Sk 37 Viggen

The Saab 37 Viggen, designated Sk 37 in its Swedish Air Force service, was a groundbreaking supersonic strike and fighter aircraft developed by the Saab Group in the 1960s and entered operational service in 1971. Conceived during the Cold War to protect Sweden’s neutral airspace, the Viggen combined a versatile delta‑wing planform with canard foreplanes, giving it excellent low‑level aerodynamics and short‑runway capability. Powered by a single Pratt & Whitney JT8D-derived RM8 turbo‑fan engine, it could thrust‑vector its air‑intake and exploit afterburner to reach Mach 2.0 at altitude while maintaining precise terrain‑following flight at low altitude. The aircraft existed in several variants: the AJ 37 attack version, the J 37 fighter, and the SK 37 reconnaissance and electronic‑warfare model, each sharing a common airframe but equipped with mission‑specific avionics and weapons. Its integrated digital fire‑control system, head‑up display and radar‑guided missiles made it one of the first truly multirole combat jets. The Viggen’s service life, lasting until 2005, demonstrated Sweden’s ability to design, produce and sustain a sophisticated indigenous fighter, influencing later projects such as the JAS 39 Gripen and leaving a lasting imprint on modern aviation design philosophy.

Saab Group

Classification

Production & History

Design & Classification