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
In 1963, realizing that they needed a jet-powered
replacement for the exhausted, turboprop-powered
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
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
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
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
- 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
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
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
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
* The C-5 only carries passengers or troops in
the lower-deck cargo compartment during emergency
operations or on special missions authorized by
- 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
** 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
- 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
(#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
- 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
- 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
- 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
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
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)
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
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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