21 April 1964 – Almost 10 years after the first flight of the Lockheed YC-130 Hercules prototype, the commercial military version made it’s longest flight. The aircraft took off from Marietta, GA and flew 25 hours, 1 minute.
The specs for the military transport plane were that it would have a capacity of 92 passengers, 72 combat troops or 64 paratroopers in a cargo compartment that was approximately 41 ft (12 m) long, 9 ft (2.7 m) high, and 10 ft (3.0 m) wide. Unlike transports derived from passenger airliners, it was to be designed specifically as a combat transport with loading from a hinged loading ramp at the rear of the fuselage. A key feature was the introduction of the Allison T56 turboprop powerplant, which was developed for the C-130. The turboprop offered greater range at propeller-driven speeds compared to pure turbojets, which were faster but consumed more fuel. They also produced much more power for their weight than piston engines.
Fairchild, North American, Martin, and Northrop declined to participate. The remaining five companies tendered a total of ten designs: Lockheed two, Boeing one, Chase three, Douglas three, and Airlifts Inc. one. The contest was a close affair between the lighter of the two Lockheed (preliminary project designation L-206) proposals and a four-turboprop Douglas design.
In 1963, a Hercules achieved and still holds the record for the largest and heaviest aircraft to land on an aircraft carrier.
In 1964, C-130 crews from the 6315th Operations Group at Naha Air Base, Okinawa commenced forward air control (FAC; “Flare”) missions over the Ho Chi Minh Trail in Laos supporting USAF strike aircraft. In April 1965 the mission was expanded to North Vietnam where C-130 crews led formations of Martin B-57 Canberra bombers on night reconnaissance/strike missions against communist supply routes leading to South Vietnam. In early 1966 Project Blind Bat/Lamplighter was established at Ubon Royal Thai Air Force Base, Thailand. After the move to Ubon, the mission became a four-engine FAC mission with the C-130 crew searching for targets then calling in strike aircraft. Another little-known C-130 mission flown by Naha-based crews was Operation Commando Scarf, which involved the delivery of chemicals onto sections of the Ho Chi Minh Trail in Laos that were designed to produce mud and landslides in hopes of making the truck routes impassable.
Sources: Today in Aviation History by Brian R. Swopes; Wikipedia