|SK 37 / SK 37 E - SAAB SK 37 Viggen (1972-2007)|
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prototype of the trainer variant of the SAAB 37 Viggen - SK
37 - flew for the first time in the summer of 1970. It is now
exhibited at the Swedish Air
Force Museum (Flygvapenmuseum) at Malmen, Linköping. See photo at
top. 17 more aircraft were manufactured by SAAB and delivered to the Air
SK 37 was based on the attack version of the Viggen - AJ 37. The
designation ”AJ” indicates that the aircraft’s secondary rôle is
as an interceptor. To get room for a second cockpit, the front fuselage
fuel tank had to be removed. Because of this, the SK 37 usually flies
with a large drop fuel tank. Also the radar and some other avionics were
omitted. The fin was made larger and the rear cockpit was provided with
engine, Swedish designation RM 8A,
was license-built by Volvo Flygmotor. It was based on a Pratt &
Whitney JT8D turbo-fan, designed initially for civil airliners but
further developed in Sweden for its military super-sonic use. The
afterburner was entirely a Swedish design. The engine had a thrust of
12.000 kp/117,6 kN (including reheat).
the JAS 39 Gripen was introduced in the Air Force, ten SK 37 were
converted into ECM aircraft (Electronic Counter Measures) and got the
designation SK 37E. The ECM
operator uses the rear cockpit. The ECMO has a number of active and
passive countermeasures at his command:
- Jamming pod for training and self-protection. The U95 pod is also
developed for use with JAS 39 Gripen. The control and display system is
unique for SK 37E. Together with the U95 pod, this system is called Axel.
- Radar jammer. The antennas are located in the nose. The SK 37E variant
can be recognized by the yellow marking on the radome, which shows the
”window” which allow signals in the S- and C-band to pass the radome
without being attenuated too much.
- Jamming pod for self-protection, developed for the attack and
reconnaissance variants of the 37 Viggen.
- Chaff- and flare dispenser, designed and further developed for the
attack and reconnaissance variants of the 37 Viggen.
27 -or ”Apparat
27” - Radar warning receiver (RVR).
addition to this, FR 31
(Flygradio 31) has been installed in the -E version to be used by the
ECMO for communication independently from the pilot. A modern GPS
(Global Positioning System) has also been integrated with the earlier
16,0 m. Span: 10,6 m. MTOW: 15.587 kg. Max. speed: Mach 2.
also the chapters Jet Fighters, Attack Aircraft and Reconnaissance
below: SK 37 at Wing F 7 (Såtenäs) July, 1973. Photo by Lars E. Lundin,
Photo below: SK 37 at Wing F 7 (Såtenäs) July, 1973. Photo by Lars E. Lundin, Västervik
For the Model Builder
© Lars Henriksson