Lockheed KS-3A Viking

The Lockheed KS‑3A Viking was a twin‑engine, low‑wing transport aircraft developed by Lockheed Corporation in the early 1950s to meet the United States Air Force’s need for a versatile medium‑range cargo and personnel carrier. First flown on 12 March 1953, the KS‑3A evolved from the earlier L‑749 Constellation series, adopting a pressurized fuselage, tricycle landing gear and a redesigned wing with leading‑edge slats that improved low‑speed handling. Powered by two Allison T56 turboprop engines delivering 4,600 shaft‑horsepower each, the Viking could cruise at 420 knots while carrying up to 9,500 lb of freight or 30 troops on a 1,800‑nm range.

Key features included a modular interior that could be re‑configured for cargo, medevac, or airborne early‑warning missions, and a sophisticated avionics suite with an early digital flight‑control computer. The aircraft’s robust construction and short‑field performance made it popular with both military and civilian operators, leading to a production run of 112 units before it was superseded by the C‑130 Hercules.

The KS‑3A Viking’s contribution lies in demonstrating the practicality of turboprop‑driven transport in the jet age, influencing subsequent designs and providing a reliable workhorse during the Cold‑War logistical buildup.