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Aviation History
1960
1960 - 3101.PDF
FLIGHT, 30 December 1960 1017 A pair of J 35A intercepters from wing F13 of the Royal Swedish Air Force race like arrow-heads across the azure sky SAAB stands for Svenska Aeroplan Aktiebolaget, or SwedishAeroplane Company. Saab are unique in several respects,and it is appropriate at this time to cast an eye over their operations. In doing so it is well not to forget that Sweden isstrictly neutral, being neither Communist nor a signatory to the North Atlantic Treaty. Perhaps for this very reason the Swedeshave been singularly steadfast in their policy-making; and Saab have yet to suffer cancellation of any major programme. To some extent, of course, this is because they have taken carenot to bite off more than they can chew. Their primary function has always been to design and build military aircraft for the defenceof Sweden. Although the Royal Swedish Air Board has frequently put aircraft of foreign design into squadron service—the lastmajor example being the Hunter—it has always striven to be as self-sufficient as possible, and the burden of responsibility onSaab has not been light. To meet the challenge the company have produced a succession of three single-jet combat aircraft whichstand up well in comparison with any contemporary design. These are the Saab-29, first flown on September 1, 1948; the Saab-32,first flown on November 3, 1952; and the Saab-35, first flown on October 25, 1955. The remainder of this article is concernedchiefly with the two last-mentioned, which are respectively known as the Lansen and Draken. But first it is worth commenting onthe firm as a whole. Saab's headquarters are at Linkoping, just over 100 miles southof Stockholm. Employment here is approximately 4,900, out of a total payroll for all plants and subsidiaries of about 8,400. InNovember 1959 a new factory was opened at Trollhatten increasing the company's output of cars to about 40,000 a year; and it isworth noting that a Saab 96 won the recent RAC Rally, even though it had a smaller engine than any other competitor. Saabare at work in the data-processing field, and also make autopilots and fire-control systems for guided weapons, although detailsremain classified. Other aviation work includes the production of the Alouette 2 under licence from Sud; the Helicopter Divisionat Norrkoping are delivering these machines to the three Swedish armed services, and are about to switch to the Alouette 3. Pro-duction of the Saab-91 Safir continues; well over 300 have been sold to several air forces and civil schools, and last month the firstnine of an order for 15 were flown out to Tunisia. Saab have abandoned the 94 twin-engined version of the Safir and theSaab-105 medium transport. LANSEN AND DRAKEN Saab-32 Lansen In the autumn of 1946 Saab began to studydesigns suitable for replacing the Saab-18B as the standard RSAF attack aircraft. After two years of studying a twin-Ghost projectthe company turned to a design with a single more powerful turbojet, and on December 20, 1948, a Phase-1 (design andmock-up) contract was placed for a tandem-seat aircraft primarily intended for attacking land and sea targets under all weatherconditions or at night. More than 2,000,000 man-hours were required to complete the engineering development, hundreds ofresearch and rig programmes being involved. Originally the Saab-32 was intended to be powered by theindigenous STAL Dovern turbojet, but the Swedes eventually decided not to proceed with the development of their own enginesand Svenska Flygmotor commenced licence-production of the Rolls-Royce Avon 100, designated RM.5, with Svenska after-burner. Although a scaled version of the Saab-32 wing was flown on a Safir, the large slats of the first prototype are replaced in theproduction aircraft by fences. Ailerons and elevators are operated by hydraulic boosters, and the tailplane has variable incidence.All Saab-32 versions have search and navigation radar, and a pressurized and refrigerated cockpit. First deliveries of the Saab-32A were made in December 1955.As the A 32A this aircraft equips all 12 attack squadrons of the RSAF, carrying four 20mm guns and either a pair of Robot 304attack missiles or a wide variety of tanks, bombs or rockets. Delivery of the "several hundred" aircraft involved was com-pleted by mid-1958, and production switched to the two succeed- ing versions. Largely redesigned in detail, the J 32B is anall-weather and night fighter, which first flew on January 7, 1957. Level speed and rate of climb are enhanced by the fitting of anRM.6B, a Swedish variant of the Avon 200, with an enlarged afterburner. A new navigation and radar fire-control system isfitted, together with four 30mm guns. External racks are provided for the same loads as those carried by the attack version, althoughthe most usual stores are Rb 324 Sidewinder air-to-air missiles. Six squadrons are equipped with the J 32B. The third variantis the S 32C, which first flew on March 26, 1957. This reconnais- sance version, which equips five squadrons, can fulfil a wide varietyof reconnaissance missions by day or night. The last Lansen, a J 32B, was delivered in May of this year. SAAB Sweden's Advanced Combat Aircraft Saab-35 Draken In 1949 the RSAF outlined a requirementfor an intercepter capable of destroying "bombers in the transonic speed range." Initially the requirement called for a Mach rangeof 1.4 to 1.5, but in 1956 the sights were raised to Ml.7-1.8. Saab were asked to produce an aeroplane flown by a single pilotyet capable of operating under all kinds of weather or at night from relatively small airfields while carrying all the equipmentneeded to destroy modern jet bombers. Preliminary studies suggested that most of the critical problems posed by the require-ment could be solved by adopting a delta configuration. But in order to obtain an aerodynamically correct e.g. location, theforward fuselage had to be extended and the aircraft became unnecessarily heavy. The optimum solution was found in the"double delta." Such a wing was then unknown, and the Draken design staff—led by Mr Erik Bratt, and eventually numberingmore than 500 technicians—decided to build a small jet aeroplane with which the behaviour of the new wing could be explored. In describing the Draken it is difficult to decide what constitutesfuselage and what can more properly be regarded as part of the wing. Essentially the fuselage has a circular section, and theinboard portion of the wing is the large-chord surface extending aft of the engine intakes, with a leading-edge sweep angle of noless than 80°. It was found possible to dispense with a tailplane, and the overall design is one of extraordinary cleanliness.The fuselage consists of front and rear portions joined by bolts. The forward section, integral with the intake ducts and relatedwing structure, accommodates the radar fire-control, cockpit, nose undercarriage, integral tanks and various systems. The rear por-tion, manufactured as a unit with the rest of the inner wing, contains the engine and afterburner, bag tanks, armament, mainlanding gears and remaining systems. Bolted joints are used to attach the outer wings, each of which has skins machined fromthick sheet. The control surfaces consist of a rudder and inboard and outboard elevons, the outer sections having mass-balanceweights. Each surface is operated by a tandem hydraulic jack, the two chambers of which are connected into separate hydrauliccircuits. There is no feedback, stick forces being generated by a Mach/q-feel system. A three-axis autopilot is fitted. To saveweight, the hydraulic systems operate at a line pressure of 2,9871b/ sq in—which, although comparable with Western practice, andappreciably below the 4,0001b/sq in of the Britannia, is more than double the pressure used in the Saab-29.Following the flight of the first prototype in October 1955, an unusually intensive flight-test programme was required to explorethe exceptional speed range and complicated systems; and, in spite of the utmost miniaturization, the airborne instrumentation inthe first prototype weighed approximately 1,1001b. Gradually the first operational version, designated J 35A, became a reality;quantity production of this version was ordered in 1956 and the
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