HISTORY, DEVELOPMENT AND DESIGN
In the aftermath of WWII, in 1945, the world changed dramatically. Europe was under the influence of the new two super powers (USA and USSR), which had contributed drastically on ceasing the six years world conflict who paralyzed the global economy and cost countless human lifes. The bipolar soon leaded in a new undeclared war and in a new armament run, based on the saying «To be prepared for war is one of the most effective means of preserving peace». Furthermore, the WWII had clearly defined that the spearhead of future conflicts will be the air superiority. Especially, on aeronautical engineering, giant steps had been conducted, with the most important the improvement of jet engines and swept-back wings. Indeed, the Luftwaffe’s interceptor Messerschmitt Me 262 Schwalbe which introduced in the last days of the war was the first jet fighter in the world having swept-back wings. Even if it didn’t played any role on aerial combats due to its limited production, was the milestone for a new era fighters. USA, Great Britain and USSR took the lead on that technology, after having direct access on the advanced German WWII technology. On the other hand, there were some exceptions, amongst them was Sweden. Despite the fact that not having the same access on the advanced technology, Sweden managed to develop its own aerospace engineering. The Saab J 29 Tunnan «flying barrel» was the second swept-back wing jet fighter of Europe which designed and manufactured by the Swedish enterprise.
The Swedish General Staff of Armed Forces, taking into account the quick collapse of Norway and Denmark in spring of 1940, knew well that they would have the same fate if the Germans declared war against them. Since then, Swedish armed forces started to renovate, giving priority to the air force, thinking that was the key role to any future conflict. In the aftermath of WWII, the Swedish Army as well as SAAB (Svenska Aeroplan ΑΒ) engineers, realized that the jet engine propulsion was priority for the aeronautic advantages, but their access on that technology was limited. The opportunity for the new technology raised when Sweden and Britain signed in fall of 1945, the installation of the british designed, centrifugal flow, jet engine, de Havilland Goblin to the J-21 reciprocating (piston) fighter. SAAB responded initially to the Swedish Air Force (Flygvapnet) request for a Swedish made fighter jet, replacing the water cooled, 12piston, V-type Daimler Benz DB 605Β engine with the Goblin jet engine on the J-21. The modified fighter codenamed J-21R. To note here, that the letter J in the Swedish Air Force means fighter and derives from the word «Jakt». J-21R made it maiden flight in 1947, but its performance and operational features were not met the Flygvapnet standards.
However, Flygvapnet tries for the development of a new jet propulsion fighter included also the JxR Project, which was running simultaneously since 1945. JxR development was the cause for all the other piston propulsion fighter projects cancelation. Despite the fact that the J-21R was on the right way, certainly that was not what SAF was looking for, to cover temporarily its needs. To overcome this situation, SAF decided to acquire several british de Havilland Vampire F.1, which codenamed J-28Α. The first units delivered within 1947. In the meantime, SAAB [Svenska Aeroplan Aktie Bolaget) and Lars Brising’s team made serious progress on the JxR Project, presenting to Flygvapnet two designs, RX-1 and R101 known as «The Cigar». RX-1 project concerned a design similar to the British de Havilland Vampire F.1, while the R-101 was a design close to the American Lockheed Ρ-80 Shooting Star. The first design rejected by the Flygvapnet, which turned entirely to the second one. But, Ρ-80 was supplied with a turbojet engine while SAAB had the technology for centrifugal flow jet engines only. Thus, the airframe has been redesigned leading to fuselage’s increased diameter in order to fit the centrifugal engine. The new design codenamed R-1001, gaining the nickname «Tunnan» (means the barrel, cause of its fuselage shape). At the initial design which presented in October 1945, the fighter had a conventional trapezoidal wing, such as the P-80’s. In November, German aeronautical documents came to SAAB’s position through Switzerland, presenting analytically the positives and the negatives of the swept wings. Going through these documents, Swedish decided that the new fighter must have that type of wings. In the original documents, Germans referred to a swept wing of 45 degrees (sweep angle), but Swedish chose a more conservative one, having just only 25 degrees.
Lars Brising’s team, having in hand all those new factors, redesigned the fighter proposing the RM 2 Ghost jet engine and sweep angle of 25 degrees supplied with single slotted flaps. The wings were durable, but on the other hand their low thickness-swinger ratio meant that they couldn’t host any landing gear bays. Thus, the bays placed on the ventrolateral fuselage area. That modification changed the shape of the fighter, looking like a barrel. Engine’s intake placed on the center of the nose, while the rudder was synchronized with the elevators (another innovation for Europe). The wings placed approximately at the middle of the fuselage (mid wing). The cockpit designed to be at the distal area of fuselage and high up, combining with the bubble shaped canopy, offered the ideal view to the pilot.
The new design satisfied the Flygvapnet staff and the final project completed in early 1946. Both SAAB and SAF expected that the new fighter would have remarkable capabilities for that time, while its max speed estimated to reach 1000 kph (620 mph). The «green light» for the development of the new fighter (R- 1001) has been given to SAAB in February 1946.
Extensive wind tunnel testing held initially with aircraft’s model, while later a swept wing has been built (1/2 of the real) having an angle of 25 degrees and placed on a SAAB 91A Safir. Theat project started in Spring 1946 and the aircraft named Saab 201. In fall of 1946, Flygvapnet decided the construction of 3 prototypes with the codename J-29. The first conducted its maiden flight on September 1st 1948. The test pilot for this first flight of the type was an Englishman, S/L Robert A. ‘Bob’ Moore, because at that time there were no experienced Swedish pilots. Following the flight, Moore described the aircraft as being: «on the ground an ugly duckling – in the air, a swift».
The prototype was supplied with the de Havilland Ghost 45 jet engine, providing maximum thrust of 4.400lbs, something that overwhelmed the Flygvapnet’s expectations. Despite its outer barrel shape, the fighter was extremely agile and swift, while the addition of deployable leading edges (first time in history) reduced significantly its landing speed, making the aircraft ideal for short runways.
Armament was not installed in the first two prototypes, but the third carried 4x20mm automatic Bofors guns, just beneath the engine intake. Each gun had a 180 round feeding belt. According to the prototypes, another one built and flew in 1950. None of the prototypes was introduced in service with Flygvapnet.
VARIANTS
Saab J-29 was well known in SAF with the nickname «Flygande Tunnan», The Flying Barrel. In total, 661 units were produced between 1950-1956, making it the largest production run for any Saab aircraft. 224 units produced of the first variant, J-29A between 1951-1954. The first fighters delivered to Flygvapnet in January 1952. The propulsion system of J-29As was the RM 2 Ghost turbojet engine, capable of generating up to 5,000lb of thrust. The engine was built in Sweden under Svenska Flygmotor’s license.
The only modification on the J-29A was the addition of airbrakes on the wings, something that abandoned relatively quickly due to intense vibrations at high speeds. Thus the airbrakes were placed on the fuselage, in front of the landing bays.
J-29Α served until the mid ‘60s with Serial Numbers from No 29101 to No 29324. The second variant, J-29B, was a J-29A carrying bigger internal wing fuel tanks. Fuel capacity of J-29-Α was only 1.400Lt, while J-29-Β was 2.100 (50% more).
In addition, J-29-B variant used also for air attack missions and for that reason some fighters codenamed Α-29Β (Air Attack). Particularly, Α-29Β could carry on the hardpoints: 12 x 75mm (2,95in) air to air rockets, three per hardpoint; 14 x 5mm (5,7in) antitank rockets or 14 x 150mm (5,9in) HE rockets; 4 x 125Kg, 180mm (7.1in) anti ship rockets; 2 x 400 or 500Lt external drop – fuel tanks or Napalm bombs.
The production of J-29B started on March 11th 1953 and ceased in 1955, while 361 units were built having S/N from 29325 to 29685. It is noticeable that in May of 1954 a J-29Β set the world speed record flying with 997kph on a 500Km closed circuit.
Next variant was the reconnaissance Tunnan, S-29C (Spaning: Reconnaissance) which had modified nose for the fitting of 5 cameras. The guns were removed and replaced by the cameras, while an early warning radar installed in a cone on the vertical stabilizer.
Later on, engineers noticed that the cone interfered with the aerodynamics of the plane and the cone removed and the radar reinstalled in the fuselage. In total, 76 units were created with S/N 29901-29976 during 1954-1956 and served until 1970.
Although, they had the capability to use colored infrared film, due to its cost (around 1.000 USD per film) black and white infrared films used for the cameras shooting left and ahead, while cameras shooting right and ahead multicolored film were used.
In March 23th 1955 an S-29C set the world speed record flying with 900kph on a 1000 closed circuit. The previous record held by a RAF Gloster Meteor with speed of 822kmp.
In parallel, during the production of the Tunnan engines, Svenska Flygmotor planed to create the next Ghost engine version having afterburner capabilities. The new engine codenamed Ghost DGT 3, generating up to 6.175lb thrust.
The new engine installed for testing on a J-29Β fighter, receiving the code J 29D.
A modification on the wings had been approved, in order to increase the cruise speed from 0.86 to 0.89 MACH, by replacing the single slotted flaps by double slotted flaps forming a «dogtooth». The cruise speed increased without affecting at all the landing speed. The new wing installed on the J-29E variant. The prototype conducted its maiden flight on December 3rd 1953, while 29 units created after the modifications on J 29Βs fighters.
Last Tunnan version was the J-29F, carrying the new Ghost DGT 3 (RM 2Β) afterburner engine and the modified wings. Its maiden flight conducted on March 20th 1954 and 210 units were produced, coming from modifications on early variants (J–29A and J–29B). In addition, J-29F had the capability to carry the Rb2A air to air missile. Rb2A missile was a copy of the American ΑΙΜ-9Β Sidewinder, which produced by SAAB in Sweden.
OPERATIONAL HISTORY
The primal user of SAAB J-29 Tunnan was the Swedish Air Force, using the type until 1965. Since 1968 and up to 1974 used for target bowing duties, and the last official military flight was performed at the Swedish Air Force’s 50th anniversary air show.
Tunnan served at the following combat wings: F 3 Malmslatt, F 4 Froson, F 6 Karlsborg, F 7 Satenas, F 8 Barkarby, F 9 Save, F10 Angelholm, F11 Nykoping, F12 Kalmar, F13 Norrkoping, F15 Soderhamn, F16 Uppsala and F 21 Lulea.
30 Tunnans served with Austrian Air Force in the period 1961-1972. Specifically, Austria received 15 J-29F in 1961 and the rest in 1962.
Despite the fact that J-29 has the title of the first European postwar jet fighter with swept-back wings, is also the only Swedish fighter participating in combat missions under UN in Congo. In detail, in 1961 five J-29Βs deployed in Congo organized as the F 22 Congo Wing of the SAF, served under the UN surveillance. Within 1962 Congo Wing received additional 4 J-29Β and 2 reconnaissance S-29C.
Most of the missions involved attacking ground targets and reconnaissance. No aircraft were lost in action, except one that crashed during an aborted takeoff. When UN mission was terminated in 1964, some of the Swedish aircraft were destroyed at their base, since they were no longer needed at home and the cost of retrieving them was deemed excessive.
Some survivors can still be visited nowadays, especially in museums. In detail, one J-29Β (S/N 29398) and one J-29F (S/N 29575) are displayed at the SAF museum, Malmoe; one J-29F (S/N 29640) at Midland Air Museum, UK; one J-29F (S/N 29657) at the National Air and Space Museum, USA; one J-29F (S/N 29543) at Vigna di Valle Museum, Italia; one J-29F (S/N 29588) at Luftfahrt Museum, Germany.
Info: Remove Before Flight (Military), issue 3, August-September 2008.
CONSTRUCTION
The kit is a relatively old Airfix, originally comes from Heller moulds. Contains only 35 grey-blue plastic parts, has elevated paneling and few rivets. The detailing can be described as good for the scale but the fitting is even better. The clear parts are just 5 pieces, having a reasonable thickness and relatively clear plastic. The instructions are very simple but giving direct orders for the additional steps and paint procedures.
At the beginning, all the surfaces scribed carefully, over the original paneling which is close to the real one. All the freshly scribed areas cleared with a used toothbrush followed by Gunze glue (blue). The cockpit was the first part that had been constructed. The details were typical for the scale and some basic modifications needed on the seat and the tub, as shown in the Photos. The belts extracted directly from the Eduard p.e. set. Throttle and other levers created and added on the instrumentation panel. The elevations on the surfaces drybrushed with lighter colors than the basics, as well as chipping made with aluminum color. The engine intake scratchbuilded out of aluminum sheet and at its end a printed replica of the first compressor stage glued. Both cabin floor and intake fitted on the fuselage from the ventral gap. The parts of the canopy created using a hairdryer (both movable and fixed). Their edges cleared using scissors and the exact dimensions achieved comparing them to the original ones. The windscreen glued on the fuselage using a small amount of cyanoacrylate glue. Wing halves glued together, noticing their excellent fitting. Ailerons and flaps separated by their main bodies using a saw in order to be glued extended. On that airplane, when the flaps extended, the ailerons followed, on a smaller angle. The reconnaissance version (S-29) has been chosen to be built, while the other version that the kit offers was an Austrian J-29. Camera bays cut and details made out of plastic sheet, epoxy putty (cameras), copper wire and other materials. Landing gear bays modified also a little bit. At the end, only small amounts of putty used to fill the gaps, because the kit’s fitting proved to be superb. Spoilers on the wings made of aluminum sheet copying the kit’s ones. Landing gears glued on the fuselage, hydraulic lines made of copper wire, painted aluminum and covered with napkins and paper tape. Napkins and Humbrol maskoll used to seal the cockpit, engine exhaust and landing bays.
PAINTING
In order to be checked for possible disorders, the model primered with Testors aluminum. Firstly, the nose painted with yellow and when dried, masked with tape. The first camo color applied, Μr. Hobby Η 42 (blue-grey) followed by the second, Μr. Hobby Η 52 (olive drab). At the end, a ventral part of the wings has been painted with black color and the model left to dry completely. The quality of the decals was really good as well their thickness. Thinned oil colors applied in the paneling and when dried the kit sprayed entirely with 2 thin layers of Μr. Hobby satin varnish (mat to gloss ratio 1:2, respectively). The panel edges rubbed off with a cutting tool, especially close to the cockpit area, in order to reveal the aluminum color. Another process was the lightning of the upper surface panels and the insignias with oil colors. Post shading, applied in the paneling using thinned Tamiya smoke. Oil leaks painted on the engine area and on landing gears using again oil colors. Navigation warning lights cut carefully from the body and replaced with epoxy putty while painted accordingly. The end of the construction came when the movable part of the canopy glued, as well the pitot tube and the antenna which made of aluminum foil.
EPILOGUE
The lilliputian “barrel” was an enjoyable project. Although, being a poor kit, with only few parts and old moulds, ended to be a realistic one. Either you build it out of the box, either with add-ons, you will attain a small ornament in your model collection.
Construction, text, photos: Giannis Asimakos
Translation: Alexandros Ntakis
