The Lockheed C-5 Galaxy is a large military transport aircraft originally designed and built by Lockheed, and now maintained and upgraded by its successor, Lockheed Martin.
It provides the United States Air Force with a heavy intercontinental-range strategic airlift capability, one that can carry outsized and oversized loads, including all air-certifiable cargo.
The Galaxy has many similarities to the smaller Lockheed C-141 Starlifter and the later Boeing C-17 Globemaster III.
The C-5 is among the largest military aircraft in the world.
The C-5 Galaxy’s development was complicated, including significant cost overruns, and Lockheed suffered significant financial difficulties.
Shortly after entering service, cracks in the wings of many aircraft were discovered and the C-5 fleet was restricted in capability until corrective work was completed.
The C-5M Super Galaxy is an upgraded version with new engines and modernized avionics designed to extend its service life to 2040 and beyond.
The USAF has operated the C-5 since 1969.
In that time, the airlifter supported US military operations in all major conflicts including Vietnam, Iraq, Yugoslavia, and Afghanistan, as well as allied support, such as Israel during the Yom Kippur War and operations in the Gulf War.
The Galaxy has also distributed humanitarian aid, provided disaster relief, and supported the US space program.
The C-5 is a large, high-wing cargo aircraft with a distinctive high T-tail fin (vertical) stabilizer, with four TF39 turbofan engines mounted on pylons beneath wings that are swept 25°.
(The C-5M uses newer GE CF6 engines.)
Similar in layout to its smaller predecessor, the C-141 Starlifter, the C-5 has 12 internal wing tanks and is equipped for aerial refuelling.
Above the plane-length cargo deck is an upper deck for flight operations and for seating 80 passengers in rear facing seats (unlike most commercial airplanes) and the embarked loadmaster crew in forward facing seats.
Bay doors at both nose and tail open to enable “drive-through” loading and unloading of cargo.
The cargo hold of the C-5 is one foot (30 cm) longer than the entire length of the first powered flight by the Wright brothers at Kitty Hawk.
Take-off and landing distance requirements for the plane at maximum-load gross weight are 8,300 ft (2,500 m) and 4,900 ft (1,500 m), respectively.
Its high-flotation main landing gear provides 28 wheels to distribute gross weight on paved or earth surfaces.
The rear main landing gear can be made to caster to make a smaller turning radius and rotates 90° after take-off before being retracted.
“Kneeling” landing gear permits lowering the aircraft when parked, thereby presenting the cargo deck at truck-bed height to facilitate loading and unloading operations.
The C-5 features a malfunction detection analysis and recording system to identify errors throughout the aircraft.
The cargo compartment is 121 ft (37 m) long, 13.5 ft (4.1 m) high, and 19 ft (5.8 m) wide, or just over 31,000 cu ft (880 m3).
It can accommodate up to 36 463L master pallets or a mix of palletised cargo and vehicles.
The nose and aft cargo-bay doors open the full width and height of the cargo bay to maximize efficient loading of oversized equipment.
Full-width ramps enable loading double rows of vehicles from either end of the cargo hold.
The C-5 Galaxy is capable of moving nearly every type of military combat equipment, including such bulky items as the Army armoured vehicle launched bridge, at 74 short tons (67 t), from the United States to any location on the globe; and of accommodating up to six Boeing AH-64 Apache helicopters or five Bradley Fighting Vehicles at one time.
Variants
C-5A
The C-5A is the original version of the C-5.
From 1969 to 1973, 81 C-5As were delivered to the Military Airlift Command of the U.S. Air Force.
Due to cracks found in the wings in the mid-1970s, the cargo weight was restricted.
To restore the C-5’s full capability, the wing structure was redesigned.
A program to install new strengthened wings on 77 C-5As was conducted from 1981 to 1987.
The redesigned wing made use of a new aluminium alloy that did not exist during the original production.
As of August 2016, there were 10 A-models in service flown by the Air Force Reserve Command’s 433d Airlift Wing at Lackland AFB / Kelly Field, Texas, and 439th Airlift Wing at Westover ARB, Massachusetts.
The last operational C-5A was retired on 7 September 2017.
C-5B
The C-5B is an improved version of the C-5A.
It incorporated all modifications and improvements made to the C-5A with improved wings, simplified landing gear, upgraded TF-39-GE-1C turbofan engines and updated avionics.
50 examples of the new variant were delivered to the U.S. Air Force from 1986 to 1989.
C-5C
The C-5C is a specially modified variant for transporting large cargo.
Two C-5As (68-0213 and 68-0216) were modified following major accidents to have a larger internal cargo capacity to accommodate large payloads, such as satellites.
The major modifications were the removal of the rear passenger compartment floor, splitting the rear cargo door in the middle, and installing a new movable aft bulkhead further to the rear.
The official C-5 technical manual refers to the version as C-5A(SCM) Space Cargo Modified. Modifications also included adding a second inlet for ground power, which can feed any power-dependent equipment that may form part of the cargo.
The two C-5Cs are operated by U.S. Air Force crews for DOD spacecraft programs and NASA, and are stationed at Travis AFB, California.
C-5 AMP and C-5M Super Galaxy
New C-5 cockpit avionics, installed under the Avionics Modernization Program
Following a study showing that 80% of the C-5 airframe’s service life was remaining, Air Mobility Command (AMC) began an aggressive program to modernize all remaining C-5Bs and C-5Cs and many of the C-5As.
The C-5 Avionics Modernization Program (AMP) began in 1998 and includes upgrading the avionics to comply with Global Air Traffic Management standards, improving communications, fitting new flat-panel displays, improving navigation and safety equipment, and installing a new autopilot system.
The first flight of a C-5 with AMP (85-0004) occurred on 21 December 2002.
The Reliability Enhancement and Re-engining Program (RERP) began in 2006.
It includes fitting new General Electric F138-GE-100 (CF6-80C2) engines, pylons and auxiliary power units, and upgrades to aircraft skin and frame, landing gear, cockpit and pressurization systems.
Each CF6 engine produces 22% more thrust (50,000 lbf or 220 kN), providing a 30% shorter take-off, a 38% higher climb rate to initial altitude, an increased cargo load and a longer range.
Upgraded C-5s are designated C-5M Super Galaxy.
L-500
Lockheed also planned a civilian version of the C-5 Galaxy, the L-500, the company designation also used for the C-5 itself. Both passenger and cargo versions of the L-500 were designed.
The all-passenger version would have been able to carry up to 1,000 travellers, while the all-cargo version was predicted to be able to carry typical C-5 volume for as little as 2 cents per ton-mile (in 1967 dollars).
Although some interest was expressed by carriers, no orders were placed for either L-500 version, due to operational costs caused by low fuel efficiency, a significant concern for a profit-making carrier, even before the oil crisis of the 1970s, keen competition from Boeing’s 747, and high costs incurred by Lockheed in developing the C-5 and later, the L-1011 which led to the governmental rescue of the company.
C-5 Shuttle Carrier
Lockheed proposed a twin body C-5 as a Shuttle Carrier Aircraft to counter the Conroy Virtus, but the design was turned down in favour of the Boeing 747.
Specifications
Crew
7
Capacity
36 master pallets 463L, 281,000 lb (127,459 kg)
Length
247 ft 1 in (75.31 m)
Wingspan
222 ft 9 in (67.89 m)
Height
65 ft 1 in (19.84 m)
Wing area
6,200 sq ft (580 m2)
Airfoil
Root
NACA 0012.41 mod
Tip
NACA 0011 mod
Empty weight
380,000 lb (172,365 kg)
Gross weight
840,000 lb (381,018 kg)
Max take-off weight
920,000 lb (417,305 kg)
Fuel capacity
51,150 US gal (42,590 imp gal; 193,600 l)
Powerplant
4 × General Electric CF6-80C2 turbofan engines,
51,000 lbf (230 kN) thrust each
Performance
Maximum speed
462 kn (532 mph, 856 km/h)
Maximum speed
Mach 0.79
Cruise speed
450 kn (520 mph, 830 km/h) / M0.77
Range
4,800 nmi (5,500 mi, 8,900 km) with a 120,000 lb (54,431 kg) payload
2,300 nmi (4,260 km; 2,647 mi) with maximum cargo capacity
Ferry range: 7,000 nmi (8,100 mi, 13,000 km) with no cargo on board
