The US Air Force kicked up a huge dust storm on a dirt runway while delivering the HIMARS rocket artillery system. The Lockheed C-130 Hercules is a four-engine turboprop military transport aircraft designed and built originally by Lockheed, now Lockheed Martin. Capable of using unprepared runways for takeoffs and landings, the C-130 was originally designed as a troop, medivac, and cargo transport aircraft. The versatile airframe has found uses in a variety of other roles, including as a gunship (AC-130), for airborne assault, search and rescue, scientific research support, weather reconnaissance, aerial refueling, maritime patrol, and aerial firefighting. It is now the main tactical airlifter for many military forces worldwide. Over 40 models and variants of the Hercules serve with more than 60 nations.
The C-130 entered service with U.S. in the 1950s, followed by Australia and others. During its years of service, the Hercules family has participated in numerous military, civilian and humanitarian aid operations. The family has the longest continuous production run of any military aircraft in history. In 2007, the C-130 became the fifth aircraft—after the English Electric Canberra, Boeing B-52 Stratofortress, Tupolev Tu-95, and Boeing KC-135 Stratotanker, all designs with various forms of aviation gas turbine powerplants—to mark 50 years of continuous use with its original primary customer, in this case, the United States Air Force. The C-130 is one of the few military aircraft to remain in continuous production for over 50 years with its original customer, as the updated C-130J Super Hercules.
Design and development
Background and requirements
The Korean War, which began in June 1950, showed that World War II-era piston-engine transports—Fairchild C-119 Flying Boxcars, Douglas C-47 Skytrains and Curtiss C-46 Commandos—were inadequate for modern warfare. Thus, on 2 February 1951, the United States Air Force issued a General Operating Requirement (GOR) for a new transport to Boeing, Douglas, Fairchild, Lockheed, Martin, Chase Aircraft, North American, Northrop, and Airlifts Inc. The new transport would have a capacity of 92 passengers, 72 combat troops or 64 paratroopers in a cargo compartment that was approximately 41 feet (12 m) long, 9 feet (2.7 m) high, and 10 feet (3.0 m) wide. Unlike transports derived from passenger airliners, it was to be designed from the ground-up 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, first developed specifically for the C-130. At the time, the turboprop was a new application of turbine engines that used exhaust gases to turn a propeller, which offered greater range at propeller-driven speeds compared to pure turbojets, which were faster but thirstier. As was the case on helicopters of that era, such as the UH-1 Huey, turboshafts produced much more power for their weight than piston engines. Lockheed would subsequently use the same engines and technology in the Lockheed L-188 Electra. That aircraft failed financially in its civilian configuration but was successfully adapted into the Lockheed P-3 Orion maritime patrol and submarine attack aircraft where the efficiency and endurance of turboprops excelled.
The Hercules resembled a larger four-engine brother to the C-123 Provider with a similar wing and cargo ramp layout that evolved from the Chase XCG-20 Avitruc, which in turn, was first designed and flown as a cargo glider in 1947. The Boeing C-97 Stratofreighter also had a rear ramp, which made it possible to drive vehicles onto the plane (also possible with forward ramp on a C-124). The ramp on the Hercules was also used to airdrop cargo, which included low-altitude extraction for Sheridan tanks and even dropping large improvised “daisy cutter” bombs.
The new Lockheed cargo plane design possessed a range of 1,100 nmi (1,270 mi; 2,040 km), takeoff capability from short and unprepared strips, and the ability to fly with one engine shut down. 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.
The Lockheed design team was led by Willis Hawkins, starting with a 130 page proposal for the Lockheed L-206. Hall Hibbard, Lockheed vice president and chief engineer, saw the proposal and directed it to Kelly Johnson, who did not care for the low-speed, unarmed aircraft, and remarked, “If you sign that letter, you will destroy the Lockheed Company.” Both Hibbard and Johnson signed the proposal and the company won the contract for the now-designated Model 82 on 2 July 1951.