IGJAS 39 GRIPEN, a short description 1993 July 15 Urban Fredriksson urf@icl.se Gripen means The Griffon or Gryphon. The reason this is not a "Saab" aircraft is that on previous aircraft, Ericsson (radar) and Volvo (engine) used to be subcontractors to Saab, but this time the three companies has formed a common company, Industrial Group JAS. One of the suggestions for the next generation of combat aircraft to replace Viggen, was a new light attack/trainer, combined with modifying the fighter Viggen into an advanced strike version. Instead it was in 1982 decided to build a small, true multi-role aircraft, made possible by advances in several fields. It was found that total cost relative to purchases from abroad would be lower, provided at least 240 units were bought by the air force. As of today, only 140 are on order, which is enough to replace the last Drakens and the strike and recce Viggens. A third production order, to replace our fighter Viggens is expected later on. Several layouts was studied: conventional tail vs canards; dorsal, chin or side air intakes; delta, swept, cranked delta or forward swept wing and so on. In the end an unstable canard layout was adopted, in spite of some critizism that it was risky. Opponents said that it didn't give any better turning performance, and in case of control system failure, the airframe would break up before the pilot could be ejected. Saab had a solution to the latter problem, but kept it secret a long time: In case of failure of the digital fly-by-wire system, the canard is disconnected immediately, and with it free-floating, the aircraft becomes stable. The control system has led to problems. Initially test flights were performed with the leading edge flaps locked in position, as the control laws are simpler then. Problems with it also led to a crash during a landing with gusty sidewinds. In case the digital FBW system fails, there is an analogue channel which is good enough to return to base with. Regarding the ability to point the nose beside the direction of travel, so far it hasn't been done during test flights. If the engine fails, power for the aircraft's systems is provided by a Microturbo APU, which by now is the only major remaining problem, as it has a TBO of about 25% what was specified. There are also backup batteries, but they last only for a short time, so even if you can glide to an airfield, they might not last. The specification for this aircraft says that must be able to operate from 800 m runways, and since early in the program, all flights have been performed from a 9 m x 800 m outline painted on the runway at Saab in Linkoping. It's been possible to allow slightly longer take off and landing runs than Viggen, as all wartime bases are to have several short runways. Stopping distance is reduced by extending the relatively large airbrakes; using the control surfaces to push the aircraft down enabling the brakes to be used harder; tilting the canards forwards 80 deg, making them into large airbrakes and also pushing the nose gear - which also has brakes - down. First prototype flew 9:th Dec 1988. Designations J, Jakt = Fighter A, Attack = Strike S, Spaning = Reconnaissance designation number delivered in service serial numbers ----- JAS 39A 126 1993-04 - 39101- IOC will be in 1995, when they'll start to replace attack Viggens, who are getting old. They'll continue to replace Viggens until 2004, when the last recce Viggen will be retired. From 1997 they'll replace the remaining Drakens. Our fighter Viggens will have to be replaced between 2002 and 2010, for which a further batch of 140 will be needed. ----- JAS 39B 14 1998-04 - - To begin with, the two-seat variant wasn't considered necessary, as simulators are very good today. Market research indicated it would be impossible to export the aircraft without a two-seat version, however. In Swedish use, it will not be much used for conversion training, as Gripen is considered easy to fly, but mostly for tactical training. It will be fully combat capable, apart from having no gun and less fuel. There may even be a genuine tactical use for a two-seat aircraft. ----- | These are the loads that have been trialled __ n __ and shown so far. -----=[(.)]=----- Built in under the left side of the nose is a 27 mm Mauser BK T 1100 litre "flattened" tank, same as on Danish Drakens T T 530 litre tanks, same as on Swedish Drakens 74 74 Rb 74 (AIM-9L) Sidewinders Chaff dispensers are incorporated into the wingtip launchers 75 75 75 75 Rb 75 (AGM-65) Maverick (210 kg) 15 15 Rb 15F jet powered anti-ship missile (598 kg) R R R R 6 x 135 mm M70 rockets (364 kg) BK BK Bombkapsel m/90, Mjolner. Gliding bomblet dispenser. ? The first one delivered to the air force has a pylon mounted under the right intake. The left side seems to be take up by the gun. Also other Sidewinders, Asraam, Amraam, MICA and S225X has been shown together with the aircraft, but as its air defence role comes later than its strike role. What radar AAM will be chosen isn't clear yet. There will also be a reconnaissance pod, but that need is not urgent, as the recce Viggens are expected to last until 2004. Length: 14.15 m, Span: 8.4 m, Height: 4.5 m (I don't know if this is official information or just estimated. could well be the latter, as practically everything about it still is secret.) Engine: Volvo Flygmotor RM 12 (=GE F404/F1J1), 8170 kp JAS 39B Same as above, except for: Length 14.8 m [Various issues of FlygvapenNytt and Allt om Hobby]