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.

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.

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.

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.

Gallery

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 2.0, Side Profile Views by Ed Jackson – Artbyedo.com