygvapnet wanted to catch up and incorporate such technology into its assets. As the development of a new jet propelled fighter would take some time, the J 21 was chosen to be the platform for using an airframe in use with the new technologies back then. As a result, the J 21R was developed and introduced, with the first prototype taking flight in 1947 and then entering service in 1950. This ‘new’ fighter required some structural changes so to cope with the new power plant, like up to 50% of its airframe. First, the main body was slightly prolonged ant widened, so to allow the De Havilland Goblin 2/Flygmotor RM1 engine (that allowed speeds of 800 km/h) and the air intakes, located at each side of the fuselage. In addition, the stabilizer was moved upwards top to the fin, so to allow the engine flow, requiring the tails to be redesigned. The wing leading edge was mover forward and made sharper. Airbrakes were introduced, one upward and other downward flaps placed on the outer wing’s trailing edge. Given the increased speed, the ejection seats were properly modified so to enable ejections at subsonic speeds. And as the propeller was removed, the landing gear was shortened in turn, reducing the height of the airplane. Fuel tanks were fitted in the middle wing and the wingtips, which increased the fuel volume.

The J 21R received an enhanced firing power, as the standard 20mm cannon/4X 13,2mm M/39A heavy machineguns set was added with a centreline external pod carrying 8 additional 13,2mm M/39 heavy machineguns. In addition, the J 21R was fitted with wing racks allowing the airplane to carry 10X 100mm or 5X 180 Bofors rockets, or 10X 80mm anti-armour rockets.

Materializing ‘Armed Neutrality’

The J 21 is, like the J 29 Tunnan, the product of Sweden’s concerns about its own security during WWII, especially in the light of Germany’s invasions of Norway and Denmark in 1940, which were neutral nations by the time. As Sweden considered that its existing air assets wouldn’t be able to successfully contribute to the defence, given their obsolete condition, it considered that new aircraft were necessary. As with the J 29, Sweden faced some problems when trying to acquire some technology due to the restrictions imposed by the conflict, although by sheer luck it was able to receive the Daimler-Benz DB 605B engine, as Germany was trying to hamper the delivery. These circumstances decided the Swedish government to undertake a local rearmament programme and implement a policy of ‘armed neutrality’ to secure the nation’s neutrality. The focus was placed on the development and fabrication of advanced aircraft. As the same concerns prevailed after World War II and into the very earlier days of the Cold War, it was deemed that the resulting technologies from the War needed to be exploited and incorporated, having in mind Sweden to catch up with the newly developed technologies, especially in regards of propulsion. The Saab J 21 became the platform for the Flygvapnet to make the transition from piston-propeller engine to jet engine, while at the same time providing the country with a locally built jet engine fighter, while newer and more advanced aircraft were put into service.

A feat of Swedish Nytänkande

The fact that the J 21 was used as a basis for an almost new jet powered engine fighter is a product of Sweden’s innovative thinking and also of its capacities – out of need, in part – of working with existing resources at the point of maximizing them. While the J 29 Tunnan has the honour of being the first jet fighter exclusively built for that purpose, it is the J 21 the very first jet engine fighter the Flygvapnet operated with, being amongst the very few designs, if not the only one, in being successfully modified as it received two different types of power plants. And while the J 29 Tunnan displaced the J 21 as a fighter, it was able to operate as a good ground attack aircraft until 1956, making this airplane born in the World War II, an early Cold Warrior and the basis for Sweden’s jet fighter industry and operationalization. It simply meant a huge step for the Swedish Air Industry, let alone its Air Force.

Variants of the J 21

  • J 21A-1 – Fighter version and the very first production series of the J 21. It featured the armament configuration of the 20mm Hispano-Suiza HS.404 cannon and the 13,2mm Bofors/Colt heavy machine guns. In service until 1949. 54 delivered.
  • J 21A-2 – Fighter version and the second and third production series, featuring enhanced avionics and incorporating a Bofors 20mm gun, with the other armament being the same. It was also equipped with further direction horizon instruments. In service until 1953-1954. 124 delivered.
  • J/A 21A-3 – Fighter/fighter-bomber version based from modified J 21A-2 airframes. It was equipped with a SAAB BT9 bomb aiming sight and two RATO (Rocket-Assisted Take-off) devices, armed with unguided rockets (2X 180mm or 8X 80/145mm) and bombs (600kg, 500kg, 250kg or 4X 50Kg). 119 delivered.
  • J 21B – A planned version to be armed with 3X 20mm guns at the nose, a radar in the starboard room, improved aerodynamics and better engines (A Daimler-Benz DB 605E/Rolls-Royce Griffon). It was also intended to feature a pressurized cockpit and a bubble canopy. Cancelled

Variants of the J 21R

  • J 21RA / A 21RA – First production series powered by a De Havilland Goblin engine. Later reconfigured into ground attack airplanes (A 21RA). Fitted with wingtip fuel tanks to increase the operational range and endurance. Operated until 1953. 30 delivered.
  • J 21RB / A 21RB – Second production series powered by a Swedish-license made De Havilland Goblin (RM1). It was also reconfigured later into a ground attack airplane (A 21RB), with the nose heavy machineguns changed to a 12.7mm caliber. Fitted with wingtip fuel tanks to increase the operational range and endurance. Operated until 1956. 30 delivered.

Operators

  • Sweden -The Flygvapnet operated the J21 a time roughly after the end of World War II. It operated with 54 fighters of the J 21A-1 version, 124 The J 21 fighters of the J 21A-2 version, and 119 fighter/bombers of the J 21A-3 version. The J 21 was in service between 1945 and 1954, with X units: F9 Goteborg, F15 Soderhamn, F12 Kalmar, F6 Karlsborg and F7 Såtenäs. In addition, the Flygvapnet operated with 30 fighters of the J 21RA version, and 30 fighters of the J 21RB version. Both were later on modified into ground attack airplanes, being denominated as a result A 21RA and A 21RB. The J 21R was in service from 1950 to 1956, with three units: The F10 Ängelholm, the F7 Såtenäs, and the F17 Kallinge. Three J 21 remain today as museum exhibitions in Sweden.

 

 

21 Specifications

Wingspan  11,6 m / 38 ft 0 in
Length  10,44 m / 34 ft 3,02 in
Height  3,97 m / 13 ft 0 in
Wing Area  22.2 m² / 238,87 ft²
Engine  1 Daimler-Benz (SFA) DB 605B inverted V12 of 1475 hp
Maximum Take-Off Weight  4431 Kg / 9,768.6 lb
Empty Weight  3250 kg / 7,165 lb
Loaded Weight  4150 kg / 9,149 lb
Maximum Speed  645 km/h / 400,78 mph
Range  750 Km / 466 miles
Maximum Service Ceiling  11000 m /36,090 ft
Climb Rate  15 m/s (2,950 ft/min)
Crew 1 (pilot)
Armament
  • 1 X 20 mm Hispano-Suiza HS.404 or a Bofors cannon located at the nose.
  • 2 X 13,2 mm Bofors (Colt) heavy machine guns located at the nose.
  • 2 X 13,2 mm Bofors (Colt) heavy machine guns located at the wings.
  • The J 21A-3 fighter/bomber version could carry also 2 X 180mm, or 8X 80/145mm rockets; and 600kg, 500kg, 250kg or 4X 50Kg bombs

 

21R Specifications

Wingspan  11,37 m / 37 ft 4 in
Length  10,45 m / 34 ft 3 in
Height  2,90 m / 9 ft 8 in
Wing Area  22.3 m² / 260,0 ft²
Engine  1 De Havilland Goblin 2 Turbojet (Svenska Flygmotor RM2B Turbojet)
Maximum Take-Off Weight  5000 Kg / 1,0230 lb
Empty Weight  3200 kg / 7,055 lb
Loaded Weight  N/A
Maximum Speed  800 km/h / 497 mph
Range  720 Km / 450 miles
Maximum Service Ceiling  12000 m /39,400 ft
Climb Rate  17.1 m/s (3,366.1 ft/min)
Crew  1 (pilot)
Armament
  • 1 X 20 mm Bofors cannon located at the nose.
  • 4 X 13,2 mm M/39 heavy machine guns located at the nose, later changed to 12.7mm caliber.
  • 8 X 13,2 mm M/39 heavy machine guns on a centreline pod.
  • Wing racks allowing 10X 100mm, 5X 180mm, or 10X 80mm anti-armour rockets.

Gallery

Saab J 21A-1 - Prototype
Saab J 21A-1 – Prototype
Saab A 21A-3 - 21364
Saab A 21A-3 – 21364
J 21R - Prototype
Saab J 21R – Prototype
Saab A 21R Trainer - 21455 Side Profile View
Saab A 21R Trainer – 21455
Saab J 21R - 21463 w/ Gun Pod Side Profile View
Saab J 21R – 21463 w/ Gun Pod

Saab A 21A-3 Converted J21R Converted J21R 2

Saab 21 R
The jet powered Saab 21 R in flight
Saab J 21 in Service
Saab J 21 in Service
Saab J 21 Prototype
Prototype in Service
Saab J 21A-3 in a Hangar
Saab J 21A-3
Saab 21 Cockpit
Saab 21 Cockpit
Saab 21R - Flightline
Saab 21R – Flightline

Sources

Chant, C. (2001). Aviones de la Segunda Guerra Mundial [Aircraft of World War II, Fabian Remo Tamayo & Fernando Tamayo, trans.]. Madrid, Spain: Editorial LIBSASharpe, M. (2001). Jets de Ataque y Defensa [Attack and Interceptor Jets, Macarena Rojo, trans.]. Madrid, Spain: Editorial LIBSAGoebel, G. (2014). The SAAB J 21 & J 21R. Air Vectors.Frederiksson, U. (2000). Saab J 21/A 21/A 21R. x-plane.org,  Aviastar.org (n.d.). Aircraft Profile #138. Saab J.21A & R.Aviastar.org (n.d.). Saab 21R. 1947.NGO valka.cz. (2015). Saab J 21R.Saab. (n.d.). 1940’s.SAAB 21. (2016, June 23). In Wikipedia, The Free Encyclopedia.Saab 21R. (2016, June 8). In Wikipedia, The Free Encyclopedia., Images: Converted J 21R, Converted J 21R 2Saab A 21A-3 – Alan Wilson / CC BY-SA 2.0, Side Profile Views by Ed Jackson – Artbyedo.com

Tunnan Front View

Saab 29 Tunnan

sweden flag Sweden (1950)
Fighter Plane – 662 Built

The Saab 29 Tunnan was a single-seat, single-engine transonic aircraft and first-generation jet fighter. It was a small aircraft with a single central air intake placed at the nose, a bubble cockpit and  thin sweptback wings. It was the very first Western European design to have a swept wing layout of 25 degrees rearward, incorporating many of the latest technologies of the time. Saab obtained access to WWII German studies involving swept wings and their positive effects in regards to speed in Switzerland, and as a result, the J 29 Tunnan came to be similar to the German Luftwaffe’s Messerschmitt Me P1101 project.

Nazi P.1101 vs Saab Tunnan

The Tunnan acheived a top speed of 1035 km/h which made it one of the fastest aircraft in the world in 1950. The nickname: ‘Flying Barrel’ was coined due to the shape of the fuselage, which came to resemble the shape of a barrel due to the large cross section of the engine and the size of the engine itself with a tapered nose and aft section. The Tunnan’s ungainly and small appearance could be deceiving  however it was fast enough to set several world speed records and also had a very good agility. However, the aircraft proved challenging for inexperienced pilots. The 29 was comparable to its contemporaries: the US-made F-86 Sabre and the Soviet-made Mig-15.

The development aimed initially at producing a fighter-interceptor, but reconnaissance and ground attack versions were also developed and produced, however a training version was not produced due to time constraints of the production schedule. Sweden was developing a strong air defence system that enabled it to take advantage of innovations introduced in WWII. As a result, by late 1945 the development of the Tunnan began, with the Swedish Royal University of Technology and the National Aeronautical Research Institute taking part by providing wind tunnel testing that defined the general aerodynamics of the Tunnan. Just like the Saab J32 Lansen, a single Saab Safir was modified, fitting swept wings to its airframe in order to test the design of the wings alone.

Four prototypes were built during the development process, with the first two lacking any sort of weaponry carrying heavy testing equipment instead, and the third prototype carrying four 20mm Hispano Mark V cannons. These prototypes tested different aerodynamic features, such as the location of the airbrakes – either in the fuselage or on the wings, as well as the configuration of the ailerons and flaps. The prototypes also hinted that the Tunnan design would be able to reach and even exceed the maximum Mach they were designed for. Once in service the Tunnan broke many records. It set a world speed record on a 500 km closed circuit as it reached a speed of 977 km/h in 1954. The reconnaissance version set also a record of 900.6 km/h in a closed circuit of 1000 km.

In 1948, the J 29 Tunnan flew for the first time, in service with the Flygvapnet from 1951 until 1976, with 662 fighters built from 1950 to 1956 making the Tunnan the most numerous aircraft produced Saab, as well as the longest lived design in service. It also served with the Austrian Air Force with 30 units in service until 1973. A single J 29F still can be seen flying at airshows around Europe.

Design

The Tunnan is a thin 25 degrees swept back laminar-flow mid-wing fighter, having a single tail and a single engine, featuring the design similar to most of the first generation jet fighters: a single engine with a central straight-through airflow system that maximized thrust. Two tubular pitot sensors were located at the wing tips. For lateral stability during take-off and landing, automatic-locking leading edge slots were fitted in the wings and were also interconnected with the flaps. It was later on enhanced with the installation of an afterburner and of dog-tooth leading edge in the wings – which increased the Mach speed the Tunnan could attain. Trim tabs and dive brakes were also incorporated to the design, being initially placed on the wings and later re-located to the fuselage, directly forward of the main landing doors.

The Tunnan also featured a bubble shaped canopy with the cockpit located right above the engine air intake, and forward the wing’s leading edge. The canopy was opened by sliding backwards, allowing the pilot to access and exit. The design also took advantage of the already existing ejector seat developed in 1943 by Saab, complemented by an explosive jettison system to remove the canopy in case of ejection. The landing gear was of tricycle configuration, with the rear wheels retracting into the fuselage, which contributed in making the wings thin, and a single wheel gear at the nose. The vertical stabilizer had a tapered edge, being straight trailing edge with a blunt tip, with the tail section placed above and behind the engine exhaust nozzle. In turn, the horizontal stabilizer is mounted practically at the base of the tail. The Tunnan proved to be not only a very capable and agile fighter, but also proved very durable in sorties. During a UN mission in the Congo it received intensive ground fire without sustaining any noticeable damage.

The engine, along with its aerodynamic characteristics, made of the Tunnan a fast fighter. The powerplant consisted of a DeHavilland Ghost turbojet engine producing 5000 lbs of thrust. This engine was deemed suitable for the fuselage of the Tunnan, replacing the originally planned DeHavilland Goblin, and had the advantage of making maintenance easy with the engine cowling able to be removed as a single piece.

The armament of the Tunnan consisted of four 20mm Hispano Mark V cannons placed in pairs on both sides under the nose. The pylons were capable of carrying 75mm air-to-air rockets, 145mm anti-armour rockets, 150mm HE (High Explosive) rockets and/or 180mm HE anti-ship rockets. Later versions were capable of using Rb24/AIM-9 Sidewinder air-to-air missiles. Fuel air-drop tanks could be used as napalm bombs.

Swedish Resolve

Tunnan Banking Maneuver
Tunnan Banking Maneuver

The Tunnan is the product of Swedish concerns about its security during World War II, in the face of Germany’s rapid annexations of both Norway and Denmark and acknowledging the country was unable to resist such aggression. But there were also of concerns that Sweden was falling behind after the rapid development of technologies and innovations brought about during the war. Sweden’s isolation in this aspect was exacerbated by the degree of defense secrecy by both the Axis and Allied countries. As a result, an effort was made in order to strengthen defensive capabilities with the focus being placed on the development of modern aircraft to bolster air defence, exploiting the war-time innovations in power – namely the recently introduced jet propulsion technologies as well as other advances in aircraft design. The new technologies were exploited after Sweden obtained access to research after the war. The already existing Saab J 21R was utilized to make the transition between the piston and jet propelling engines and to provide a temporary solution, but it was deemed necessary to develop a much more modern aircraft in order to keep the air defences fit. The Tunnan became the solution, making the Swedish Air Force the 4th largest during the mid-century.

Peacemaker from the North

All the aircraft produced by Saab and in service with the Flygvapnet from 1948 to 1989 saw relatively little combat. The Tunnan constitutes the only exception, as it saw extensive use during conflict in Central Africa. As the crisis in the Congo unfolded in 1961, Sweden contributed five J29B Tunnans that were tasked with protecting UN’s air transport and providing fire support to cover UN ground troops when needed, constituting the F22 unit. In 1962, four additional J29Bs and two J29Cs were sent. The 11 Tunnans provided by Sweden to the UN mission comprised the only air component of the UN at the time. As the crisis evolved and the additional six Tunnan were required, air superiority was achieved along with ground attack missions that involved the utilization of the fighter’s 4 Hispano cannons and rockets. The missions mainly focused attacks on military trains and airfields at Katanga, as other aerial assets from Ethiopia – F 86 Sabres – and India – Canberra light bombers – withdrew. When the UN peacekeeping mission was over in 1963, four of the Tunnans returned to Sweden, while the remaining met an ignominious ending, destroyed at the base, as it was deemed prohibitively expensive to return them.

Variants

  • J 29 – Four prototypes built in 1948-1950, for the development process only.
  • J 29A – Fighter version. Armed with four 20mm Hispano Mark V cannons, and 12 75mm anti-armor rockets. Later series relocated the wing-mounted dive brakes into the fuselage. Remained in service until 1965. 224 delivered.
  • J/A 29B – Fighter/attacker version. It featured an increased 50% fuel capacity and wing hardpoints with provisions to carry bombs, rockets – 8 or 14 80mm or 145mm anti-armour; 8 or 14 150mm HE; 2 or 4 180mm anti-ship – and fuel drop-tanks that could be used as napalm bombs. Served until 1965. 332 delivered.
  • J 29C – Reconnaissance version for day and night operations. It carried between 5-6 cameras in a modified nose, being unarmed cameras replaced the 4 guns. It received the same wing enhancement of the J 29E. It also became the first jet-powered photographic-reconnaissance aircraft introduced by a non-aligned nation, as well as the first Swedish aircraft to be equipped with radar warning receivers. An antenna for backwards-looking radar was placed at the tail cone, being afterwards relocated  This version set a new speed record back in 1955, reaching speeds 900.6 km/h (559.6 mph) in a closed circuit of 1000 kms (621.4 miles). 76 delivered.
  • J 29D – A single unit to test the DeHavilland Ghost RM2 turbojet fitted with an afterburning thrust, later upgraded to J 29F.
  • J 29E – Fighter version, which incorporated an enhanced wing design by fitting leading edge dogtooth, aimed at increasing critical Mach number. It also increased load factor. Same armament configuration as the J 29B. Upgraded to the J 29F version. 29 delivered.
  • J 29F – Fighter version, which were modified J 29B and J 29E airframes. This version featured the enhanced wing design of the J 29E, and the DeHavilland Ghost engine equipped with an afterburner. This version was also optimized to carry two Saab Rb24 (AIM-9 Sidewinder) missiles in 1963, having the same armament payload of the J 29B. It also performed in the role of aggressors, and performed target towing. Most were retired by 1967. 308 converted aircraft.
  • SK 29 – Planned training version. It could have featured a two-seated cockpit, with seats placed side-by-side, no armament and limited fuel capacity. Cancelled.
  • J 29R – All-weather fighter version equipped with an air intercept radar. Cancelled.

Operators

  • Sweden – The Flygvapnet operated the Tunnan from 1951 to 1967, having 665 units operating, all of the J 29A, J/A 28B, J 29C, J 29E and J 29F versions. Some were kept for countermeasures trainers and target towing duties until 1976. 11 J 29Bs and J 29Cs took part in the United Nations Operation in the Congo (ONUC), being the only Tunnan, and actually the only aircraft during the Cold War of the Swedish Air Force to take part in combat operations abroad.
  • Austria – The Österreichische Luftstreitkräfte (Austrian Air Force) operated 15 restored J 29Fs by Saab in 1961, where they formed the first Jagdbomber Staffel. An additional 15 restored J 29Fs were sold to Austria, where the two guns on the port side could be replaced by three cameras, which were moveable during flight forming the second Jagdbomber Staffel in the Austrian Air Force. These remained in service until 1972.

 

J 29F Tunnan Specifications

Wingspan 11 m / 36 ft 1 in
Length 10.23 m / 33 ft 6.7 in
Height 3.75 m / 12 ft 3.6 in
Wing Area 24.15 m² / 260 ft²
Engine 1 DeHavilland Ghost 50 Turbojet (Svenska Flygmotor RM2B Turbojet)
Maximum Take-Off Weight 7,530 kg / 16,600 lb
Empty Weight 4,580 kg / 10,097 lb
Loaded Weight 13,529 kg / 35,273 lb
Maximum Speed 1,035 kmh / 643 mph (1,075 kmh / 668 mph in full afterburner)
Range 1,500 Km / 932 miles
Maximum Service Ceiling 13,700 m / 45,000 ft
Climb Rate 2,400 m/min (7,874 ft/min)
Crew 1 (pilot)
Armament
  • 4 X 20 mm Hispano Mark V located at the nose
  • 2 Saab Rb 24 (AIM-9 sidewinder) missiles
  • 75mm air-to-air rockets
  • 80mm or 145mm anti-armour rockets, 150mm HE rockets, and/or 180mm HE anti-ship rockets.
  • 4 X SKa 10 cameras, 1 X SKa 15 camera for mapping, and 1 X SKa 5.
  • 2 X fuel drop tanks that could be used as napalm bombs.

Gallery

Saab J 29A Tunnan - 29606 Side Profile View
Saab J 29A Tunnan – 29606
Saab J 29A Tunnan - 29670 Side Profile View
Saab J 29A Tunnan – 29670
Saab S 29C Tunnan - Congo Conflict of 1961 Side Profile View
Saab S 29C Tunnan – Congo Conflict of 1961
Tunnan Landing Gear
Tunnan Landing Gear
Tunnan Front View
Tunnan – Front View
Tunnan Afterburner
Tunnan Afterburner
Tunnan Banking Maneuver
Tunnan Banking Maneuver
Tunnan Taxiing
Saab J29 Tunnan – 29670
S 29C Tunnan in UN service in 1961
S 29C Tunnan in UN service in 1961
Nazi P.1101 vs Saab Tunnan
The P.1101 of Nazi Germany compared with Saab’s Tunnan a few years later



Sources

Ängelholms Flygmuseum (n.d.). Flygplan J29 Tunnan Historia.Aviastar.org (n.d.). Aircraft Profile #36. Saab J.29.DefenceViewpoints. (2015). Five generations of US jet fighters.Dorn, W. (2013). The UN’s First “Air Force”: Peacekeepers in Combat, Congo 1960 – 1964.Goebel, G. (2016). The SAAB 29 Tunnan & SAAB 32 Lansen. Air Vectors.Guttmann, J (1998). Defining the Jet. HistoryNet.Henriksson, L. (2010). J 29 – SAAB “Flygande Tunnan” (1951-1979).Johnson, D. (2010). Messerschmitt Me P.1101. Luft46.com., Liander, P. (2002). För 50 år sedan… J 29 Tunnan gör entré. FlygvapenNytt, (2), 34-35, Saab. (2014). J-29 Tunnan in UN Service.Saab. (2015). J-29 Tunnan Fighter, Attack and Surveillance Aircraft.Saab. (n.d.). 1940’s.Wagner, P. J. (2009). Air Force Tac Recce Aircraft. Pittsburgh, Pennsylvania: RoseDog Books.Werner, B. (2011). J29 Tunnan, Saab.Saab 29 Tunnan. (2016, July 16). In Wikipedia, The Free Encyclopedia. Images: Tunnan-29670-1997 by Rob Schleiffert / CC BY-SA 2.0, Tunnan Underside + Tunnan Gear by Alan Wilson / CC BY-SA 2.0, Tunnan Taxiing by Anemone Nemorosa / CC BY 2.0, Tunnan Afterburner by SteveH1972 / CC BY-ND 2.0

 

Saab J32 Banking Maneuver

Saab 32 Lansen

sweden flag Sweden (1952)
Fighter Plane – 452 Built

A tandem two-seat, single-engine transonic aircraft. Intended initially as an attack aircraft, it was later developed into fighter, reconnaissance, and ECM versions thanks to the aircraft’s size, which allowed the development of the aforementioned variants. The aircraft also had low swept back wings and similar elevators located on the tail. Developed in order to replace the WWII-era light bombers, attack and reconnaissance Saab B 18/S 18, the Saab J 21R/A 21R, and provide a ground-attack complement to the Saab J 29 Tunnan. It was also developed after Flygvapnet requested an aircraft capable of attacking anywhere along Swedish long coastline within one hour after taking off from a central location, and to be capable of operating in any weather conditions, and in both day and night.

Development of the Lansen

Saab J32D Lansen - 32606

Lansen development began by 1946 with the project P1150, where a configuration of two engines was at first considered but latter scrapped given many accidents with foreign aircraft having such display. A Saab 91 Safir, a piston/propeller engine training light aircraft was modified by incorporating the swept back wings intended for the Lansen, in order to test the design. Its first flight took place in 1952, being a very advanced concept in both design and configuration, as it was an aircraft with the best design and quality in comparison to any other European design of the times. In fact, it is among the first designs in incorporating a radar. Another interesting fact is that the Lansen was the first aircraft to be designed upon a mathematical coordinate system, instead of blue prints. It also broke the sound barrier in 1953, as it exceeded Mach 1 while performing a shallow dive. In 1956 it entered in service with the Flygvapnet. 452 aircraft were built between 1954 and 1960, remaining in service until 1997, although three Lansen with experimental, research and test and trial tasks were still operating as of 2012.

Design

Saab Lansen and Hawker Hunter in Formation
Saab Lansen and Hawker Hunter

The Lansen is designed as a swept back low-wing fighter, with a single tail and a single engine, a Volvo Svenska Flygmotor RM6A, enabling a maximum speed of 1123 km/h. The Lansen was among the first aircraft to be built specifically for attack missions. Its airframe was a sleek, streamlined and clean design, in which every line was calculated using a mathematical early computer-based design. It could sustain +12g and -8g. Its low wings had a 35° sweep and a composition of up to a 10° laminar profile, having hydraulically-boosted ailerons. One-section stall fences were installed on the wings, a pitot tube on the right wing and three hardpoints. The landing gear was of tricycle configuration.

The engine was originally intended to be the Swedish STAL Dovern RM4, but as it was not ready by the time the prototypes were completed. The Svenska Flygmotor RM6A, a Swedish version of the Rolls-Royce Avon, was the used in the Lansen. The afterburner was of Swedish design. The air intakes for the engine were located at both sides of the fuselage, forward of the wing root and cockpit.

Radar

The Lansen is among those first designs implementing onboard radar. The radar array was a PS-431/A based on the French design that worked in coordination with the anti-ship Rb04C missile, one of the first “fire and forget” missiles. As not all the squadrons were equipped with radar, and usually only one aircraft of the group would carry a navigator, the Lansen  equipped with both radar and a navigator would be the leader of the group guiding the other aircraft to the target. The radar would work in tandem with a Saab S6 computerized fire-control system, a Hughes AN/AAR-4 infrared search & trach (IRST) sensor, with the radar gunsight indicating to the pilot when there would be an optimal firing solution (these systems were mostly equipped in the J32B). The S32C was equipped with a radar warning receiver, and the J 32E was equipped with jamming devices instead of the radar in the nose. All aircraft were equipped with Saab ejection seats for the crew.

Weaponry

An RB-04 Anti Ship Missile equipped on an A32A
An RB-04 Anti Ship Missile equipped on an A32A

The Lansen would carry a varied array of weaponry depending on mission and version. The basic weapons were 4 X 20 mm Bofors (or Aden M/55 30 mm) guns located at the nose, 2 Saab 304/Rb 04 anti-ship missiles or 12 or 24 unguided rockets (60, 63, 75, 135, 145 and 180 mm), and up to 12 iron-bombs (15, 50, 80, 120, 250, 500, 600 kg). it could also carry 4 Rb 24 AIM Sidewinder missiles, ECM pods, target towing pods, jamming equipment, cameras, and chaff dispensers.

A Versatile Advanced Aircraft and Potential Nuclear Warrior

Saab J32E - 32512
Saab Lansen J32E – 32512

The Lansen was a large airframe providing a versatile platform to carry a variety of different arms depending up on mission.  Along with the Saab AJ 37 Viggen, the Lansen was a contender to carry nuclear weapons as a deterrent to protect the region, but ended up never being utilized in this role. It would have been interesting to see how a nuclear-armed version of the Lansen might have worked. But even if the Lansen in the end was not a nuclear warrior, it could boast of having a very advanced capability thanks to its design process, which was the first to be designed using a computer. Furthermore, it is among the first post-war designs to have incorporated its own radar, in addition to being among the first operational swept back wing designs.

Variants

  • A 32A – The ground attack and maritime strike version of the Lansen, and the basic one. Armed with four Bofors 20mm guns on the nose, with a special device to deflect the empty casing from entering the air intakes. The fuel tank nose was also protected with a neoprene cover to protect from the casings impact. The aircraft could also carry one of the first “fire and forget” missiles, the anti-ship Rb04/Saab 304 missile. It could also carry bombs and rockets of varied calibres and payload. This version was intended to carry the nuclear weapons developed by Sweden, should it nuclear programme was not cancelled by the 60’s. Remained in service until 1978. 287 delivered.
  • J 32B – All-weather fighter version, mainly used in adverse climate conditions and at night. Armed with four 30mm Aden cannons with the casing being retained, sparing the protective measure implemented on the J 32A. 4 Air to air Rb24/ AIM 9 Sidewinder missiles and 75 m/57 mm rockets were also part of this version’s armament, all being fired by radar sighting. There was a radar display for the pilot and not exclusively for the navigator, allowing targeting without visual thanks to the fitted IR sensor (AN/AAR-4) on the wing. Remained in service until 1973. 118 delivered.
  • S 32C – Maritime surveillance and photo reconnaissance version. Fitted with a PS-432/A radar with longer instrumented range, and four cameras (SKa 17 and SKa 18), latter, SKa 23, SKa 15 and Jugner FL S2 cameras were fitted. All the cameras were for low, high and night takes. Twelve additional British 75 kg photo flash bombs were also used, mainly on the wings. Chaff dispensers and RWR gear – to give visual and aerial warning – were installed. In service until 1978. 44-45 delivered.
  • J 32D – Target towing version modified from six J 32B airframes. Remained in service until 1997. 6 delivered.
  • J 32E – ECM version from modified 15 J 32B. Also tasked with ECM warfare and ECM training. The radar was replaced by a G24 radar-jamming device against ship and land-based radars, and two chaff dispenser were incorporated. It also carried 120kg dummy bombs.  Remained in service until 1997. 15 delivered.
  • J 32AD – A proposed daytime fighter version purposed to replace the J29 Tunnan. It would have been a single seat fighter with four 20 mm guns and a fifth 30 mm gun, all located on the nose. It would have been armed also with rockets and missile but lacking a radar. Never developed and instead 120 Hawker Hunters entered in service, filling the gap between the J 29 Tunnan and the J 35 Draken.
  • J 32U – Another proposed fighter version with enhanced performance than the J 32B, with a Rolls-Royce RA 19R engine, a supplementary rocket engine, a thinner wing with 40° of sweepback, and a flying tail. Political decisions and considerations of replacing the Lansen with other types of aircraft after 8 years of service prevented this development to see the light.

Operators

  • Sweden – The Flygvapnet was the only operator of the Lansen, having this aircraft in service from 1956 to 1997. 118 airframes where of the J 32A version; 118 airframes where of the J 32B version – 6 were modified to the J 32D and other 15 were modified to the J 32E versions – and 44-45 airframes where of the S 32C version. 452 J 32 Lansen served in total with the Flygvapnet until 1997. Three Lansen remained in service by 2012 with experimental and research purposes.

 

Lansen Specifications

Wingspan 13 m / 42 ft 7 in
Length 14.94 m / 49 ft 0 in
Height 4.65 m / 15 ft 3 in
Wing Area 37 m² / 529,8 ft²
Engine 1 Svenska Flygmotor (Rolls-Royce Avon) turbofan RM6A
Maximum Take-Off Weight 13,600 Kg / 29,982 lb
Empty Weight 7,438 kg / 16,397 lb
Loaded Weight 13,529 kg / 35,273 lb
Maximum Speed 1,125 km/h / 699 mph
Range 3,200 Km / 1,988 miles
Maximum Service Ceiling 16,000 m /52,493 ft
Climb Rate 60 m/s (11,811 ft/min)
Crew 2 (pilot & navigator)
Armament
  • 4 X 20 mm Bofors or Aden0 M/55 30 mm guns located at the nose.
  • 2 Saab 304/Rb 04 anti-ship missiles.
  • 12 or 24 unguided rockets (60, 63, 75, 135, 145 and 180 mm).
  • Up to 12 iron-bombs (15, 50, 80, 120, 250, 500, 600 kg). It could have also carried nuclear bombs, in case Sweden would have continued its nuclear programme.
  • 4 Rb 24 AIM Sidewinder missiles.
  • ECM pods, target towing pods, jamming equipment, cameras, and chaff dispensers

Gallery

Saab J32E Lansen - 32620 - Side Profile View
Saab J32E Lansen – 32620
Saab J32E Lansen - 32512 - Side Profile View
Saab J32E Lansen – 32512
Saab J32E Lansen - 32507 Side Profile View
Saab J32E Lansen – 32507
Saab Lansen J32D - 32606 Side Profile View
Saab Lansen J32D – 32606
Saab J32 Banking Maneuver
Lansen Banking Maneuver
An RB-04 Anti Ship Missile equipped on an A32A
An RB-04 Anti Ship Missile equipped on an A32A
Saab J32D Lansen - 32606
One of many still airworthy Lansens enjoying retirement at an airshow.
Saab J32E Lansen equipped for ECM
Saab J32E Lansen
Saab Lansen and Hawker Hunter in Formation
Saab Lansen and Hawker Hunter
Saab J32E - 32512
Saab Lansen J32E – 32512


Sources

Aguilera, R. D. (2015). Saab 32 LansenBergmans, W. (2011). J32 Lansen, SaabFortier, R (1997). Photo Essay Collection. Shield and Sword: Fighter Aircraft Development in the 1950s. Ottawa, Canada: National Aviation Museum.Globalsecurity.org (2012). Swedish Nuclear Weapons.Goebel, G (n.d.) The Saab 29 Tunnan & Saab 32 Lansen.Jackson, R. (2010). 101 Great Fighters. New York, NY: Rosen Publishing.Saab (2015). Saab 32 Lansen.Saab (n.d.) 1950’s.,  Sharpe, M (2001). Jets de Ataque y Defensa [Attack and Interceptor Jets, Macarena Rojo, trans.]. Madrid, Spain: Editorial LIBSA, WarbirdsUpdate (2013). The Swedish Air Force Historic Flight from Within the Cockpit. Warbirds News.Saab 32 Lansen. (2016, June 12). In Wikipedia, The Free Encyclopedia.X-Plane.org (2008). Dispersed Basing. X-Plane.org. Images: Saab Lansen 32606 by MrTMan / CC BY-SA 2.0, Saab Lansen 32512, Lansen & Hunter by Alan Wilson / CC BY-SA 2.0, Saab J32E Lansen by Leonid Kruzhkov / CC BY-ND 2.0,  RB-04 Anti-Ship Missile by AdurianJ / CC BY 2.0Plane Profile Views by Ed Jackson

 

Saab 35 Draken

sweden flag Sweden (1960)
Fighter Plane – 651 Built

A single-seat, single-engine interceptor/fighter for all-weather conditions, with low double delta wings, the Saab 35 Draken was developed in order to replace the Saab J29 Tunnan and the Saab J32 Lansen. Its first flight took place in 1955, being amongst the most advanced and remarkable fighters of its time. In 1960 it entered in service with the Flygvapnet.

Development of the Draken

Draken development started in 1949, following a requirement by the Flygvapnet for a single-seat cost-efficient interceptor with supersonic capabilities and high climbing rates, able to operate in short airstrips – or even highways, roads and unprepared runways – and easy to operate with high adaptability. As a result of both the requirements and development process, the result was a double-delta winged fighter that became the first European supersonic fighter, and also a high performance air-defence asset for Sweden. And on a similar fashion as the JAS 39 Gripen and JAS 37 Viggen, it was required the Draken to be serviced, refuelled and armed up to ten minutes by untrained ground personnel. A brake parachute was incorporated to reduce landing distance. Interestingly, a prototype was built expressly to test the double-delta wing concept: such was the Saab 210 ‘LilDraken’.

J35J in Flight - Swedish Air Force
J35J in Flight – Swedish Air Force

The Draken is also a product of the needs from a neutral nation willing to keep its neutrality, and geographically placed between the two block. This reason explains the requirements, but especially its high climbing rate capabilities, so to be able to engage high-altitude bombers and fighters – namely Soviet Union bombers and fighters. It also explains the need for STOL capacities, as the Flygvapnet was implementing a system of dispersed bases, asking for highways and roads to be used as airstrips from where the aircraft could be operating, and also to reduce damage and increase survival in case of attack.

Its very unique and remarkable double-delta wing design is also explained by the technical abovementioned requirements, which gave the aircraft very good high and low speed performances. This design made the Draken capable of executing the “Cobra” manoeuvre, and also to stand well against more recent designs, as air exercises in Austria evidenced. During development it was able to unintendedly exceed Mach 1 on its first afterburner flight. It could also sustain a force of 10G turning force. And it also had a safety feature, with the introduction of a ram turbine, placed under the nose, to provide emergency power.

Despite being conceptualized as an interceptor, it performed well in dogfights and was able to undertake ground attack, training, and reconnaissance missions as well. And it proved to be a very tough and resistant design, as it is among the few jet fighter designs to be in service for 50 years. Austria, Denmark, Finland, Sweden and US National Test Pilot School were the operators of the Draken.

The design was so unique that, in fact, the Draken was studied for the design and development of the F16XL experimental prototype.

Between 600 and 650 Draken were built, serving with the Flygvapnet until 1998, with the Finnish air force until the year 2000, the Danish air force until 1993, and the Austrian air force until 2005. The Draken also flew with the Flygvapnet ‘Acro Delta’ acrobatic team.

Design

The Draken is designed as a tailless middle double-delta wing fighter, with a single tail and a single engine (A Volvo Svenska Flygmotor RM6C, bestowing a maximum speed of 2125 km/h / 1,317 mph). Its double-delta wings allow good high and low speed performances. It also provided good fuel and armament capacity. The engine air inlets are located mid-wing at each side of the cockpit, featuring a characteristic egg shape.

Considered an easy-to-fly platform, yet not suitable for untrained pilots given the high sensibility controls, and being prone to ‘superstalls’ as a very stable platform with good low flight.

Although the avionics were in principle basic, the radar was a very sophisticated one – A PS-02/A based on the French radar Thompson-CSF Cyrano – integrated with an Ericsson version of a radar Thompson-CSF Cyrano S6 fire control system. It also incorporated VHF/UHF radio, a radio altimeter, a transponder, an IFF (Identification Friend or Foe) system, and the Swedish version of the Lear-14 autopilot. The seat of the pilot was reclined 30 degrees, similarly like the Viggen, to allow the pilot to resist G-forces. And the cockpit was fitted with air-conditioning and pressurization.

J35J Green Camouflage
J35J Green Camouflage

The engine in combination with the design, made the Draken a very manoeuvrable and fast fighter jet, with the braking parachute assisting the aircraft in the landing, reducing the distance required to reach a full stop. Earlier version of the Draken had two 30 mm Aden M/55 cannons, with later versions having only one cannon. Also some export versions kept the two cannons configuration.

An Advanced Cold Warrior

The Draken can boast not only being a radical and new design thus making it a very advanced one by the first decades of the Cold War. It was among the first fighters in incorporating an on-board radar and the earlier version of the data-link system, whose enhanced version was incorporated in the J 37 Viggen and the JAS 39 Gripen. Indeed, the Draken incorporated the STRIL 60 ground-control network that enable Draken pilots a firing guidance through the on-board instruments, being the system also capable to resist electronic jamming. Aside the fact of being the first European supersonic jet fighter, the Draken was the first fighter to have STOL capacities, and it was an aircraft that gathered valuable intelligence by producing photographic material of many new Soviet aircraft during the 70’s and 80’s. It also had a superior service ceiling in comparison with fighters of its times. Being a very resisting and long-endurance fighter, many pilots of the Draken stated that it was able to take on much newer designs.

Variants

  • J 35A – The first version of the Draken. Capable of performing fighter tasks. A small retractable wheel was placed on the rear fuselage as the angle of the nose was required to be elevated during landings to stop the airplane. But the wheel was also placed as the fuselage was enlarged, as the EBK 66 afterburner was incorporated. This version had 2 Aden 30mm cannons, installed on each engine air take, 2 to 4 Rb 24 (Swedish version of the AIM-9B Sidewinder missile) and a central fuel tank or an additional Rb 24. The afterburner installation allowed the Draken 35A to carry Bofors 135mm rockets (up to 12) in rocket pods. This version had basic avionics, being upgraded with the SB6 fire-control system, which included an infrared search and track sensor (IRST). 90 aircraft produced.
  • J 35B – Interceptor and fighter version. Its development began in 1956, before the J 65A was developed. It initially performed training task until better engines and avionics were available. This model then incorporated the air-to-ground STRIL 60 system, and new radar and fire-control systems that enhanced collision course interceptions. It had an ejection seat that allowed the pilot to eject at zero altitude. This version was armed with two 75mm Bofors cannons, folded-fin air-to-air unguided rockets, and for ground-attacks, 135mm rockets. 73 produced.
  • Sk 35C – Trainer version. Two-seat aircraft build upon J 37A airframes, being exported to Denmark and Finland. The second section was raised for the instructor’s place – being located right behind the pilot/student – and fitted with a 3D stereoscopic periscope. Upgraded with afterburners and improved avionics. The tail section was shortened, and the aircraft could be easily re-modified to its J 35A version if necessary. 25 delivered.
  • J 35D – Fighter version, equipped with a better engine – a Svenska Flygmotor RM6C – that made this version the fastest (up to Mach 2), which allowed increased payload, but also meant increasing fuel capacity. Its avionics were also upgraded, receiving a Saab FH-5 autopilot, an Ericsson PS-03 radar coupled with a Saab S7A fire-control system and a new ejection seat, replaced latter with a seat that allowed ejection on zero/zero conditions. 120 delivered.
  • S 35E – Reconnaissance version. It was unarmed but equipped with ECM measures. Fitted with seven cameras: a vertical-looking camera; a forward-looking camera on the nose; a downward/vertical looking with wide-angle camera and two sideways-looking cameras; and two long focal length vertical cameras. A downward-looking periscope and a voice recorder were fitted to allow the pilot to aim the cameras and make comments on the imagery. Latter improved with afterburners, chaff dispensers and two radar alerts, and the ability to carry on the central pylon a night-time Vinten Blue Baron multisensory night photography device. 60 delivered.
  • J 35F – Fighter version. It had improved avionics and electronics, such as integrated radars, radios, aim, infrared target seekers, and missile systems. In fact, it had the STRIL 60 incorporated. It was the version with enhanced armament, such as two semi-active radar homing Rb 27 AAM missiles, and two Rb 28 or Rb 24 AAM missiles. As a result of the new avionics, the second 30 mm cannon was supressed. Used by 18 squadrons in the Flygvapnet. 208 delivered.
  • J 35F2 – A J 35F fitted with a Hughes Aircraft Company N71 infrared sensor.
  • J 35J – Fighter version that kept the Draken in the inventories of the Flygvapnet, co-operating with the J 37 Viggen. It has six pylons, which increased the payload. It incorporated enhanced fire-control systems, infrared sensors, radar, altitude warning systems, navigation systems, IFF and modernised cockpit electronics. It also had a slightly improved RM6C engine that provided more speed. 76 delivered.
  • 35H – Proposed export version for Switzerland. None built or delivered
  • 35XD – Export versions for Denmark. It comprised the F-35 strike aircraft, TF-35 two-seat trainer and the RF-35 reconnaissance jets. Overall the 35XD were the heaviest aircraft of the Draken family, as they were optimized for strike missions. 51 delivered.
  • 35XS – Export version for Finland, some of which were locally assembled by Valmet under license in Finland. The received/assembled aircraft were the interception, fighter-bomber and training versions. 48 delivered.
  • 35BS – Used J 35B bought by Finland
  • 35FS – Used J 35F bought by Finland
  • 35CS – Used Sk 35C bought by Finland.
  • 35Ö – Version for Austria. Used J 35Ds that were refurbished and modernised by Saab, with extra 1000 flying hours, radar warning receivers, the radar of the J 35D, and chaff dispensers. Like the earlier version of the Draken, it was armed with the two 30 mm Aden cannons. 24 delivered.

Operators

  • Sweden – The Flygvapnet had 544 Draken: 90 J 35A; 73 J 35B; 25 Sk 35C; 120 J 35D; 60 S 35E; 208 J 35F; and 76 J 35J. Many were upgraded or modified airframes, so the number is an approximation. Many were sold to other countries.
  • Austria – The last exporter of the Drakens. The Österreicher Luftstreitskräfte received 24 J 35Ö – ex-Swedish J 35D – to replace the J 29F Tunnan in 1987. Initially many Draken (5 Sk 35C) remained in Sweden for training purposes, being replaced later by a simulator. The Austrian Draken were originally armed with two 30mm Aden cannons, as AIM missiles were restricted by a treaty after WWII. But as the crisis escalated in former Yugoslavia by 1993, deeming that cannons were not enough to protect the airspace, Austria acquired AIM 9P3 and AIM 9P5 Sidewinder missiles from the US and equipped them on the Draken.
  • Finland – The second exporter of Drakens, receiving 12 all-weather J 35XS interceptors, 7 ex-Swedish J 35BS, 24 ex-Swedish J 35FS and 5 ex-Swedish Sk 35CS, all to serve with the Suomen Ilmavoimat. Most of the received aircraft were delivered in kit form and assembled by Valmet in Finland, and had also two Aden 30 mm cannons. Finland used the Draken as interceptors and fighter-bombers, and retired them in 2000.
  • Denmark – The first country in exporting the Draken, with units being received in 1970. As the original version was the least favoured during the competition for a new Danish fighter, Saab created a new version (J 35XD), based on the J 35F. the structure was strengthened in order to allow more payload – 9 reinforced pylons – with simultaneous use possible. The landing gear was reinforced with an added arrestor hook, and had two Aden 30 mm cannons, as well as extra fuel capacity. Being a European cost-effective platform, plus the improvements, made the Kongelige Danske Flyvevåben to choose the Draken. 20 A 35XD ground attack fighters (denominated F35), 30 S 35XD reconnaissance (denominated RF35), and six Sk 35XD training (denominated TF35) were purchased. 7 additional aircraft were purchased to be cannibalized. Danish training and reconnaissance versions were fitted with cannons and pylons to carry weapons, thus having secondary combat capabilities. 5 further Drakens (TF35) were purchased. Receiving upgrades in the following years, the Draken were retired from Danish service in 1993.
  • US National Test Pilot School – Operated 6 Drakens, formerly Danish Air Force jets training and reconnaissance versions.

Draken Specifications

Wingspan 9.42 m / 30 ft 10 in
Length 15.20 m / 49 ft 10 in
Height 3.8 m / 12 ft 7 in
Wing Area 49.22 m² / 529.8 ft²
Engine 1 Svenska Flygmotor Turbofan RM6B
Maximum Take-Off Weight 10,089 Kg / 22,200 lb
Empty Weight 6.590 kg / 14,500 lb
Loaded Weight 16,000 kg / 35,273 lb
Maximum Speed 1,900 km/h / 1,200 mph
Range 3,250 Km / 2,020 miles
Maximum Service Ceiling 18,000 m /59,100 ft
Climb Rate 200 m/s ( 12,000 m/min / 40,000 ft/min )
Crew 1 (pilot)
Armament • 1 Aden 30mm Cannon
• 6 hardpoints that could allow 1700 kg of payload. A pod for a 135mm Bofors M70 rockets; air-to-air Rb 24, Rb 27 or Rb 28; external fuel tank; iron bombs; cameras.

 

Gallery

Saab J35J Draken - 35556 - Side Profile View
Saab J35J Draken – 35556
Saab 35Ö Draken - 351408 - Side Profile View
Saab 35Ö Draken – Austrian Air Force
Austrian Air Force Saab J35Oe Draken 351421
Saab J35Ö Draken – Austrian Air Force

Sources

Ängelholms Flygmuseum (n.d.). Flygplan J65 Draken Operational History.Boyne, W (December 2011). Airpower Classic. J35 Draken. Air Force Magazine, 94 (12), 68.Cpt. Moore, V. (2005). A Dragon’s Farewell. Warbirds, 28 (8), 12-16., Guerras del Siglo XX (1994). Guerras del Siglo XX, Aviones. Madrid, Spain: Editorial Altaya., Liander, P. (1999). Draken pensionerad. FlygvapenNytt, (1), 24-27.Martin, G. (2012). The Draken: One of Sweden’s finest fighters. Aircraft Information.Piccirillo, A. C. (2014). Elegance in Flight. Washington, DC: National Aeronautics and Space Administration., Sharpe, M (2001). Jets de Ataque y Defensa [Attack and Interceptor Jets, Macarena Rojo, trans.]. Madrid, Spain: Editorial LIBSA (Original work published in 2001)., WarbirdsUpdate (2013). The Swedish Air Force Historic Flight from Within the Cockpit. Warbirds News., Saab 35 Draken. (2016, April 2). In Wikipedia, The Free Encyclopedia.Winchester, J. (2012). Jet Fighters: Inside & Out. New York, NY: Rosen Publishing.X-Plane.org (2008). Dispersed Basing. X-Plane.org., Images: Draken in Flight by Alan Wilson / CC BY-SA 2.0, J35J Draken Exhibit by Alan Wilson / CC BY-SA 2.0

 

Saab Viggen - Banking

Saab S37 Viggen

sweden flag Sweden (1971)
Multirole Fighter Plane – 329 Built
The Saab Viggen is a single-seat, single-engine fighter with a low double delta wing and with two canards equipped with flaps, intended to replace the Saab J35 Draken. Its first flight took place in 1967. When it entered service in 1971 with the Flygvapnet, the Swedish Air Force, it was the most advanced fighter jet in Europe until the introduction of the Panavia Tornado (1981). It was also the first canard-designed aircraft to be produced in a large quantity.

Development of the Viggen

Development for the Viggen began in 1952, with the development period of 1958 to 1961 being crucial for the airplane, as it was decided to integrate the System 37 as standard arms control. This system would end integrating radar, air-defence screens (Stril 60), and computers, and the Viggen were intended to be the platform for such system. This system made the aircraft extremely advanced in comparison to other designs. Along with the Draken it was the precursor to the advanced datalink system the Gripen would later incorporate. Like most of Swedish designs, it also had short taking-off landing (STOL) capabilities (500 meters), thanks to canards, a thrust reverser – that allowed the aircraft to reverse on the ground, and an afterburner to facilitate short take offs. The engine and the remarkable HUD capability also assisted in landing operations.

Interestingly, it can withstand a force of 12G, but operational limit is 7G. It is also a multirole aircraft. However the multirole ability resides more in a basic airframe giving way to different versions: fighter-bomber, attack, tactical reconnaissance, sea reconnaissance, training, and fighter. Given the specific defence conditions of Sweden, the aircraft was required to be easily maintained and serviced by airmen with little training, within a time of 10 minutes.

329 Viggens were built, and served in the Flygvapnet until 2005. Noteworthy to mention that the Swedish Air Force was the main and only user of the Viggen. Agreements with the United States provided technology enough to increase the performance of an already advanced fighter, making it one of the most advanced during most of its service life.

Design

Saab Viggen - BankingThe Viggen is designed as a low double delta wing fighter, with a single tail and a single engine (A Volvo Turbofan Flygmotor RM8B, the most powerful installed in a jet fighter upon its introduction, achieving a maximum speed of Mach 2. It has canards with flaps that provide lift for both flight and taking-off and landing. Assessed as a very stable platform with good low flight, the canards and the combination of the engine, the thrust reverser, the HUD, and the afterburner allows for STOL capabilities (Taking off: 400 mts/ 1310 ft; landing: 450-500 mts/1640 ft).

The wings were provided with dogtooth at the attack border, in order to improve stability at high incidence angles. The structure was built with aluminium with a honeycomb structure, with the rear being totally of aluminium, allowing the Viggen to withstand the stress of no-flare landings, while the vertical stabilizer, or tail, was made tall given the requirements the large anti-ship missiles existing back then imposed on the design. It has a “hump” on the dorsal area to reduce drag. An interesting feature of the tail is that it can be folded, so to enhance the storage in underground and/or smaller hangars. Earlier version of the Viggen did not have an internal cannon, as it was considered by the days a close-range combat was not necessary, an approach that also affected other designs, such as the American Phantom F4. Further variants incorporated an internal cannon. The pilot seat was angled by 19 degress so to allow the pilot to resist better G forces.

A Cold Warrior with Digital Features

Saab Viggen - CockpitThe Viggen was intended to be a single pilot fighter, making the introduction of advanced avionics a requirement as there would be no navigator. As a result, the Viggen incorporated the CK 37 (Centralkalkylator) computer, the first airborne computer with integrated circuits, and that even remained in service with the Flygvapnet fleet of Viggens until the early years of the 21st century. During the development of the Viggen’s electronic components, operational aspects like vibration, exposure to strong forces and even crashes were considered, resulting in a very strong computer with a strong hardware capable of resisting crashes while keeping valuable information of the aircraft. It was also a very valuable computer for the Viggen, as it was able for assisting the pilot and aircraft missions and control of the aircraft.

Another important avionics element of the Viggen, working in tandem with the integrated computers, was the radar, an Ericsson PS-37 X radar. This radar was able to perform air-to-ground and air-to-air telemetry, search, track, terrain avoidance and cartography tasks. The further versions of the Viggen received enhanced avionics and electronic/digital components, enhancing their capabilities and mission performance.

Guardian of Neutrality

The Viggen is a pure product of the times it was designed and the context in which Sweden was a neutral country forced to increase its military power in order to safeguard its neutrality during the heated days of the Cold War. As Sweden was a close neighbor to the Soviet Union, many incidents between the two nations took place. Those incidents prompted Sweden to have an alert service, with round-the-clock radar surveillance, fighters and attackers on high readiness for combat, among other measures. The design therefore was intended to meet the defence needs of Sweden and the missions of the Flygvapnet.

Saab Viggen - TakeoffA first requirement was for the Viggen to have STOL capabilities, so to be able to operate from damaged runways – or runways and highways – and also from secondary airfields. The aim of such operational conditions was to increase the survival of air assets and to difficult the destruction, blocking or dispersion of such assets by an aggressor. A second requirement was the Viggen to be serviced, refuelled and rearmed in less than ten minutes by untrained personnel. This, considering that Sweden’s particular defence conditions required small and dispersed air and field bases, having little personnel and facilities. In fact, and thanks to this system, the Viggen was able to execute up to 11 sorties within a period of 24 hours. In addition, the Viggen became the main asset of Swedish air defence, intercepting, patrolling, and monitoring Soviet and Western activities and flights. This explains the multi-role capacities of the Viggen, or at least to have served as a basis for different versions using the same airframe. It also allowed Sweden to demonstrate its readiness. During the S-137 Soviet submarine incident, the submarine ran aground on the Swedish archipelago and Soviet surface vessels closed in on the Swedish coast to attempt a rescue, armed Viggens were put into the air so to ward-off the Soviets. Also, with the routine of the American SR 71 Blackbird path known, the Viggen was able to get radar-lock on the SR71 despite the jamming measures of the reconnaissance plane and thanks to coordination with ground-based radars. It is the only aircraft that managed to lock onto the SR 71.

Variants

  • AJ 37 – An all-weather attack aircraft with air-to-air secondary capacity. Considered outdated, it lacked a gun, but had increased bombing precision thank to its HUD and Weapons Aiming Computer System. Armed with rockets and iron bombs for strike missions, and Saab 305/Rb 05 or Sidewinders and 30mm cannon pods for air-to-air. It also had anti-ship capabilities thanks to the Saab 304 anti-ship missile. 108 delivered.
  • Sk 37 – Training version, with a second cockpit and the avionics and fuel removed, also lacking a radar array. It had instead of the internal fuel tank, a permanent fuel tank under the belly. It also had a shorter range. The second cockpit has two periscopes to provide forward view. It was tasked with providing pilots conversion and supersonic training. It also had secondary combat capacities. 10 were converted to electronic warfare trainers (SK 37E). 17 delivered.
  • SF 37 – All-weather reconnaissance version and intended to substitute the S35E. The nose had a peculiar form thanks to the fact that the recce equipment was placed there, with seven cameras. On the hardpoints further reconnaissance equipment was placed. One camera can take infrared pictures, two vertical cameras can take shots for high-altitude, and four cameras for low-altitude shots. It had the same armament as of the JA 37 interceptor version yet lacking of radar. 28 delivered.
  • SH 37 – Single seat version fitted for sea surveillance and attack/anti-ship roles, armed usually with the Saab 305 anti-ship missile and other ground-attack weaponry. It could also carry Sidewinder missiles for self-defence. 28 delivered.
  • JA 37 Jaktviggen – All-weather interceptor version of the Viggen, powered with a Flygmotor RM8B. Incorporated an internal 30 mm Oerlikon cannon, and could operate AMRAAM, Sidewinder or Rb71 Sky Flash missiles. Armed also with radar and infrared homing missiles. It also had upgraded avionics, such as a long-range Ericsson UAP-1023 pulse Doppler radar, enhancing target acquisition, and new computers that enhanced as well the aircraft performance. In fact, there is a coupling of radar gunsighting with the autopilot, presenting a lock information to the pilot’s HUD while increasing the cannon lock thus reducing the workload for the pilot. It also had an inertial navigation system. Furthermore, it provides tracking for land, air and sea-borne targets while resisting to ECM attacks. Some were upgraded with airframes, avionics and software modified for international duties (JA 37C, JA37D, and JA37DI) 149 delivered.
  • Saab 37 Eurofighter – Proposed replacement for NATO F-104 Starfighter. None built.
  • Saab 37 X – Proposed version to be exported to Norway. None built.

Operators

  • Sweden – The Flygvapnet has 329 Viggens, 108 of which are AJ 37, 17 were Sk 37, 28 were SF 39, 28 were SH 37, and 149 were JA 37.

Viggen Specifications

Wingspan 10.6 m / 34 ft 9 in
Length 16.40 m / 53 ft 9 in
Height 5.6 m / 18 ft 4 in
Wing Area 46 m² / 500 ft²
Engine 1 Volvo Flygmotor Turbofan RM8
Maximum Take-Off Weight 20,500 Kg / 45,194 lb
Empty Weight 11,800 kg / 26,014 lb
Loaded Weight 16,000 kg / 35,273 lb
Maximum Speed 2,125 km/h / 1,320 mph
Range 2000 Km / 1,242 miles
Maximum Service Ceiling 18,000 m /59,100 ft
Climb Rate 203 m/s ( 12,000 m/min / 40,026 ft/min )
Crew 1 (pilot)
Armament • 1 Oerlikon KCA 30mm cannon (JA 37)
• 7 hardpoints that could allow 6000 kg of payload. A pod for Aden 30 mm cannon; 135mm Bofors M70 rockets in pods for six rockets; air-to-air Saab 305/Rb 05, Rb71 Sky Flash, AMRAAM or Sidewinder missiles; air-to-surface or Maverick missiles; Anti-ship Saab 304; 120 kg iron bombs.

Sources

Anrig, C. F (2005). Flygvapnet, The Swedish Airforce in an Era of Transition. Air Power Revue, (4) 36-44.Ängelholms Flygmuseum (n.d.). Flygplan J37 Viggen., Berger, R (Ed.). Aviones [Flugzeuge, Vicenç Prat, trans.]. Colonia, Alemania: Naumann & Göbel Verlagsgessellschaft mbH., Boyne, A (July 2014). Airpower Classic. JA37 Viggen. Air Force Magazine, 97 (7), 76.Lemoin, J (2002). Fighter Planes. 1960-2002., Groebel, G (2016). The SAAB 37 Viggen., Jiewetz, B (n.d.). Central Computer for aircraft Saab 37, Viggen. DATASSABs Vänner.SAAB (n.d.). Saab 37 Viggen. Brochure., Sharpe, M (2001). Jets de Ataque y Defensa [Attack and Interceptor Jets, Macarena Rojo, trans.]. Madrid, Spain: Editorial LIBSA (Original work published in 2001)., WarbirdsUpdate (2013). The Swedish Air Force Historic Flight from Within the Cockpit. Warbirds News., Saab 37 Viggen. (2016, May 1). In Wikipedia, The Free Encyclopedia., Gunston, Bill and Mike Spick. Modern Air Combat: The Aircraft, Tactics and Weapons Employed in Aerial Warfare Today. New York: Crescent Books, 1983. Images: Saab Viggen Banking by Alan Wilson / CC BY-SA 2.0, Saab Viggen Intake by Houser Wolf / CC BY-ND 2.0, Saab Viggen Gear by Alan Wilson / CC BY-SA, Saab Viggen Takeoff by Alan Wilson / CC BY-SA, Saab Viggen Cockpit by Per80 / CC BY-SA 3.0, Saab Viggen Engine Inspection by Rune Rydh / Flygvapenmuseum / CC BY 4.0

Gallery

SAAB Gripen Armed In Flight

Saab J39 Gripen

sweden flag Sweden (1997)
Multirole Fighter Plane – 247 Built
A light single-engine multirole fighter, with a delta mid-wing and canard configuration. This aircraft has a fly-by-wire flight controls. Purposed with replacing the Saab 35 Draken and Saab J 37 Viggen AJ, SH, SF and JA versions in service with the Flygvapnet (the Swedish Air Force), and in service since 1995. Its development began in the late 70’s, with the aircraft intended to perform the same missions of the models it was replacing. As a result, the Gripen is capable of executing missions as fighter, attacker, and reconnaissance, being also a cheap yet well-powered and highly manoeuvrable jet, capable of integrating well with the Flygvapnet communication and infrastructure systems. It is also a platform with good upgrading capacities. Another special feature of this model is the short take-off and landing (STOL), alongside its agility and responsiveness at subsonic speeds, low induced drag and good supersonic performance. A product of Swedish innovation and defence needs, allowing Sweden to maintain its neutrality during the Cold War, the aircraft’s STOL characteristic came as a result of the policy of using highways and roads as airstrips, in order to reduce the potential damage to Flygvapnet air assets in case of attack, and to maintain air defence capacity. It was also intended to be an easy maintenance airplane, with conscripts having basic technical knowledge being able to do maintenance works. This increases the aircraft’s service life.

Design

The Gripen is designed as a mid-delta wing fighter, with a single tail and a single Volvo Flygmotor RM 12 engine. It has canard winglets that also serve as complement for the two aerodynamic brakes located at the sides of the rear fuselage. The combination of the canards and the delta wing design allows the Gripen to fly at 70-80 degrees of attack angle, allowing also STOL capabilities (800 mts/2600 ft airstrip). Its purposed aerodynamic instability is compensated with a fly-by-wire technology that bestows the Gripen with considerable fly characteristics. The engine also plays its part in shaping the Gripen characteristics, along with some additional features. The double digital control and double ignition allows the pilot and the aircraft to be safe in case of emergency. The engine itself is reinforced to withstand the impact of birds or foreign objects. The radar – an Ericsson pulse-Doppler – allows the Gripen to have powerful and sharp ‘eyes’, as it allows multiple target track and beyond visual range (BVR) for air-to-air; mapping ground and surface target indication and tracking for air-to-ground; and sea surface search and tracking.

The Digital Era

SAAB Gripen Parked

The JAS 39 has a Tactical Information Data Link System (TIDLS) digital network which provides the Gripen with a tactical advantage: to distribute and share radar and sensors information with up to 4 aircraft within a radio of 480 kms (300 miles), enabling tactical combat information and situation awareness. It also provides any pilot information about the position, speed, missile load, heading and fuel state of other Gripens. This provides also concealment to any pilot opening fire against a selected target, without revealing its position, while the launched missile – a medium-range air-to-air-missile (AMRAAM) – will be guided not only by the aircraft it was fired from, but also by the other aircraft, whose guidance can improve the missile’s accuracy. TIDLS technology however, is not a product enjoyed only by the Gripen’s development, but it is an enhanced version, as the JAS 35 Draken and JAS 37 Viggen had a similar and early datalink systems. As it is a multirole aircraft, this means it can change its mission while flying, as the pilot change the avionics and sensors in flight. Although the small size of the plane limits these capacities and payload, forcing missions to be considered before sorties, it also allows the aircraft to reduce detection by radar.

The Gripen goes to Battle 

SAAB Gripen Armed In Flight

The high adaptability and capacity of the aircraft to be easily upgraded allowed the Gripen to be modified in order to fit NATO standards, and to increase its export options. Alongside the British BAE, Saab improved and modified the Gripen so to be able to operate with NATO missiles, opening the open for the aircraft to carry more powerful missiles, and having also enhanced air-to-ground capabilities. Those modifications allowed the Gripen to support NATO intervention in Libya (Operation Unified Protector) with tactical air reconnaissance, enforcement of the no-fly zone, the arms embargo, and support for civilian protection. It was also able to receive updates and information from NATO E-3 AWACS airplanes. The Gripen performance was optimal during the operation, as it flew 570 missions, around 1770 flight hours, and delivered 2770 reports.

A Coveted Fighter

Saab Gripen Taxiing

Given its characteristics and its good relation cost/operation, the Saab JAS 39 Gripen has received the attention of many countries that expressed their interest in the fighter. Countries like Argentina, Austria, Belgium, Botswana, Bulgaria, Colombia, Croatia, Ecuador, Estonia, Finland, India, Indonesia, Kenya, Latvia, Lithuania, Malaysia, Mexico, Namibia, Peru, The Philippines, Portugal, Serbia, Slovakia, Slovenia, Uruguay, and Vietnam, all could become potential operators of the Gripen.

Variants

  • JAS 39A – The basic and first version entering in service with the Flygvapnet, later upgraded to the C version.
  • JAS 39B – The two-seated variant of the JAS39A, purposed for training, specialised missions and flight conversion, with the cannon and the internal fuel tank removed to allow the second crew member and life support systems.
  • JAS 39C – A NATO-compatible version with overall enhanced capabilities, as well as in-flight refuel.
  • JAS 39D – The two-seat version of the JAS 39C.
  • JAS NG – An improved version of the Gripen, having a new engine (The General Electric F414-400), a new radar (RAVEN ES-05 AESA), and increased payload and fuel capacity. Its development was undertaken through a partnership with Switzerland. A product of the changes brought by the end of the Cold War, as airbases were closed with fighter units being reduced, as well as the closure of the road base system for take offs and landings. But it is also a product of the new assessed threat Sweden could be facing, which required a new fighter with extended range, increased weapons, enhanced electronics, fighter communications (with satellite) and Electronic Warfare (EW) capability.
  • JAS 39E– Single seat version derived from the JAS NG.
  • JAS 39F – Two-seat version derived from the JAS 39E.
  • Sea Gripen – Proposed carrier version of the NG.
  • Gripen UCAV – Proposed unmanned combat version of the JAS 39E.
  • Gripen EW – Proposed electronic warfare version derived from the JAS 39F.

Operators

  • Brazil – 28 Gripen JAS 39E and 8 Gripen JAS 39F on order, with options of assembling some locally, while the Brazilian Navy is interested in the Sea Gripen for use on its single aircraft carrier. Brazil could export Gripen into the regional market. There is a provision for joint development with Sweden.
  • Czech Republic – 14 Gripens on lease (12 JAS 39C and two JAS 39D) until 2027 and to replace the existing Mig 21 fleet. given the current tensions between the West and Russia, Czech Republic government considered leasing 6 more Gripens. Gripen have had a good use by the Czech Air Force, with membership of the NATO Tiger Association, awarding the Tiger Meet Silver Tiger Award as ‘Best Squadron’. Gripen from Czech Republic also take part in NATO Baltic Air Policing, while performing homeland defence duties at the same time.
  • Hungary – 12 Gripens on a lease-and-buy basis (11 JAS 39 C and one JAS 39D) until 2022. Two Gripens lost in crashes. Hungarian Gripens have been taking part of NATO Baltic Air Policing since 2015.
  • South Africa – 26 Gripens are in service with the South African Air Force (17 JAS 39C and 9 JAS 39D), facing restricted operation given lack of qualified pilots and financial resources. However, South African Gripens enjoyed a local EW development – in cooperation with Israel – and datalink, as well as radar weather mode. The Gripens saw action when securing South African airspace during the FIFA 2010 World Cup, supporting South African troops in the Democratic Republic of Congo in 2013, and taking part in Nelson’s Mandela funeral.
  • Sweden – The Flygvapnet has 156 Gripen, 50 of which are JAS 39A, 13 are JAS 39B, 60 are JAS 39C and 11 are JAS 39D. Two (a JAS 39C and a JAS 39D) were lost in accidents.
  • Thailand – 12 Gripens (8 JAS 39C and 4 JAS 39D) serve with the Thai Air Force, where eventually 6 more Gripen would be bought. As these Gripen operate over the Andaman Sea and Gulf of Thailand, they have anti-ship capacities.
  • United Kingdom – Operated by the Empire Test Pilots’ School, with 3 JAS 39B, with training and testing purposes.

Gripen Specifications

Wingspan  8.4 m / 27 ft 7 in
Length  14.10 m / 46 ft 3 in
Height  4.7 m / 14 ft 9 in
Wing Area 30 m² / 323 ft²
Engine 1 Volvo Flygmotor turbofan RM12
Maximum Take-Off Weight 14000 Kg / 30,900 lb
Empty Weight 6800 kg / 15,000 lb
Loaded Weight 8500 kg / 18,700 lb
Maximum Speed 2450 km/h / 1522 mph
Range 3250 KM / 1,983 miles (with external drop fuel tanks)
Maximum Service Ceiling 16000 m /52,500 ft
Climb Rate 100 s from brake release to 10 km altitude / 180 s approx to 14 km
Crew 1 or 2
Armament • 1 Mauser BK 27 27mm cannon
• 6 hardpoints that could allow 6 air-to-air missiles, 4 air-to-radar missiles, 4 air-to-surface missiles, 5 smart bombs, 2 anti-ship missiles, 5 bombs, 2 stand-off weapons, 2 ECM Pods, 2 recce Pods, 1 FLIR/LDP Pod, 2 AACMI Pods, and 3 fuel tanks

Gallery

Sources

Berger, R (Ed.). Aviones [Flugzeuge, Vicenç Prat, trans.]. Colonia, Alemania: Naumann & Göbel Verlagsgessellschaft mbH. , Hellenius, B (March 2014). Griffin Takes Wing. Air Forces Monthly, (312), 50-65. , SAAB (March 2016). Gripen brochure. , SAAB (n.d.). Gripen-Advanced Weapons Flexibility. , SAAB (n.d.). Gripen dimensions. , Singh, V (May-June 2014). The Gripen forges ahead – in ‘Super’ mode. VAYU Aerospace & Defence Review, (3) 61-65.  , Sharpe, M (2001). Jets de Ataque y Defensa [Attack and Interceptor Jets, Macarena Rojo, trans.]. Madrid, Spain: Editorial LIBSA (Original work published in 2001). , Wikipedia:Saab JAS 39 Gripen Images: SAAB Gripen Taxiing by Airwolfhound / CC BY-SA 2.0 ,  SAAB Gripen Parked by Milan Nykodym / CC BY-SA 2.0 , SAAB Gripen Armed in Flight by AereiMilitari.org / CC BY-NC 2.0