| C-5 Galaxy | |
|---|---|
 AUnited States Air Force C-5 in flight | |
| General information | |
| Type | Strategic airlifter |
| National origin | United States |
| Manufacturer | Lockheed Corporation Lockheed Martin |
| Status | In service |
| Primary user | United States Air Force |
| Number built | 131
|
| History | |
| Manufactured | C-5A: 1968–1973 C-5B: 1985–1989 |
| Introduction date | June 1970; 55 years ago (1970-06) |
| First flight | 30 June 1968; 57 years ago (1968-06-30)[1] |
TheLockheed C-5 Galaxy is a largemilitary transport aircraft designed and built byLockheed, and now maintained and upgraded by its successor,Lockheed Martin. It provides theUnited States Air Force (USAF) with a heavy intercontinental-rangestrategic airlift capability, one that can carryoutsized and oversized loads, including all air-certifiable cargo. The Galaxy has many similarities to the smallerLockheed C-141 Starlifter and the laterBoeing C-17 Globemaster III. The C-5 is among thelargestmilitary aircraft in the world. All 52 in-service aircraft have been upgraded to theC-5M Super Galaxy with new engines and modernized avionics designed to extend its service life to 2040 and beyond.
The C-5 Galaxy's development was complicated, including significantcost 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 initially restricted in capability until corrective work was completed.
The USAF has operated the C-5 since 1969. In that time, the airlifter supported US military operations in all major conflicts includingVietnam,Iraq,Yugoslavia, andAfghanistan, as well as allied support, such as Israel during theYom Kippur War and operations in theGulf War. The Galaxy has also distributed humanitarian aid, provided disaster relief, and supported the US space program.
In 1961, several aircraft companies began studying heavy jet transport designs that would replace theDouglas C-133 Cargomaster and complementLockheed C-141 Starlifters. In addition to higher overall performance, theUnited States Army wanted a transport aircraft with a larger cargo bay than the C-141, whose interior was too small to carry a variety of theiroutsized equipment. This need led to the CX-4 requirement of July 1962, for which Lockheed, Boeing, Convair, and Douglas proposed six-engined designs. When the US Army judged the CX-4 specification inadequate for its requirements, by late 1963 the CX-4 specification gave way to the CX-HLC requirement specified an airlifter with four engines, an equipped gross weight of 550,000 pounds (249,000 kg), a maximum payload of 180,000 lb (81,600 kg), and a speed of Mach 0.75 (500 mph or 805 km/h). The cargo compartment was 17.2 ft (5.24 m) wide by 13.5 feet (4.11 m) high and 100 ft (30.5 m) long with front and rear access doors. USAF studies showed that high-bypassturbofan engines were needed for thrust andfuel efficiency requirements.[2]
We started to build the C-5 and wanted to build the biggest thing we could … Quite frankly, the C-5 program was a great contribution to commercial aviation. We'll never get credit for it, but we incentivized that industry by developing [the TF39] engine.
The criteria were finalized and an officialrequest for proposal was issued in April 1964 for the "Heavy Logistics System" (CX-HLS) (previously CX-HLC, "Heavy Logistics Capability"). In May 1964, proposals for aircraft were received fromBoeing,Douglas,General Dynamics,Lockheed, andMartin Marietta.General Electric,Curtiss-Wright, andPratt & Whitney submitted proposals for the engines. After a downselect, Boeing, Douglas, and Lockheed were given one-year study contracts for the airframe, along with General Electric and Pratt & Whitney for the engines.[4] All three of the designs shared a number of features. The cockpit was placed well above the cargo area to allow for cargo loading through a nose door. The Boeing and Douglas designs used a pod on the top of the fuselage containing the cockpit, while the Lockheed design extended the cockpit profile down the length of the fuselage, giving it an egg-shaped cross section. All of the designs hadswept wings, as well as front and rear cargo doors, allowing simultaneous loading and unloading.[5] Lockheed's design featured aT-tail, while the designs by Boeing and Douglas had conventional tails.[6][7][8]
The Air Force considered Boeing's design to be better than that of Lockheed, but Lockheed's proposal was the lowest total-cost bid.[9] Lockheed was selected as the winner in September 1965, then awarded a contract in December 1965.[6][10] General Electric'sTF39 engine was selected in August 1965 to power the new transport plane.[6] At the time, GE's engine concept was revolutionary, as all engines before had abypass ratio less than two-to-one, while the TF39 promised and would achieve a ratio of eight-to-one, which had the benefits of increased engine thrust and lower fuel consumption.[11][12] Boeing lost the military contract, but went on to develop its proposal into the successful civilianBoeing 747, the world's firstwide-body airliner, with 1,574 aircraft built when manufacturing ended in 2022 after 54 years of production.
The first C-5A Galaxy (serial number66-8303) was rolled out of the manufacturing plant inMarietta, Georgia, on 2 March 1968.[13] On 30 June 1968, flight testing of the C-5A began with the first flight, flown by Leo Sullivan, with thecall sign "eight-three-oh-threeheavy". Flight tests revealed that the aircraft exhibited a higherdrag divergence Mach number than predicted by wind tunnel data. The maximum lift coefficient measured in flight with the flaps deflected 40° was higher than predicted (2.60 vs. 2.38), but was lower than predicted with the flaps deflected 25° (2.31 vs. 2.38) and with the flaps retracted (1.45 vs. 1.52).[14]
After being one of the worst-run programs, ever, in its early years, it has evolved very slowly and with great difficulty into a nearly adequate strategic airlifter that unfortunately needs in-flight refueling or a ground stop for even the most routine long-distance flights. We spent a lot of money to make it capable of operating from unfinished airstrips near the front lines, when we never needed that capability or had any intention to use it.
Aircraft weight was closely controlled during design and development. At the time of the first flight, the weight was below the guaranteed weight, but by the time of the delivery of the 9th aircraft, had exceeded guarantees.[14] In July 1969, during a fuselage upbending test, the wing failed at 128% of limit load, which is below the requirement that it sustain 150% of limit load. Changes were made to the wing, but during a test in July 1970, it failed at 125% of limit load. A passive load-reduction system, involving uprigged ailerons, was incorporated, but the maximum allowable payload was reduced from 220,000 to 190,000 lb (100,000 to 86,000 kg). At the time it was predicted, with a 90% probability, that no more than 10% of the fleet of 79 airframes would reach theirfatigue life of 19,000 hours without cracking of the wing.[14]
Cost overruns and technical problems of the C-5A were the subject of a congressional investigation in 1968 and 1969.[16][17] The C-5 program was the first development program with a $1‑billion (equivalent to $8.6 billion today) overrun.[10][18] Due to the C-5's troubled development, theDepartment of Defense abandonedTotal Package Procurement.[19] In 1969, Henry Durham raised concerns about the C-5 production process with Lockheed, his employer. Subsequently, Durham was transferred and subjected to abuse until he resigned. TheGovernment Accountability Office substantiated some of his charges against Lockheed. Later, theAmerican Ethical Union honored Durham with the Elliott-Black Award.[20] The Deputy Assistant Secretary of the Air Force for Management Systems, Ernest Fitzgerald, was another person whose fostering of public accountability was unwelcome.[21]
Upon completion of testing in December 1969, the first C-5A was transferred to the Transitional Training Unit atAltus Air Force Base, Oklahoma. Lockheed delivered the first operational Galaxy to the437th Airlift Wing,Charleston Air Force Base, South Carolina, in June 1970. Due to higher than expected development costs, in 1970, public calls were made for the government to split the substantial losses that Lockheed was experiencing.[22] Production was nearly brought to a halt in 1971 as Lockheed went through financial difficulties, due in part to the C-5 Galaxy's development, as well as a civilian jet liner, theLockheed L-1011.[23] The U.S. government gave loans to Lockheed to keep the company operational.[24]
In the early 1970s,NASA considered the C-5 for theShuttle Carrier Aircraft role, to transport theSpace Shuttle toKennedy Space Center. However, they rejected it in favor of theBoeing 747, in part due to the 747's low-wing design.[25] In contrast, theSoviet Union chose to transport its shuttles using the high-wingedAn-225,[26] which derived from theAn-124, which is similar in design and function to the C-5.
During static andfatigue testing, cracks were noticed in the wings of several aircraft,[18] and as a consequence, the C-5A fleet was restricted to 80% of maximum design loads. To reduce wing loading, load alleviation systems were added to the aircraft.[27] By 1980, payloads were restricted to as low as 50,000 lb (23,000 kg) for general cargo during peacetime operations. A $1.5 billion program (equivalent to $8.3 billion today), known as H-Mod,[28] to re-wing the 76 completed C-5As to restore full payload capability and service life began in 1976.[29][30] After design and testing of the new wing design, the C-5As received their new wings from 1980 to 1987.[31][32][33]
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On 24 October 1974, theSpace and Missile Systems Organization successfully conducted anair-launched ballistic missile test, where an 86,000-pound (39,000 kg)LGM-30B Minuteman I ICBM[34] got extracted by parachute from a C-5A Galaxy at 20,000 feet (6,100 m) over the Pacific Ocean (see alsoLAPES). The missile descended to 8,000 feet (2,400 m) before its rocket engine fired. The 10-second engine burn carried the missile to 20,000 feet (6,100 m) again before it dropped into the ocean. The test proved the feasibility of launching an intercontinental ballistic missile from the air (seevideo). Operational deployment was discarded due to engineering and security difficulties, though the capability was used as a negotiating point in theStrategic Arms Limitation Talks.[35][36] 39 years later, aircraft 69–0014, "Zero-One-Four" used in the test was retired to theAir Mobility Command Museum atDover Air Force Base,[37] becoming the first C-5 Galaxy retired to a museum.[38]
In 1974,Imperial Iran, having good relations with the United States, offered $160 million (equivalent to $1,020 million today) to restart C-5 production to enable Iran to purchase aircraft for their own air force,[39][40] in a similar climate as to their acquisition ofF-14 Tomcat fighters.[41] However, no C-5s were ordered by Iran, and the prospect was firmly halted by theIranian Revolution in 1979 when the Imperial State of Iran was replaced by theIslamic State of Iran.[42][43]
As part of PresidentRonald Reagan's military policy, funding was made available for expansion of the USAF's airlift capability. With the C-17 program still some years from completion, Congress approved funding for a new version of the C-5, the C-5B, in July 1982, to expand airlift capacity.[44][45][46] The first C-5B was delivered to Altus Air Force Base in January 1986. In April 1989, the last of 50 C-5B aircraft was added to the 77 C-5As in the Air Force's airlift force structure. The C-5B includes all C-5A improvements and numerous additional system modifications to improve reliability and maintainability.[47]
In 1998, the Avionics Modernization Program (AMP) began upgrading the C-5's avionics to include aglass cockpit, navigation equipment, and a new autopilot system.[48] Another part of the C-5 modernization effort is the Reliability Enhancement and Re-engining Program (RERP). The program replaced the engines with newer, more powerful ones.[49]
A total of 52 C-5s were contracted to be modernized, consisting of 49 B-, two C- and one A-model aircraft through the RERP. The program featured over 70 changes and upgrades, including the newer General Electric engines.[50][51] Three C-5s underwent RERP for testing purposes.Low-rate initial production started in August 2009 with Lockheed reaching full production in May 2011;[citation needed] 22 C-5M Super Galaxies have been completed as of August 2014.[52] RERP upgrades were completed on 25 July 2018. The Air Force received the last modified aircraft on 1 August 2018.[53][54]
In 2014, Lockheed investigated drag reduction by plasma-heating of turbulenttransonic airflow in critical points, saving overall weight by reducing fuel consumption. TheAir Force Research Laboratory looked intoshape-memory alloy for speed-dependentvortex generators.[55]
The C-5 is a large, high-wing cargo aircraft with a highT-tail and wings that areswept 25° which mount fourGeneral Electricturbofan engines — initiallyGE TF39s, but later upgraded toGE CF6s. It was similar in layout to the smaller Lockheed military transport, the C-141 Starlifter, which was introduced in 1965. The C-5 has 12 internal wing tanks and is equipped foraerial refueling. Above the cargo deck is an upper deck for thecockpit and seating for 80 passengers in rear-facing seats andLoadmasters in forward-facing seats.
The cargo hold of the C-5 is one foot (30 cm) longer than the entire length of the first powered flight by theWright brothers atKitty Hawk, North Carolina.[56] For its voracious consumption of fuel and its maintenance and reliability issues[57] the Galaxy's aircrews have nicknamed it "FRED", for Fucking[N 1] Ridiculous Economic/Environmental Disaster.[57]
Takeoff and landing distance requirements for the plane at maximum-load weights are 8,300 ft (2,500 m) and 4,900 ft (1,500 m), respectively. Its high-flotationmain landing gear provides 28 wheels to distribute the 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 takeoff before being retracted. "Kneeling" landing gear lowers the aircraft when parked so the cargo deck is at truck-bed height to make it easy to load and unload.[60]
The C-5 has a malfunction detection analysis and recording system to identify maintenance issues.[33]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 36463L master pallets or a mix of palletized 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.[citation needed]
The C-5 Galaxy is capable of moving nearly every type of military combat equipment, including such bulky items as the Armyarmored vehicle launched bridge, at 74 short tons (67 t), from the United States to any location on the globe;[citation needed] and of accommodating up to sixBoeing AH-64 Apache helicopters or fiveBradley Fighting Vehicles at one time.[32]
The first C-5A was delivered to the USAF on 17 December 1969. Wings were built up in the early 1970s atAltus AFB, Oklahoma;Charleston AFB, South Carolina;Dover AFB, Delaware; andTravis AFB, California. The C-5's first mission was on 9 July 1970, in Southeast Asia during theVietnam War.[61] C-5s were used to transport equipment and troops, including Army tanks and even some small aircraft, throughout the later years of the US action in Vietnam.[62] In the final weeks of the war, prior to theFall of Saigon, several C-5s were involved in evacuation efforts. Duringone such mission, a C-5A crashed while transporting a large number of orphans, with over 140 killed.[63][64]
C-5s have also been used to deliver support and reinforce various US allies over the years. During theYom Kippur War in 1973, multiple C-5s and C-141 Starlifters delivered critical supplies of ammunition, replacement weaponry and other forms of aid to Israel, the US effort was named asOperation Nickel Grass.[65][66] The C-5 Galaxy's performance in Israel was such that the Pentagon began to consider further purchases.[67] The C-5 was regularly made available to support American allies, such as the British-led peacekeeper initiative inZimbabwe in 1979.[68]
The C-5 has been used for several unusual functions. During the development of the secretive stealth aircraft, theLockheed F-117 Nighthawk, Galaxies were often used to carry partly disassembled aircraft, leaving no exterior signs as to their cargo.[69] The C-5 remains the largest aircraft to operate in the Antarctic,[70] capable of operating fromWilliams Field nearMcMurdo Station.[71] The C-5 Galaxy was a major supply asset in the international coalition operations in 1990–91 againstIraq in theGulf War.[72][73][74] C-5s have routinely delivered relief aid and humanitarian supplies to areas afflicted with natural disasters or crisis; multiple flights were made overRwanda in 1994.[75] The C-5 is also used to transport the helicopters that often serve asMarine One.[76]
The wings on the C-5As were replaced during the 1980s to restore full design capability.[31] The USAF took delivery of the first C-5B on 28 December 1985 and the final one in April 1989.[77] The reliability of the C-5 fleet has been a continued issue throughout its lifetime,[78][79] however the C-5M upgrade program seeks in part to address this issue.[49] Their strategic airlift capacity has been a key logistical component of U.S. military operations inAfghanistan andIraq. Following an incident duringOperation Iraqi Freedom where one C-5 was damaged by a projectile, the installation of defensive systems has become a stated priority.[80]
Following a study showing that 80% of the C-5 airframe's service life was remaining,[81]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 withGlobal 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.[82]
The Reliability Enhancement and Re-engining Program (RERP) began in 2006. It includes fitting newGeneral ElectricF138-GE-100 (CF6-80C2) engines, pylons and auxiliary power units, and upgrades to aircraft skin and frame, landing gear, cockpit and pressurization systems.[49][83] Each CF6 engine produces 22% more thrust (50,000 lbf or 220 kN),[84] providing a 30% shorter takeoff, a 38% higher climb rate to initial altitude, an increased cargo load and a longer range.[49][85] Upgrades to all fifty C-5Bs and both C-5Cs were completed by August 2018.[54] These aircraft are now designatedC-5M Super Galaxy.[86]
The C-5 AMP and RERP modernization programs plan to raisemission-capable rate to a minimum goal of 75%.[49] Over the next 40 years, the U.S. Air Force estimates the C-5M will save over $20 billion.[87] The first C-5M conversion was completed on 16 May 2006 and C-5Ms began test flights atDobbins Air Reserve Base in June 2006.[87] In 2008, the USAF decided to convert remaining C-5Bs and C-5Cs into C-5Ms with avionics upgrades and re-engining.[88] The C-5As will receive only the avionics upgrades.[88][89] The last of 52 C-5Ms was delivered to Air Mobility Command in August 2018.[90]
In response to Air Force plans to retire older C-5 aircraft, Congress implemented legislation that set limits on retirement plans for C-5As in 2003.[91] As of November 2013, 45 C-5As have been retired, 11 have been scrapped, parts of one (A/C 66-8306) are now a cargo load trainer at Lackland AFB, Texas, and one was sent to theWarner Robins Air Logistics Center (WR-ALC) for tear down and inspection to evaluate structural integrity and estimate the remaining life for the fleet.[92]
The U.S. Air Force began to receive refitted C-5M aircraft in December 2008.[93] Full production of C-5Ms began in the summer of 2009.[94] In 2009, the Congressional ban on the retirement of C-5s was overturned.[95] The Air Force seeks to retire one C-5A for every 10 newC-17s ordered.[96] In October 2011, the445th Airlift Wing based atWright-Patterson Air Force Base replaced all remaining C-5s with C-17s.[97] The C-5M reachedinitial operating capability (IOC) on 24 February 2014 with 16 aircraft delivered.[98]
On 13 September 2009, a C-5M set 41 new records and flight data was submitted to theNational Aeronautic Association for formal recognition. The C-5M had carried a payload of 176,610 lb (80,110 kg) to over 41,100 ft (12,500 m) in 23 minutes, 59 seconds. Additionally, 33 time to climb records at various payload classes were set, and the world record for greatest payload to 6,562 ft (2,000 m) was broken. The aircraft was in the category of 551,200 to 661,400 lb (250,000 to 300,000 kg) with a takeoff weight of 649,680 lb (294,690 kg) including payload, fuel, and other equipment.[99]
On 18 July 2017, C-5s based at Dover were ordered to stand down so maintenance crews could determine the cause for some nose landing gear failing.[100] The last TF39-powered C-5 flew in late 2017.[101][102]
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 newaluminum alloy that did not exist during the original production.[103] As of August 2016, there were ten 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.[104] The last operational C-5A was retired on 7 September 2017.[105]
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. Fifty examples of the new variant were delivered to the U.S. Air Force from 1986 to 1989.[106]
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.[107] 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 andNASA, and are stationed at Travis AFB, California.
Proposed during the 1990s Non-Developmental Airlift Aircraft (NDAA) program as an alternative to further purchases of theMcDonnell Douglas C-17 Globemaster III as well as a replacement for older C-5As. The C-5D was to haveGeneral ElectricF138-GE-100 (CF6-80C2) engines, improved avionics and significantly improved reliability and maintainability, although it could not use austere runways or conductairdrop operations and had a higher expected operating cost. The plan was canceled in favor of the purchase of more C-17s. The specifications of the C-5D were later used in the C-5M upgrade program.[108]
_Lockheed_L-500_model_(unbuilt_civil_version_of_Lockheed_C-5_Galaxy)_from_1968.png)
Lockheed planned a civil version of the C-5 Galaxy, theL-500, also the internal company designation 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 travelers, while the all-cargo version was predicted to be able to carry typical C-5 volume for as little as 2 cents perton-mile (in 1967 dollars).[109] An order for six L-500s and another six options was negotiated byExecutive Jet Aviation (EJA) (today better known as NetJets) contingent on obtaining government permission to buy a small Montana airline,Johnson Flying Service, part of highly ambitious plans that came to nothing in the late 1960s when it was discovered that EJA was backed by thePennsylvania Railroad, it then being illegal for a railroad to own an airline.[110]
Another L-500 proponent wasLamar Muse, then CEO ofUniversal Airlines, a US charter carrier, later the highly-successful founding CEO ofSouthwest Airlines. Muse believed the L-500 could be used to cheaply transport people with their cars. A cutaway model of a passenger/freight hybrid L-500 featured in Universal Airlines 1968 annual report[111] (seeExternal links for a link). Lockheed's CEO flew to Universal's Michigan headquarters to let Muse know personally when Lockheed's board decided it could not go further with the L-500, given its commitment to theLockheed L-1011 widebody jetliner, then in development. Muse noted later that perhaps Lockheed made the wrong decision, given that the L-1011 was ultimately a significant financial failure.[112]
Lockheed proposed a twin body C-5 as aShuttle Carrier Aircraft to counter theConroy Virtus, but the design (along with the normal single-body C-5 that was also considered) was turned down in favor of the low-wingBoeing 747.[113][114]
%2c_USA_-_Air_Force_AN0568811.jpg)
Three C-5 Galaxy aircraft have been lost in crashes along with two class-A losses resulting from ground fire, with a combined total of 169 fatalities. At least two other C-5 crashes have resulted in major airframe damage, but the aircraft were repaired and returned to service.
Data from"Quest for Performance",[134] International Directory of Military Aircraft,[135]and USAF fact sheet[136]
General characteristics
Performance
Aircraft of comparable role, configuration, and era
