Global Airlift: Anything, Anytime, Anywhere
The Lockheed C-5 Galaxy is a heavy logistics military transport aircraft designed to provide world-wide massive strategic airlift. The CONUS-based fleet can provide delivery of palletized, oversized and outsized cargo, as well as passengers or combat-ready troops, anywhere in the world on short notice. The aircraft can takeoff and land in relatively short distances and taxi on substandard surfaces during emergency operations. The C-5 also plays a limited role in the airdrop and special operations arenas.
In 1963, realizing that they needed a jet-powered replacement for the exhausted, turboprop-powered C-133 Cargomaster, the United States Air Force began to study very large logistic transports. After reviewing several airframe designs, they eventually choose one similar to that of the C-141A Starlifter featuring a high-set wing (swept 25 degrees), four underwing jet engines and a T-tail.
This enormous aircraft, first known as the CX-HLS (Cargo Experimental-Heavy Logistics System) transport, was required to carry a payload of 125,000 pounds (56,700kg) over a distance of 8,000 miles (12,875km), or twice that load over a shorter distance. It also had to be able to operate, at maximum weight capacity, from the same runway lengths and semi-prepared runways as the C-141A (8,000 feet (2,438m) takeoff / 4,000 feet (1,219m) landing). Another major requirement, and the most controversial, was the design-life factor for the wing; it must survive for 30,000 flying hours.
The design competition was between Boeing (which entered its initial designs for the Model 747, before it was incorporated as a commercial passenger carrier), Douglas and Lockheed-Georgia. Lockheed won the contract in October 1965 with a design that was an extension of the company's Hercules/Starlifter series. With a gross weight of 764,500 pounds (346,771kg), Lockheed's Model 500, later designated C-5A Galaxy, dwarfed not only other Air Force transports but also every other type of aircraft in existence.
Construction of the prototype began in August 1966. The first C-5A Galaxy (#66-8303) was "rolled out" on 2 March 1968 and prepared for initial flight trials at Lockheed's Marietta plant, located adjacent to Dobbins AFB in Georgia. The maiden flight took place on 30 June 1968 and lasted 94 minutes; Lockheed pilots Leo J. Sullivan and Walter E. Hensleigh were at the controls. (Note: This aircraft was lost following a ground fire on 17 October 1970.)
The first phase of manufacturer's flight trials proceeded without major problems (except for the loss of a main wheel during a routine landing; the media had a field day with this event). In July 1969, full-scale structural ground static tests resulted in a premature wing failure at 84 percent of the scheduled maximum design load. Nevertheless, while corrective measures were devised, flight tests proceeded in Georgia and California, where the 2nd C-5A had been delivered to Edwards AFB on 4 June 1969 to take part in the 6-month joint Air Force/contractor Category I testing.
Commonly described as, "The Box That The C-141 Came In," the C-5A Galaxy was presented to the United States Air Force, for training purposes, in December 1969. The first operational aircraft were delivered to the 437th Military Airlift Wing (MAW), Charleston AFB, SC, in June 1970.
In the mid-1970s, wing cracks were found throughout the fleet. Consequently, all C-5A aircraft were restricted to a maximum of 50,000 pounds (22,680kg) of cargo each. To increase their lifting capability and service life, 77 C-5As underwent a re-winging program from 1981 to 1987. (In the redesigned wing, a new aluminum alloy was used that didn't exist ten years prior.) The final re-winged C-5A was delivered in July 1986.
In 1982, a new production version, the C-5B, was authorized in which all modifications and improvements evolved in the C-5A program were to be incorporated, including upgraded TF-39-GE-1C turbofan engines, extended-life wings, Bendix color weather radar, triple Delco inertial navigation systems (INS), an improved automated flight control system (AFCS) and a new, more advanced Malfunction Detection Analysis and Recording System (MADAR II). The C-5B dispensed with the C-5A's complex crosswind landing gear system.
The first flight of the C-5B (#83-1285) took place on 10 September 1985. Delivery of the 50 new aircraft commenced in January 1986 and ended in April 1989. All C-5Bs are scheduled to remain in the active duty force, shared by comparably sized Air Force Reserve associate units.
In the late-1980s, NASA had two C-5As (#68-0213 & #68-0216) modified to accommodate complete satellite and space station components. In each aircraft, the troop compartment, located in the aft upper deck, was removed and the aft cargo-door complex was modified to increase the dimensions of the cargo compartment's aft loading area. Both aircraft are currently assigned to Travis AFB in Fairfield, California and have been redesignated as C-models. (Some unofficial sources claim this modification also enables the C-5C to be used for covert transportation of classified material between Lockheed's Skunk Works in California and the test center at Groom Lake, Nevada, also known as Area 51. Lockheed and the U.S. government will neither confirm nor deny the authenticity of this speculation.)
Until the introduction of the Russian An-124 "Condor" (1982), the C-5A Galaxy was the largest and heaviest aircraft in the world. With its massive payload capacity, it has the capability to carry fully-equipped, combat-ready troops to any area of the world on short notice and provide the field support necessary to maintain a fighting force. Since 1970, it has opened unprecedented dimensions of strategic airlift in support of national defense and is invaluable to the Air Force mission and world-wide humanitarian relief efforts.
Exterior Setup - Four turbofan jet engines, high-set wing (swept 25 degrees), T-tail, forward and rear cargo loading assemblies, and a visor-type upward-hinged nose.
- Upper-Deck Accommodations - The forward upper deck (flight deck) seats a cockpit crew of six, a relief crew of seven, and eight dignitaries or couriers; it also has two bunk rooms with three beds in each. The rear upper deck (troop compartment) seats 73 passengers and two loadmasters. Both upper deck compartments are fully pressurized, air-conditioned and incorporate galleys for food preparation and lavatories.
Cargo Compartment - Capacity: 36 fully-loaded 463L-type cargo pallets (88" x 108" @ 10,000 pound (4,536kg) capacity); 270 passengers in the air-bus configuration*; six transcontinental buses; two M1-A1 Abrams main battle tanks; seven UH-1 Huey helicopters; one U.S. Army 74-ton mobile scissors bridge. (A combination of pallets and wheeled vehicles can be carried together when required.)
The Galaxy's massive cargo compartment, with its upward-hinged visor in the nose and outward-opening "clamshell" doors in the rear, accommodates drive-through loading/unloading of wheeled or tracked vehicles using full-width ramps at each end. To accommodate faster, easier loading of outsized or unpowered equipment, each ramp contains an internally-housed winch.
For rapid handling of palletized equipment, the forward and rear ramp assemblies can be repositioned to truckbed height, approximately 10 feet (3.0m) above the ground, and the entire cargo floor converted into a rollerized conveyor system. Thirty-six standard 463L cargo pallets can be loaded aboard in about 90 minutes. When palletized cargo is not being carried, the roller conveyors can be turned over to leave a smooth, flat surface to accommodate wheeled or tracked vehicles.
The C-5 Galaxy has a 121 foot long cargo floor (one foot longer than the Wright Brothers first flight at Kitty Hawk, North Carolina) and nearly 35,000 cubic feet of available cargo space five times greater than that of the C-141A Starlifter! The entire cargo compartment is pressurized and air-conditioned.
* The C-5 only carries passengers or troops in the lower-deck cargo compartment during emergency operations or on special missions authorized by Headquarters AMC.
Landing Gear - The enormous C-5 Galaxy has a very unique landing gear system consisting of a single nose strut, four main bogeys and a total of 28 wheels. The complex system offers "high flotation" capability for unpaved surfaces, freewheel castoring to facilitate ground maneuvering, and an offset swiveling capability (20 degrees left or right) for crosswind landings**. The landing gear system also has the capability of raising each set of wheels individually for simplified tire changes or brake maintenance. Size aside, the aircraft can takeoff or land just about anywhere in the world.
To provide maximum logistical flexibility, the C-5's landing gear assembly also has a three-position "kneeling" system, which can be utilized to lower the aircraft's cargo floor to truckbed height. "Kneeling" of the aircraft is especially needed when loading outsized or long wheel-based equipment because it reduces the angle of the forward or aft ramp critical areas.
** Not adapted to the second production B-model aircraft, and has since been removed from all A-models.
- Power Sources - The electrical system has four engine-driven generators, each powerful enough to supply the aircraft with sufficient electricity. Each of the two main landing gear pods carries an auxiliary power unit (APU) and air turbine motor (ATM) to supply electric/pneumatic and hydraulic power, respectively, for engine starts, ground air conditioning and heating, main landing gear kneeling operations, and forward/aft cargo door operations.
Engines - Four General Electric TF39-GE-1C turbofan engines, rated at 41,000 pounds (183kN) of thrust each, mounted on pylons under the wings power the C-5 Galaxy. Each engine pod is nearly 27 feet (8.2m) long, weighs 7,900 pounds (3,583kg) and has an air intake diameter of more than 8.5 feet (2.6m).
During engine development, a Boeing B-52E (#57-0119) was modified for use as an engine testbed. The engine was mounted on the right inboard pylon in place of the two J57s normally installed there. The single TF-39 turbofan had nearly as much thrust as four standard J57 turbojets.
- Fuel Capacity - The C-5 Galaxy has 12 integral wing tanks with a capacity of 51,450 gallons (332,500 pounds) of fuel enough to fill more than six standard railroad tankers!
- Inflight Refueling Capability - The C-5A Galaxy was the first transport aircraft to incorporate inflight refueling capability as an original design feature. The ability to aerial refuel allows the aircraft to stay airborne indefinitely. With aerial refueling, crew endurance is the only limit to the aircraft's range. (Relief crews are carried on long flights to minimize the crew fatigue factor.)
- MADAR - An automatic trouble-shooting system constantly monitors more than 800 test points in the various subsystems of the aircraft. The Malfunction Detection Analysis and Recording System (MADAR) uses a digital computer to identify malfunctions in replaceable units. Failure and trend information is recorded on magnetic tape for analysis.
- Avionics - The C-5 Galaxy has sophisticated communications equipment and a triple inertial navigation system (INS), making it nearly self-sufficient. It can operate without using ground-based navigational aids.
- Countermeasures - Under the Pacer Snow project, two C-5s received installation of ALE-40 flare dispensers and an AAR-47 missile warning system to provide a measure of self-defense.
The C-5 Galaxy is specifically designed to transport all types of military fighting equipment and associated personnel. The entire spectrum of military inventory, anything and everything that the Army ever intended to be airlifted rolling and tracked armored equipment (including main battle tanks), bridge launchers, helicopters, bulk cargo, troops, etc. can be transported swiftly and efficiently aboard the C-5. inflight refueling capability gives the aircraft nearly unlimited range and increases its flexibility for troop and cargo delivery.
In the airdrop arena, the C-5 Galaxy is capable of delivering up to 60,000 pounds (27,216kg) of equipment per drop. Standard airdrop operations include the following types of hardware: Hummers, Bradleys, tanks, road graters and Howitzers. The C-5's aerial-delivery system is compatible with airdrop platforms of 8, 12, 16, 20, 24, 28 and 32 feet in length. Most personnel drops consist of 73 combat-ready troops.
In 1984, a re-winged C-5A flew at a then world record gross weight of 920,836 pounds (417,684kg) after being air refueled. Less than five years later, a C-5B set a new airdrop record of 190,493 (86,406kg) pounds. The drop, consisting of four 42,000 pound (19,051kg) Sheridan tanks and 73 combat-ready troops, occurred over Fort Bragg, North Carolina on 7 June 1989. The C-5 Galaxy also holds the "unofficial" world record for the heaviest drop over a single zone ... two 60,000 pound (27,216kg) platforms.
The most dramatic display of the Galaxy's capability and value was during operations Desert Shield and Desert Storm. Galaxies comprised only 12 percent of the combined airlift fleet, yet they carried 44 percent of all airlift cargo and flew 23 percent of all strategic airlift missions. Ninety percent of Air Force C-5s were used in Desert Shield/Storm, the rest were flying high-priority missions elsewhere around the world.
Overall, the strategic airlift to the Persian Gulf was the largest since World War II. By the cease-fire, Air Force airlifters had moved 482,000 passengers and 513,000 tons of cargo. Viewed in ton miles, the airlift of Operation Desert Shield/Storm was equivalent to repeating the Berlin Airlift, a 56-week operation, every six weeks.
The Future: Modernization
The U.S. Air Force took delivery of the first C-5A in 1969. The fleet was later retrofitted with a new wing in the mid-1980s. With a projected structural service life of over 50,000 hours, structurally, the C-5 could last well into the 21st century, depending on the model and other factors. However, system obsolescence, reliability and maintainability, operating costs, impacts of corrosion, and required repairs all factor in the service life of an aircraft. Currently, the C-5 has the highest operating cost of any Air Force weapon system.
While the C-5 Galaxy has been the backbone of America's strategic airlift fleet since the early-1970s, reliability rates are dropping because the engines and avionics are showing their age. However, testing and analysis reveal that the C-5 has 80 percent of its structural service life remaining. With modernization, "C-5 operators can realize a 34 percent less cost-per-flying-hour and 44 percent less cost-per-ton-mile of cargo all at 20 percent of the cost of comparable new aircraft."
Lockheed Martin has submitted a proposal to the C-5 Galaxy Modernization Program to replace existing avionics with a modern, highly-reliable digitalized system on all 126 C-5s in the U.S. Air Force fleet. Partnered with LMAS, Honeywell Defense Avionics Systems is providing a Versatile Integrated Avionics package, an FAA-certified system developed by its commercial sister divisions that is the latest implementation of Honeywell's integrated modular avionics technology.
Modernization of the Galaxy's propulsion system would be a follow-on program to the avionics modernization. While the U.S. government has not authorized funds for a new C-5 powerplant until 2003, the program could be moved up after an Analysis of Alternatives has been completed.
Lockheed Martin is teaming with GE Aircraft Engines to offer a new propulsion system anchored by the popular General Electric CF6-80C2 engine. Backed by more than 40 million hours in service, the CF6-80C2 engine can assure operators "like new" aircraft reliability and dramatically improved performance.
With the CF6 engines, the C-5's initial cruise ceiling will increase from 24,000 feet to 33,000 feet. Also, the new engines will provide the Galaxy with 22 percent greater takeoff thrust, 30 percent less takeoff roll, and 58 percent less time-to-climb than with the C-5's current TF39 engines while operating at a 17 percent derate.
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