Background and requirements The
Korean War showed that
World War II-era
piston-engine transports—
Fairchild C-119 Flying Boxcars,
Douglas C-47 Skytrains and
Curtiss C-46 Commandos—were no longer adequate. 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 long, high, and 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 notable advance for large aircraft was the introduction of a
turboprop powerplant, the
Allison T56 which was developed for the C-130. It gave the aircraft greater range than a
turbojet engine as it used less fuel. Turboprop engines also produced much more power for their weight than piston engines. However, the turboprop configuration chosen for the T56, with the propeller connected to the compressor, had the potential to cause structural failure of the aircraft if an engine failed. Safety devices had to be incorporated to reduce the excessive drag from a windmilling propeller. The
Boeing C-97 Stratofreighter had rear ramps, which made it possible to drive vehicles onto the airplane (also possible with the forward ramp on a
C-124). The ramp on the Hercules was also used to airdrop cargo, which included a
low-altitude parachute-extraction system for
Sheridan tanks and even dropping large improvised "
daisy cutter" bombs. The new Lockheed cargo plane had a range of and it could operate from short and unprepared strips. Fairchild, North American, Martin, and Northrop declined to participate in the competition. The remaining five companies submitted a total of ten design proposals: Lockheed presented two, Boeing one, Chase three, Douglas three, and Airlifts Inc. one. The competition ultimately narrowed to a close contest between the lighter of Lockheed's two submissions—designated the preliminary
L-206 project—and a four-turboprop aircraft design proposed by Douglas. 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." The first flight of the
YC-130 prototype was made on 23 August 1954 from the
Lockheed plant in
Burbank, California. The aircraft,
serial number 53-3397, was the second prototype, but the first of the two to fly. The YC-130 was piloted by Stanley Beltz and Roy Wimmer on its 61-minute flight to
Edwards Air Force Base;
Jack Real and Dick Stanton served as flight engineers. Kelly Johnson flew chase in a
Lockheed P2V Neptune. After the two prototypes were completed, production began in
Marietta, Georgia, where over 2,300 C-130s have been built through 2009. The initial production model, the
C-130A, was powered by
Allison T56-A-9 turboprops with three-blade
propellers and originally equipped with the blunt nose of the prototypes. Deliveries began in December 1956, continuing until the introduction of the
C-130B model in 1959. Some A-models were equipped with
skis and re-designated
C-130D. As the C-130A became operational with
Tactical Air Command (TAC), the C-130's lack of range became apparent and additional fuel capacity was added with wing pylon-mounted tanks outboard of the engines; this added of fuel capacity for a total capacity of .
Naming , with a livery depicting the Mythological hero Hercules in the style of
Ancient Greek vase painting. The C-130 was named "
Hercules" by its manufacturer, Lockheed, after the
Greek mythological hero known for his strength, courage and perseverance. Hercules is also the name of a
constellation, which fits the company's tradition of naming aircraft after celestial constellations, along with the
P-2V Neptune and
P-3 Orion. Among the U.S. Armed Forces personnel, the C-130 is nicknamed in
military slang as the "Herk" or "Herky Bird". Due to its versatile airframe and multiple variants designed for diverse military applications and missions, on which it has served from the 1950s to the present day, its name has also been described as fitting for its achievements in military history, with the
Royal Australian Air Force comparing them to the legendary
feats and labours of Hercules. As an homage to the feats of the aircraft and of its namesake, the
Hellenic Air Force painted one of its C-130 aircraft with a livery depicting Hercules in the style of
Ancient Greek vase painting, with the inscription "Expanding the legendary feats of Hercules".
Improved versions C-130E dispatches its flares during a low-level training mission The C-130B model was developed to complement the A-models that had previously been delivered, and incorporated new features, particularly increased fuel capacity in the form of auxiliary tanks built into the center wing section and an AC electrical system. Four-bladed
Hamilton Standard propellers replaced the Aero Products' three-blade propellers that distinguished the earlier A-models. The C-130B had
ailerons operated by hydraulic pressure that was increased from , as well as uprated engines and four-blade propellers that were standard until the J-model. The B model was originally intended to have "blown controls", a system that blows high-pressure air over the control surfaces to improve their effectiveness during slow flight. It was tested on an NC-130B prototype aircraft with a pair of T-56 turbines providing high-pressure air through a duct system to the control surfaces and flaps during landing. This greatly reduced landing speed to just 63 knots and cut landing distance in half. The system never entered service because it did not improve takeoff performance by the same margin, making the landing performance pointless if the aircraft could not also take off from where it had landed. An electronic reconnaissance variant of the C-130B was designated C-130B-II. A total of 13 aircraft were converted. The C-130B-II was distinguished by its false external wing fuel tanks, which were disguised signals intelligence (SIGINT) receiver antennas. These pods were slightly larger than the standard wing tanks found on other C-130Bs. Most aircraft featured a swept blade antenna on the upper fuselage, as well as extra wire antennas between the vertical fin and upper fuselage not found on other C-130s. Radio call numbers on the tail of these aircraft were regularly changed to confuse observers and disguise their true mission. The extended-range
C-130E model entered service in 1962 after it was developed as an interim long-range transport for the Military Air Transport Service. Essentially a B-model, the new designation was the result of the installation of
Sargent Fletcher external fuel tanks under each wing's midsection and more powerful
Allison T56-A-7A turboprops. The hydraulic boost pressure to the
ailerons was reduced back to as a consequence of the external tanks' weight in the middle of the wingspan. The E model also featured structural improvements,
avionics upgrades, and a higher gross weight. Australia took delivery of 12 C130E Hercules during 1966–67 to supplement the 12 C-130A models already in service with the RAAF. Sweden and Spain fly the TP-84T version of the C-130E fitted for aerial refueling capability. The
KC-130 tankers, originally
C-130F procured for the
US Marine Corps (USMC) in 1958 (under the designation
GV-1) are equipped with a removable
stainless steel fuel tank carried inside the cargo compartment. The two wing-mounted hose and drogue aerial refueling pods each transfer up to to two aircraft simultaneously, allowing for rapid cycle times of multiple-receiver aircraft formations, (a typical tanker formation of four aircraft in less than 30 minutes). The
US Navy's
C-130G has increased structural strength allowing higher gross weight operation.
Further developments C-130K (C.3) The
C-130H model has updated Allison T56-A-15 turboprops, a redesigned outer
wing, updated avionics, and other minor improvements. Later
H models had a new, fatigue-life-improved, center wing that was retrofitted to many earlier H-models. For structural reasons, some models are required to land with reduced amounts of fuel when carrying heavy cargo, reducing usable range. The H model remains in widespread use with the
United States Air Force (USAF) and many foreign air forces. Initial deliveries began in 1964 (to the
RNZAF), remaining in production until 1996. An improved C-130H was introduced in 1974, with Australia purchasing 12 of the type in 1978 to replace the original 12 C-130A models, which had first entered
Royal Australian Air Force (RAAF) service in 1958. The U.S. Coast Guard employs the HC-130H for long-range search and rescue, drug interdiction, illegal migrant patrols, homeland security, and logistics. C-130H models produced from 1992 to 1996 were designated as C-130H3 by the USAF, with the "3" denoting the third variation in design for the H series. Improvements included
ring laser gyros for the
INUs, GPS receivers, a partial
glass cockpit (ADI and HSI instruments), a more capable APN-241 color radar,
night vision device compatible instrument lighting, and an integrated radar and missile warning system. The electrical system upgrade included Generator Control Units (GCU) and Bus Switching units (BSU) to provide stable power to the more sensitive upgraded components. The equivalent model for export to the UK is the
C-130K, known by the
Royal Air Force (RAF) as the
Hercules C.1. The
C-130H-30 (
Hercules C.3 in RAF service) is a stretched version of the original Hercules, achieved by inserting a plug aft of the cockpit and an plug at the rear of the fuselage. A single C-130K was purchased by the
Met Office for use by its Meteorological Research Flight, where it was classified as the
Hercules W.2. This aircraft was heavily modified, with its most prominent feature being the long red and white striped atmospheric probe on the nose and the move of the weather radar into a pod above the forward fuselage. This aircraft, named
Snoopy, was withdrawn in 2001 and was then modified by
Marshall of Cambridge Aerospace as a flight testbed for the
A400M turbine engine, the
TP400. The C-130K is used by the
RAF Falcons for parachute drops. Three C-130Ks (Hercules C Mk.1P) were upgraded and sold to the Austrian Air Force in 2002.
Enhanced models helicopter The
MC-130E Combat Talon was developed for the USAF during the
Vietnam War to support
special operations missions in Southeast Asia, and led to both the
MC-130H Combat Talon II as well as a family of other special missions aircraft. 37 of the earliest models currently operating with the
Air Force Special Operations Command (AFSOC) are scheduled to be replaced by new-production MC-130J versions. The
EC-130 Commando Solo is another special missions variant within AFSOC, albeit operated solely by an AFSOC-gained wing in the
Pennsylvania Air National Guard, and is a psychological operations/information operations (PSYOP/IO) platform equipped as an aerial radio station and television stations able to transmit messaging over commercial frequencies. Other versions of the
EC-130, most notably the
EC-130H Compass Call, are also special variants, but are assigned to the
Air Combat Command (ACC). The
AC-130 gunship was first developed during the
Vietnam War to provide
close air support and other
ground-attack duties. The
HC-130 is a family of long-range search and rescue variants used by the USAF and the U.S. Coast Guard. Equipped for the deep deployment of
Pararescuemen (PJs), survival equipment, and (in the case of USAF versions) aerial refueling of combat rescue helicopters, HC-130s are usually the on-scene command aircraft for combat SAR missions (USAF only) and non-combat SAR (USAF and USCG). Early USAF versions were also equipped with the
Fulton surface-to-air recovery system, designed to pull a person off the ground using a wire strung from a helium balloon. The John Wayne movie
The Green Berets features its use. The Fulton system was later removed when aerial refueling of helicopters proved safer and more versatile. The movie
The Perfect Storm depicts a real-life SAR mission involving aerial refueling of a
New York Air National Guard HH-60G by a New York Air National Guard HC-130P. The
C-130R and
C-130T are U.S. Navy and USMC models, both equipped with underwing external fuel tanks. The USN C-130T is similar but has additional avionics improvements. In both models, aircraft are equipped with Allison T56-A-16 engines. The USMC versions are designated
KC-130R or
KC-130T when equipped with underwing refueling pods and pylons and are fully
night vision system compatible. The
RC-130 is a
reconnaissance version developed during the Cold War. Sometimes called "ferret" aircraft, these planes were initially retrofitted standard C-130s. The
Lockheed L-100 (L-382) is a civilian variant, equivalent to a C-130E model without military equipment. The L-100 also has two stretched versions.
Next generation In the 1970s, Lockheed proposed a C-130 variant with
turbofan engines rather than turboprops, but the U.S. Air Force preferred the takeoff performance of the existing aircraft. In the 1980s, the C-130 was intended to be replaced by the
Advanced Medium STOL Transport project. The project was canceled and the C-130 has remained in production. Building on lessons learned, Lockheed Martin modified a commercial variant of the C-130 into a High Technology Test Bed (HTTB). This test aircraft set numerous short takeoff and landing performance records and significantly expanded the database for future derivatives of the C-130. Modifications made to the HTTB included extended chord ailerons, a long chord rudder, fast-acting double-slotted trailing edge flaps, a high-camber wing leading edge extension, a larger dorsal fin and dorsal fins, the addition of three spoiler panels to each wing upper surface, a long-stroke main and nose landing gear system, and changes to the flight controls and a change from direct mechanical linkages assisted by hydraulic boost, to fully powered controls, in which the mechanical linkages from the flight station controls operated only the hydraulic control valves of the appropriate boost unit. The HTTB first flew on 19 June 1984, with civil registration of N130X. After demonstrating many new technologies, some of which were applied to the C-130J, the HTTB was lost in a fatal accident on 3 February 1993, at
Dobbins Air Reserve Base, in Marietta, Georgia. The crash was attributed to disengagement of the rudder fly-by-wire flight control system, resulting in a total loss of rudder control capability while conducting ground minimum control speed tests (Vmcg). The disengagement was a result of the inadequate design of the rudder's integrated actuator package by its manufacturer; the operator's insufficient system safety review failed to consider the consequences of the inadequate design to all operating regimes. A factor that contributed to the accident was the flight crew's lack of engineering flight test training. In the 1990s, the improved
C-130J Super Hercules was developed by Lockheed (later Lockheed Martin). This model is the newest version and the only model in production. Externally similar to the classic Hercules in general appearance, the J model has new turboprop engines, six-bladed propellers, digital avionics, and other new systems.
Upgrades and changes In 2000, Boeing was awarded a contract to develop an Avionics Modernization Program kit for the C-130. The program was hindered with delays and cost overruns until project restructuring in 2007. In September 2009, it was reported that the planned Avionics Modernization Program (AMP) upgrade to the older C-130s would be dropped to provide more funds for the F-35, CV-22 and airborne tanker replacement programs. However, in June 2010,
Department of Defense approved funding for the initial production of the AMP upgrade kits. Under the terms of this agreement, the USAF has cleared Boeing to begin
low-rate initial production (LRIP) for the C-130 AMP. A total of 198 aircraft are expected to feature the AMP upgrade. The current cost per aircraft is , although Boeing expects that this price will drop to US$7 million for the 69th aircraft. An engine enhancement program saving fuel and providing lower temperatures in the T56 engine has been approved, and the US Air Force expects to save $2 billion (~$ in ) and extend the fleet life. In 2021, the Air Force Research Laboratory demonstrated the
Rapid Dragon system which transforms the C-130 into a lethal strike platform capable of launching 12
JASSM-ER with 500 kg warheads from a standoff distance of . Future anticipated improvements support includes support for
JDAM-ER, mine laying, drone dispersal as well as improved standoff range when JASSM-XR become available in 2024.
Replacement In October 2010, the U.S. Air Force released a capability request for information (CRFI) for the development of a new airlifter to replace the C-130. The new aircraft was to carry a 190% greater payload and assume the mission of mounted vertical maneuver (MVM). The greater payload and mission would enable it to carry medium-weight armored vehicles and unload them at locations without long runways. Various options were under consideration, including new or upgraded fixed-wing designs, rotorcraft,
tiltrotors, or even an
airship. The C-130 fleet of around 450 planes would be replaced by only 250 aircraft. The Air Force had attempted to replace the C-130 in the 1970s through the
Advanced Medium STOL Transport project, which resulted in the
C-17 Globemaster III that instead replaced the
C-141 Starlifter. The
Air Force Research Laboratory funded Lockheed Martin and Boeing demonstrators for the
Speed Agile concept, which had the goal of making a STOL aircraft that could take off and land at speeds as low as on airfields less than long and cruise at Mach 0.8-plus. Boeing's design used upper-surface blowing from embedded engines on the inboard wing and blown flaps for circulation control on the outboard wing. Lockheed's design also used blown flaps outboard, but inboard used patented reversing ejector nozzles. Boeing's design completed over 2,000 hours of wind tunnel tests in late 2009. It was a 5 percent-scale model of a narrow body design with a payload. When the AFRL increased the payload requirement to , they tested a 5 percent-scale model of a widebody design with a take-off gross weight and an "
A400M-size" wide cargo box. It would be powered by four
IAE V2533 turbofans. On 26 March 2013, Boeing was granted a patent for its swept-wing powered lift aircraft. In January 2014,
Air Mobility Command,
Air Force Materiel Command and the Air Force Research Lab were in the early stages of defining requirements for the C-X next generation airlifter program to replace both the C-130 and C-17. The aircraft would be produced from the early 2030s to the 2040s. ==Operational history==