Lockheed C-5 Galaxy
In 1963 the USAF's Military Air Transport Service issued a requirement for a very large logistics transport aircraft. Finally, this and other requirements evolved into specification CX-HLS (Cargo. Experimental-Heavy Logistics System) which demanded an aircraft capable of carrying a payload of 56 700 kg (125 000 lb) over a range of 12 875 km (8000 miles) and twice that weight over shorter distances. It also had to be able to take off from the same runways as the smaller C-141 StarLifter and have the capacity to land on roughly-prepared strips in combat areas. In May 1964 the Boeing, Douglas and Lockheed companies were asked to develop their submitted designs further. The gross weight requirement had by then been increased to 317 500 kg (700 000 lb), and General Electric and Pratt & Whitney were invited to design a suitable powerplant. Towards the end of the following year the choice was made in favour of a Lockheed/General Electric partnership, and the aircraft was officially designated C-5A Galaxy.
Eight test and evaluation machines were built, beginning in August 1966, the first C-5A Galaxy (#66-8303) was "rolled out" on 2 March 1968.
On June 30th 1968 Lockheed-Georgia Co. began flight testing with the aircraft’s first flight taking to the air under the call-sign "Allen-zero-three-heavy", upon completion of testing the first C-5A was transferred to the Transitional Training Unit at Altus Air Force Base, OK, in December 1969.
It is a high-wing cantilever monoplane, with a semimonocoque two-deck fuselage of aluminium and titanium alloy construction and a cantilever all-metal 'T' tail. The nosewheel unit retracts rearward hydraulically, as do the four main undercarriage bogies, each consisting of two sets of wheels in tandem on each side of the fuselage. Powered by four General Electric TF39-GE-1 turbofan engines, each rated at 18600 kg (41005 lb) thrust at sea level, the Galaxy carries a maximum usable fuel load of 185 480 litres (40 800 Imp gal) and can be refuelled in flight from a KC-135 tanker via an inlet in a fairing on top of the forward fuselage, just aft of the flight deck. For takeoff, a fully-loaded Galaxy needs 2135 m (7004 ft) of runway, but can land in 680 m (2230 ft).
A crew of five is normally carried, including a loadmaster, and there is a forward rest area on the upper deck for 15 persons (relief crew, etc). Although intended primarily as a freighter, the basic version can carry 75 troops at the rear of the upper deck and 270 on the lower deck. Loads lifted have included a 35380-kg (78000-lb) Minuteman ICBM and its 3175-kg (7000-1b) launching cradle; two 44 905-kg (99 000-1b) M-48 tanks; or three Boeing Vertol Chinook heavy-lift helicopters. Loading can be done from front or rear, or from both ends simultaneously. There is an upward-hinged nose door and loading ramp at the front; the rear straight-in loading ramp, when closed, forms part of the undersurface of the rear fuselage.
Flight testing of the Galaxy continued until the summer of 1971. Deliveries of production aircraft to Military Airlift Command began on December 17, 1971, (to the 437th Airlift Wing, Charleston Air Force Base, SC) and were completed in May 1973. The C-5A became operational in 1970, and from July of that year was flying regular trips to Southeast Asia and Europe; it was utilized extensively during the Vietnam war for rapid transport of heavy equipment. In 1978, a total of 77 still remained in the MAC inventory of the 81 aircraft built. These were in service with the 60th, 436th, 437th, and 443rd Military Airlift Wings, based at Travis Air Force Base, California; Dover, Delaware; Charles-ton, South Carolina; and Altus, Oklahoma.
Throughout the 1970s, the Galaxy remained the world's largest military transport aircraft, being almost as large and heavy as the later-model Boeing 747 Jumbo jets. Lockheed has calculated that, if required by the USAF, it is capable of being optimized for payloads even greater than the present 100227-kg (220964-1b) maximum, without increasing the maximum takeoff weight.
These aircraft have been put to invaluable use on non-military mercy missions to disaster-stricken areas such as the floods in Chile in 1974 and those in Pakistan. Much-needed equipment and supplies were taken to earthquake-ravaged Nicaragua by Galaxy aircraft, and in early 1977 and 1978 they were used to ferry snow-clearing equipment to several areas within the United States.
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.
Some C-5s were transferred to the Air Reserve components starting with Kelly AFB, Texas, in 1985; followed by Stewart Air National Guard Base, NY; and Westover Air Reserve Base, MA.
In December 1985 Lockheed was awarded a contract to design a new wing for the Galaxy, increasing maximum take-off weight from 348,810kg to 379,660kg. By the end of 1986, 68 rewinged C-5As had been returned to service, and the 77-strong fleet was scheduled for completion by mid-1987.
C-5Bs have the same wing, improved General Electric TF39 turbofans, updated avionics, and better fatigue and corrosion resistance.
Two C-5As modified to carry outsized space cargoes as C-5Cs.
Engines: 4 x GE TF-39-GE-1, 182.9kN / 41,000 lb
Wing span: 222 ft 8.5 in (67.88 m)
Wing area: 576.0 sq.m / 6200.01 sq ft
Length: 247 ft 10 in (75.54 m)
Height: 65 ft 1.5 in (19.85 m)
Max TO wt: 764,500 lb (346,770 kg)
Payload: 73pax, max 130950kg
Max level speed: 571 mph (919 kph)
Cruise speed: 871 km/h / 541 mph
Service ceiling: 33802 ft / 10303 m
Range w/max.fuel: 13472 km / 8371 miles
Range w/max.payload: 5600 km / 3480 miles
Take off distance : 12129 ft / 3697 m
Landing distance : 4872 ft / 1485 m
Engine: 4 x GE TF39 turbofan
Installed thrust: 765 kN
Wingspan: 67.9 m / 222 ft 9 in
Height: 19.8 m / 65 ft 0 in
Length: 75.5 m
Wing area: 576.0 sq.m / 6200.01 sq ft
Empty wt: 169,645 kg
MTOW: 379,660 kg
MLW: 288,630 kg
Payload: 118,390 kg
Max. speed: 920 km/h / 572 mph
Cruise speed: 835 kph
Initial ROC: 440 m / min
Ceiling: 10,895 m
T/O run: 2125 m
Ldg run: 720 m
Fuel internal: 193,640 lt
Range with 118,390 kg payload: 5470 km
Capacity: 75 pax
Air refuel: Yes.