The Lockheed C-5 Galaxy is one of the largest military aircraft in the world. It can carry outsize and oversize cargo intercontinental ranges and can take off or land in relatively short distances.
The C-5, with its tremendous payload capability, provides the Air Mobility Command (AMC) intertheater airlift in support of United States national defense.
The forward section of the C-5 Galaxy lifts open to allow loading of bulky items.
The C-5 is similar in appearance to its smaller sister transport, the C-141 Starlifter, although the C-5 is much larger.
Both aircraft have the distinctive high T-tail, 25-degree wing sweep, and four turbofan engines mounted on pylons beneath the wings.
The Galaxy carries nearly all of the Army's combat equipment, including such bulky items as its 74-ton mobile scissors bridge, from the United States to any theater of combat on the globe.
The C-5 has four TF39 turbofan engines, rated at 43,000 lbf (191 kN) thrust each. They weigh 7,900 pounds (3,580 kg) each and have an air intake diameter of more than 8.5 feet (2.6 m). Each engine pod is nearly 27 feet (8.2 m) long.
The first C-5A Galaxy was "rolled out" on 2 March 1968. Upon completion of testing the first C-5A was transferred to the Transitional Training Unit at Altus Air Force Base, OK, in December 1969.
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 (22,700 kg) 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.
The first C-5B incorporating significant improvements such as strengthened wings and updated avionics was delivered to Altus Air Force Base in January 1986. C-5 production concluded with delivery of the last "B" model aircraft in April 1989.
In March 1989, the last of 50 C-5B aircraft was added to the 76 C-5As in the Air Force's airlift force structure. The C-5B includes all C-5A improvements as well as more than 100 additional system modifications to improve reliability and maintainability. All 50 C-5Bs are scheduled to remain in the active-duty force, shared by comparably sized and collocated Air Force Reserve Associate units.
Based on a recent study showing 80% of the C-5 airframe service life remaining, AMC began an aggressive program to modernize the C-5.
The C-5 Avionics Modernization Program began in 1998 and includes upgrading avionics to Global Air Traffic Management compliance, improving navigation and safety equipment, and installing a new autopilot system.
Another part of the plan is a comprehensive re-engining and reliability improvement program, which includes new General Electric CF6-80 engines, pylons and auxiliary power units, with upgrades to aircraft skin and frame, landing gear, cockpit and the pressurization system.
This C-5M modernization program will restore aircraft reliability and maintainability, maintain structural and system integrity, reduce cost of ownership and increase operational capability well into the 21st century.