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{{Short description|American heavy military transport aircraft}}
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{{Use dmy dates|date=June 2021}}
{{Infobox aircraft
| name = C-5 Galaxy
| image = File:Usaf.c5.galaxy.750pix.jpg
| image_caption = A [[United States Air Force]] C-5 in flight
| alt = Top view of four-engine jet transport in flight above mountain range
| aircraft_type = [[Strategic airlifter]]
| national_origin = United States
| manufacturer = [[Lockheed Corporation]] <br>[[Lockheed Martin Aeronautics|Lockheed Martin]]
| first_flight = 30 June 1968<ref>Bakse 1995, p. 91.</ref>
| introduction = June 1970
| retired = 
| status = In service
| primary_user = [[United States Air Force]]
| more_users = 
| produced = C-5A: 1968–1973 <br/>C-5B: 1985–1989
| number_built = 131 {{unbulleted list|C-5A: 81|C-5B: 50}}<!-- Only new built aircraft here, please. -->
| unit cost = C-5A: [[United States dollar|US$]]224.29&nbsp;million (2016)<ref name="auto">{{cite web|title=C-5 A/B/C Galaxy and Super Galaxy|url=https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104492/c-5m-super-galaxy/|website=U.S. Air Force|publisher=United States Air Force|access-date=11 June 2016}}</ref> <br>C-5B: [[United States dollar|US$]]262.75&nbsp;million (2016)<ref name="auto"/> <br>C-5C: [[United States dollar|US$]]129.17&nbsp;million (2016)<ref name="auto"/> <br>C-5M: [[United States dollar|US$]]100.37&nbsp;million (2016)<ref name="auto"/> (equivalent to ${{Inflation|US-GDP|100.37|2016}} million in {{Inflation-year|US-GDP}}){{Inflation/fn|US-GDP}}
| variants = 
}}

The '''Lockheed C-5 Galaxy''' is a large [[military transport aircraft]] designed and built by [[Lockheed Corporation|Lockheed]], and now maintained and upgraded by its successor, [[Lockheed Martin]]. It provides the [[United States Air Force]] (USAF) with a heavy intercontinental-range [[strategic airlift]] capability, one that can carry [[outsize cargo|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 [[List of large aircraft#Military|largest]] [[military aircraft]] in the world. All 52 in-service aircraft have been upgraded to the '''[[#C-5M|C-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 significant [[cost overrun]]s, 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 including [[Vietnam War|Vietnam]], [[Iraq War|Iraq]], [[Yugoslav Wars|Yugoslavia]], and [[War in Afghanistan (2001–present)|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.

==Development==
===CX-4 and Heavy Logistics System===
[[File:210521-F-F3405-0004.jpg|thumb|One of the first C-5A models is given a final inspection before testing in the Arnold Engineering Development Complex 16-foot transonic wind tunnel at Arnold Air Force Base in the mid-1960s.]]
In 1961, several aircraft companies began studying heavy jet transport designs that would replace the [[Douglas C-133 Cargomaster]] and complement [[Lockheed C-141 Starlifter]]s. In addition to higher overall performance, the [[United 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 their [[outsize cargo|outsized 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 {{convert|550000|lb|kg|sigfig=3}}, a maximum payload of {{convert|180000|lb|kg|sigfig=3|abbr=on}}, and a speed of Mach&nbsp;0.75 ({{convert|500|mph|km/h|sigfig=3|abbr=on|disp=or}}). The cargo compartment was {{convert|17.2|ft|m|sigfig=3|abbr=on}} wide by {{convert|13.5|ft|m|sigfig=3}} high and {{convert|100|ft|m|sigfig=3|abbr=on}} long with front and rear access doors. USAF studies showed that high-bypass [[turbofan]] engines were needed for thrust and [[fuel efficiency]] requirements.<ref>Norton 2003, p. 7.</ref>
{{Quote box |align=right |width=33% |quote=We started to build the C-5 and wanted to build the biggest thing we could&nbsp;… 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.|source= General [[Duane H. Cassidy]], former MAC Commander in Chief<ref>Bakse 1995, p. 39.</ref>}}

The criteria were finalized and an official [[request for proposal]] was issued in April 1964 for the "Heavy Logistics System" (CX-HLS) (previously CX-HLC). In May 1964, proposals for aircraft were received from [[Boeing]], [[Douglas D-906|Douglas]], [[General Dynamics]], [[Lockheed Corporation|Lockheed]], and [[Martin Marietta]]. [[GE Aviation|General Electric]], [[Curtiss-Wright]], and [[Pratt & 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.<ref name="Norton_p8-9">Norton 2003, pp. 8–9.</ref> 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 had [[swept wing]]s, as well as front and rear cargo doors, allowing simultaneous loading and unloading.<ref>{{cite news |title=Boeing CX-HLS proposal, artist concept |work=boeingimages.com}} {{cite web |title=Image 1 |url= http://www.boeingimages.com/Docs/BOE/Media/TR3_WATERMARKED/2/9/1/8/BI231307.jpg |archive-url= https://web.archive.org/web/20161220140410/http://www.boeingimages.com/Docs/BOE/Media/TR3_WATERMARKED/2/9/1/8/BI231307.jpg |archive-date=20 December 2016 |url-status=dead}} {{cite web |title=Image 2 |url= http://www.boeingimages.com/Docs/BOE/Media/TR6_WATERMARKED/a/7/2/f/BI231305.jpg |url-status=dead |archive-url= https://web.archive.org/web/20161220140400/http://www.boeingimages.com/Docs/BOE/Media/TR6_WATERMARKED/a/7/2/f/BI231305.jpg |archive-date=20 December 2016}}</ref> Lockheed's design featured a [[T-tail]], while the designs by Boeing and Douglas had conventional tails.<ref name=Norton_p12-3>Norton 2003, pp. 12–13.</ref><ref>{{cite web |url= http://airwaysnews.com/html/museums/boeing-archives-bellevue-washington-usa/boeing-cx-hls-model-196364/19149 |title=Boeing CX-HLS Model at Boeing Corporate Archives – 1963/64 |website=Airway News |url-status=dead |archive-url= https://web.archive.org/web/20141014202050/http://airwaysnews.com/html/museums/boeing-archives-bellevue-washington-usa/boeing-cx-hls-model-196364/19149 |archive-date=14 October 2014}}</ref><ref>{{cite web |url= http://bemil.chosun.com/nbrd/gallery/view.html?b_bbs_id=10044&num=169918 |title=B747기의 전신 – 미 공군 CX-HLS 초대형수송기 사업 보잉사 설계안 |trans-title=B747 aircraft – US Air Force CX-HLS super large transport business – Boeing company design |language=ko |date=29 August 2012 |access-date=30 May 2019}} {{cite web |url= http://bemil.chosun.com/nbrd/bbs/view.html?b_bbs_id=10050&num=4082 |title=Next page |url-status=dead |archive-url= https://web.archive.org/web/20160912215829/http://bemil.chosun.com/nbrd/bbs/view.html?b_bbs_id=10050&num=4082 |archive-date=12 September 2016}}</ref>

The Air Force considered Boeing's design to be better than that of Lockheed, but Lockheed's proposal was the lowest total-cost bid.<ref name= "Norton_p11">Norton 2003, p. 11.</ref> Lockheed was selected as the winner in September 1965, then awarded a contract in December 1965.<ref name=Norton_p12-3 /><ref name="Irving">Erving 1993, pp. 189–190.</ref> General Electric's [[General Electric TF39|TF39]] engine was selected in August 1965 to power the new transport plane.<ref name= Norton_p12-3 /> At the time, GE's engine concept was revolutionary, as all engines before had a [[bypass 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.<ref>Bakse 1995, pp. 39, 74.</ref><ref>Phillips 2004, p. 127.</ref> Boeing lost the military contract but went on to develop the successful 747 civilian airliner with over 1,500 aircraft built when manufacturing ended in 2022 after 54 years of production.

===Into production===
The first C-5A Galaxy ([[United States military aircraft serials|serial number]] ''66-8303'') was rolled out of the manufacturing plant in [[Marietta, Georgia]], on 2 March 1968.<ref>Veronico and Dunn 2004, p. 62.</ref> On 30 June 1968, flight testing of the C-5A began with the first flight, flown by Leo Sullivan, with the [[call sign]] "eight-three-oh-three [[Wake turbulence#Hazard avoidance|heavy]]". Flight tests revealed that the aircraft exhibited a higher [[drag 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).<ref name=AIAAstdy>Garrard, Wilfred C. "The Lockheed C-5 Case Study in Aircraft Design". ''AIAA Professional Study Series''.</ref>

{{Quote box |align=right |width=25% |quote=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.|source= Robert F. Dorr, aviation historian<ref>Tillman 2007, p. 82.</ref>}}

Aircraft weight was a serious issue 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.<ref name=AIAAstdy /> 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 {{convert|220000|to|190000|lb|kg|abbr=on}}. At the time, a 90% probability was predicted that no more than 10% of the fleet of 79 airframes would reach their [[fatigue (material)|fatigue]] life of 19,000 hours without cracking of the wing.<ref name=AIAAstdy />

[[File:C-5 Galaxy.jpg|thumb|left|The fourth C-5A Galaxy ''66-8306'' in the 1980s ''European One'' color scheme|alt=Four-engined jet transport with dark green and gray paint scheme in-flight above clouds]]

Cost overruns and technical problems of the C-5A were the subject of a congressional investigation in 1968 and 1969.<ref>[https://news.google.com/newspapers?id=KhsqAAAAIBAJ&sjid=ISgEAAAAIBAJ&pg=6360,5240655&dq=c5a+overrun&hl=en "Plane costs suppressed, Colonel says"] {{Webarchive|url=https://web.archive.org/web/20160204143819/https://news.google.com/newspapers?id=KhsqAAAAIBAJ&sjid=ISgEAAAAIBAJ&pg=6360,5240655&dq=c5a+overrun&hl=en |date=4 February 2016}}. ''Milwaukee Journal'', 30 April 1969.</ref><ref>[https://www.nytimes.com/1969/11/18/archives/c5a-foe-says-pentagon-stripped-him-of-duties.html "C-5A Foe says Pentagon stripped him of duties"]. ''The New York Times'', 18 November 1969.</ref> The C-5 program has the dubious distinction of being the first development program with a $1{{nbh}}billion (equivalent to ${{inflation|US|1|1969|r=1|fmt=c}} billion today) overrun.<ref name="Irving"/><ref name="Garw">Garwood, Darrell. [https://news.google.com/newspapers?id=tB8aAAAAIBAJ&sjid=MyQEAAAAIBAJ&pg=4104,1070347&dq=galaxy+wings&hl=en "Newest Air Force planes grounded"]. ''Times-News'', 17 January 1970.</ref> Due to the C-5's troubled development, the [[United States Department of Defense|Department of Defense]] abandoned [[Total Package Procurement]].<ref>Nalty 2003, pp. 192–193.</ref> 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. The [[Government Accountability Office]] substantiated some of his charges against Lockheed. Later, the [[American Ethical Union]] honored Durham with the Elliott-Black Award.<ref>[http://www.people.com/people/archive/article/0,,20064257,00.html "A Whistle-blower on the C-5A Gets a New Life"]. ''People'', 15 July 1974.</ref> The Deputy Assistant Secretary of the Air Force for Management Systems, Ernest Fitzgerald, was another person whose fostering of public accountability was unwelcome.<ref name="Rice1971">{{Harvnb|Rice|1971}}</ref>

Upon completion of testing in December 1969, the first C-5A was transferred to the Transitional Training Unit at [[Altus Air Force Base]], Oklahoma. Lockheed delivered the first operational Galaxy to the [[437th 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.<ref>[https://news.google.co.uk/newspapers?id=ojAVAAAAIBAJ&sjid=TfgDAAAAIBAJ&pg=4628,4038459&dq=c-5+cargo&hl=en "General asks U.S. to share Lockheed loss"]. ''Spokane Daily Chronicle'', 29 June 1970.</ref> 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, the [[Lockheed L-1011]].<ref>[https://web.archive.org/web/20070930044753/http://www.time.com/time/magazine/article/0,9171,944387,00.html "New Life for TriStar"]. ''[[Time (magazine)|Time]]'', 17 May 1971. Retrieved 6 January 2007.</ref> The U.S. government gave loans to Lockheed to keep the company operational.<ref>Aspin, Les. [https://www.nytimes.com/1972/08/29/archives/the-lockheed-loan-revisited.html "The Lockheed Loan revisited"]. ''The New York Times'', 29 August 1972.</ref>

In the early 1970s, [[NASA]] considered the C-5 for the [[Shuttle Carrier Aircraft]] role, to transport the [[Space Shuttle program|Space Shuttle]] to [[Kennedy Space Center]]. However, they rejected it in favor of the [[Boeing 747]], in part due to the 747's low-wing design.<ref>Miles, Marvin. [https://pqasb.pqarchiver.com/latimes/access/603137242.html?dids=603137242:603137242&FMT=ABS&FMTS=ABS:AI&type=historic&date=Jun+19%2C+1974&author=&pub=Los+Angeles+Times&desc=Jumbo+Jet+Will+Ferry+Space+Shuttle+Piggyback+Across+U.S.&pqatl=google "Jumbo Jet will ferry Space Shuttle Piggyback across U.S"] {{Webarchive|url=https://web.archive.org/web/20121103110227/http://pqasb.pqarchiver.com/latimes/access/603137242.html?dids=603137242:603137242&FMT=ABS&FMTS=ABS:AI&type=historic&date=Jun+19,+1974&author=&pub=Los+Angeles+Times&desc=Jumbo+Jet+Will+Ferry+Space+Shuttle+Piggyback+Across+U.S.&pqatl=google |date=3 November 2012}}. ''Los Angeles Times'', 19 June 1974.</ref> In contrast, the [[Soviet Union]] chose to transport its shuttles using the high-winged [[Antonov An-225 Mriya|An-225]],<ref>Goebel, Greg. {{usurped|1=[https://web.archive.org/web/20110629113925/http://vectorsite.net/avantgt.html#m3 "Antonov An-225 Mriya ('Cossack')"]}}. ''The Antonov Giants: An-22, An-124, & An-225''. vectorsite.net, 1 November 2009. Retrieved 18 June 2006.</ref> which derived from the [[Antonov An-124|An-124]], which is similar in design and function to the C-5.

During static and [[fatigue testing]], cracks were noticed in the wings of several aircraft,<ref name="Garw"/> 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.<ref>Norton 2003, pp. 31–36.</ref> By 1980, payloads were restricted to as low as {{convert|50000|lb|kg|abbr=on}} for general cargo during peacetime operations. A $1.5&nbsp;billion program (equivalent to ${{inflation|US|1.5|1976|r=1|fmt=c}} billion today), known as H-Mod,<ref>National Research Council 1997, p. 90.</ref> to re-wing the 76 completed C-5As to restore full payload capability and service life began in 1976.<ref>Finney, John W. [https://www.nytimes.com/1975/12/15/archives/c5a-jet-repairs-to-cost-15-billion-pentagon-puts-outlay-to-fix-wing.html "C-5A jet repairs to cost 1.5 billion; Pentagon outs outlay to fix Wing Defects at 1.3 Billion as 'Overruns' continue"]. ''The New York Times'', 15 December 1975.</ref><ref>Coates, James. [https://pqasb.pqarchiver.com/chicagotribune/access/637578602.html?dids=637578602:637578602&FMT=ABS&FMTS=ABS:AI&type=historic&date=Jan+21%2C+1982&author=&pub=Chicago+Tribune&desc=Disputed+C-5+jet+gets+Pentagon+nod&pqatl=google "Disputed C-5 jet gets Pentagon nod"] {{Webarchive|url=https://web.archive.org/web/20121102121554/http://pqasb.pqarchiver.com/chicagotribune/access/637578602.html?dids=637578602:637578602&FMT=ABS&FMTS=ABS:AI&type=historic&date=Jan+21,+1982&author=&pub=Chicago+Tribune&desc=Disputed+C-5+jet+gets+Pentagon+nod&pqatl=google |date=2 November 2012}}. ''Chicago Tribune'', 21 January 1982.</ref> After design and testing of the new wing design, the C-5As received their new wings from 1980 to 1987.<ref name="Norton_p53">Norton 2003, pp. 53–56.</ref><ref name = 'CBO 46'/><ref name="aviationzone">{{cite web|url=http://www.theaviationzone.com/factsheets/c5.asp|title=Lockheed C-5 Galaxy|first=Mike|last=Neely|date=3 April 2022 |publisher=theaviationzone.com}}</ref>

===Restarted production and development===
In 1974, [[Pahlavi Iran|Imperial Iran]], having good relations with the United States, offered $160&nbsp;million (equivalent to ${{inflation|US|160|1974|r=0|fmt=c}} million today) to restart C-5 production to enable Iran to purchase aircraft for their own air force,<ref>{{Cite news |date=1974-05-08 |title=Iran may fund new production of Lockheed C-5 |url=https://www.newspapers.com/article/the-los-angeles-times-iran-may-fund-new/159648529/ |access-date=2024-11-24 |work=The Los Angeles Times |page=79 |via=[[Newspapers.com]]}}</ref><ref name="nytimes-textron-7-may-1974">{{cite news |last1=Wright |first1=Robert A. |url=https://www.nytimes.com/1974/05/08/archives/lockheed-considers-textron-merger-lockheed-weighs-textron-merger.html |title=Lockheed Considers Textron Merger |access-date=18 August 2024 |work=The New York Times |date=8 May 1974 |pages=61}}</ref> in a similar climate as to their acquisition of [[F-14 Tomcat]] fighters.<ref>{{Cite news |last=Marder |first=Murrey |date=1973-07-26 |title=Oil Pact With U.S. Firm: Iran Signs Agreement |url=https://www.newspapers.com/article/victoria-advocate-oil-pact-with-us-fir/159648277/ |access-date=2024-11-24 |work=Victoria Advocate |page=12 |via=[[Newspapers.com]]}}</ref> However, no C-5s were ordered by Iran, and the prospect was firmly halted by the [[Iranian Revolution]] in 1979 when the Imperial State of Iran was replaced by the [[Islamic State of Iran]].<ref>[https://news.google.co.uk/newspapers?id=U4kgAAAAIBAJ&sjid=4mUFAAAAIBAJ&pg=3119,2344531&dq=f14+iran&hl=en "Vital US military technology has been lost to new Iranian regime."] ''Lewiston Evening Journal'', 16 February 1979. Scan via news.google.co.uk</ref><ref>{{Cite news |date=1979-11-09 |title=U.S. cuts off plane parts to Iran |url=https://www.newspapers.com/article/chicago-tribune-us-cuts-off-plane-part/159648415/ |access-date=2024-11-24 |work=Chicago Tribune |page=1 |via=[[Newspapers.com]]}}</ref>

[[File:C-5 Galaxy - 081217-F-5350S-101.jpg|thumb|A Galaxy undergoing the AMP and RERP upgrades, to become a C-5M]]
As part of President [[Ronald 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.<ref>{{Cite news |last=Rowley |first=Storer |date=1982-07-22 |title=House gives Reagan victories on MX, C-5 |url=https://www.newspapers.com/article/chicago-tribune-house-gives-reagan-victo/159648468/ |access-date=2024-11-24 |work=Chicago Tribune |page=1 |via=[[Newspapers.com]]}}</ref><ref>[https://news.google.co.uk/newspapers?id=YBcsAAAAIBAJ&sjid=6cgEAAAAIBAJ&pg=2279,4888426&dq=c-5+galaxy+development&hl=en "U.S. Air Force wants to double Airlift capacity."] ''Times Daily'', 27 January 1982. Scan via news.google.co.uk</ref><ref>Nalty 2003, p. 367.</ref> 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.<ref>Norton 2003, pp. 56–58.</ref>

In 1998, the Avionics Modernization Program (AMP) began upgrading the C-5's avionics to include a [[glass cockpit]], navigation equipment, and a new autopilot system.<ref name="USAFafaJune2007">{{cite journal |last1=Schanz |first1=Marc V. |url=https://www.airandspaceforces.com/article/0607c5/ |title=Life With the C-5 |journal=Air & Space Forces Magazine |date=1 June 2007 |volume=90 |issue=6 |pages=59–60 |access-date=18 August 2024 |publisher=[[Air & Space Forces Association]] |issn=0730-6784}}</ref> 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.<ref name="afm_200401_stg">{{cite web |last1=Tirpak |first1=John A. |title=Saving the Galaxy|url=https://www.airandspaceforces.com/article/0104galaxy/ |website=Air & Space Forces Magazine |access-date= 18 August 2024 |date=1 January 2004}}</ref>

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.<ref name="lock-mart-2nd-c5a">{{cite web |author1=PR Newswire |title=Lockheed Martin Delivers Second Production C-5M Super Galaxy to U.S. Air Force |url=https://news.lockheedmartin.com/2011-04-12-Lockheed-Martin-Delivers-Second-Production-C-5M-Super-Galaxy-to-U-S-Air-Force |publisher=[[Lockheed Martin]] |access-date=18 August 2024 |archive-url=https://archive.today/20130201085812/http://in.reuters.com/article/2011/04/12/idUS162171+12-Apr-2011+PRN20110412 |archive-date=1 February 2013 |url-status=live}}</ref><ref name="First production C-5M">{{cite web |last1=Trimble |first1=Stephen |url=https://www.flightglobal.com/lockheed-martin-inducts-first-c-5b-for-c-5m-modifications/88552.article |title=Lockheed Martin inducts first C-5B for C-5M modifications |website=Flight Global |publisher=DVV Media International Limited |access-date=18 August 2024 |language=en |date=21 August 2009}}</ref> Three C-5s underwent RERP for testing purposes. [[Low rate initial production|Low-rate initial production]] started in August 2009 with Lockheed reaching full production in May 2011;{{citation needed|date=September 2014}} 22 C-5M Super Galaxies have been completed as of August 2014.<ref>{{cite web |url=http://www.lockheedmartin.com/us/news/press-releases/2014/august/140825ae_double-deuce.html |title=Double Deuce |publisher=Lockheed Martin |date=August 2014 |url-status=dead |access-date=3 September 2014 |archive-date=4 September 2014 |archive-url=https://web.archive.org/web/20140904160146/http://www.lockheedmartin.com/us/news/press-releases/2014/august/140825ae_double-deuce.html }}</ref> RERP upgrades were completed on 25 July 2018. The Air Force received the last modified aircraft on 1 August 2018.<ref>{{cite web |url=https://www.af.mil/News/Article-Display/Article/1595570/galaxy-wraps-upgrades-to-become-c-5m-super-galaxy/ |title=Galaxy wraps upgrades to become C-5M Super Galaxy |author=Jonathan Bell |date=7 August 2018 |website=Official United States Air Force Website |access-date=30 May 2019}}</ref><ref name=":0">{{Cite web |last=Woody |first=Chris |date=2018-11-04 |title=Super Galaxys will now soar for decades, but the service has other transport problems |url=https://www.airforcetimes.com/news/your-air-force/2018/11/04/super-galaxys-will-now-soar-for-decades-but-the-service-has-other-transport-problems/ |access-date=2025-05-13 |website=Air Force Times |language=en}}</ref>

In 2014 Lockheed investigated drag reduction by plasma-heating of turbulent [[transonic]] airflow in critical points, saving overall weight by reducing fuel consumption. The [[Air Force Research Laboratory]] looked into [[shape-memory alloy]] for speed-dependent [[vortex generator]]s.<ref name="aviat-week-AFRL-drag">{{cite journal |last1=Warwick |first1=Graham |last2=Norris |first2=Guy |title=AFRL Seeks Drag-Reduction Technologies For Mobility Aircraft |website=aviationweek.com |date=23 September 2014 |url=https://aviationweek.com/aerospace/afrl-seeks-drag-reduction-technologies-mobility-aircraft |access-date=18 August 2024 |publisher=Aviation Week Network |issn=0005-2175 |url-access=subscription}}</ref>

==Design==
[[File:Lockheed C-5 Galaxy loading 135.jpg|alt=|thumb|Lockheed C-5 Galaxy loading on a wet ramp in [[Augusta Regional Airport|Bush Field]], Georgia]]

The C-5 is a large, high-wing cargo aircraft with a distinctive high [[T-tail]] fin (vertical) stabilizer, with four [[General Electric TF39|TF39]] [[turbofan]] engines mounted on [[Aircraft pylon|pylon]]s beneath wings that are [[swept wing|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 refueling]]. 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.{{cn|date=February 2023}}

The cargo hold of the C-5 is {{convert|1|ft|cm|spell=in}} longer than the entire length of the first powered flight by the [[Wright brothers]] at [[Kitty Hawk, North Carolina]].<ref>[https://web.archive.org/web/20180902174126/http://www.thewrightbrothers.org/fivefirstflights.html "The Five First Flights" (archived)]. thewrightbrothers.org, 23 July 2008.</ref> For its voracious consumption of fuel and its maintenance and reliability issues<ref name="Lippincott p.4"/> the Galaxy's aircrews have nicknamed it "FRED", for Fucking{{#tag:ref|Sometimes written as "fantastic".<ref>Goebel, Greg. [http://www.airvectors.net/avc5.html "The Lockheed C-141 Starlifter & C-5 Galaxy"]. ''Air Vectors'', 1 April 14.</ref><ref>Gustin, Emmanuel. [http://web.mit.edu/btyung/www/nickname.html "Aircraft nicknames"]. mit.edu. Retrieved 6 December 2012.</ref>|group=N}} Ridiculous Economic/Environmental Disaster.<ref name="Lippincott p.4">Lippincott 2006, p. 4.</ref><!-- See [[WP:NOTCENSORED]], and [[WP:Offensive material]] -->

[[File:Excavators in a C5.jpg|thumb|left|upright|[[JCB HMEE]] backhoe loader stowed inside a C-5. The C-5 [[loadmaster]]s ensure cargo is secured and balanced before takeoff.]]
Takeoff and landing distance requirements for the plane at maximum-load gross weight are {{convert|8300|ft|m|abbr=on}} and {{convert|4900|ft|m|abbr=on}}, respectively. Its high-flotation [[Landing gear|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 takeoff 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.<ref name="Giants p63">''Air International''. February 1984, p. 63.</ref>

The C-5 features a malfunction detection analysis and recording system to identify errors throughout the aircraft.<ref name="aviationzone" />
The cargo compartment is {{convert|121|ft|m|abbr=on}} long, {{convert|13.5|ft|m|abbr=on}} high, and {{convert|19|ft|m|abbr=on}} wide, or just over {{convert|31000|ft3|m3|abbr=on}}. It can accommodate up to 36 [[463L master pallet]]s 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.{{cn|date=February 2023}}

The C-5 Galaxy is capable of moving nearly every type of military combat equipment, including such bulky items as the Army [[M60 AVLB|armored vehicle launched bridge]], at {{convert|74|ST|t|abbr=on}}, from the United States to any location on the globe;{{cn|date=February 2023}} and of accommodating up to six [[Boeing AH-64 Apache]] helicopters or five [[Bradley Fighting Vehicle]]s at one time.<ref name = 'CBO 46'>Congressional Budget Office 1986, p. 46.</ref>

==Operational history==
[[File:M1 Abrams loaded on a C-5 Galaxy.jpg|thumb|Loading an [[M1A1 Abrams]] tank onto a C-5 Galaxy]]
The first C-5A was delivered to the USAF on 17 December 1969. Wings were built up in the early 1970s at [[Altus Air Force Base|Altus AFB]], Oklahoma; [[Charleston Field|Charleston AFB]], South Carolina; [[Dover Air Force Base|Dover AFB]], Delaware; and [[Travis Air Force Base|Travis AFB]], California. The C-5's first mission was on 9 July 1970, in Southeast Asia during the [[Vietnam War]].<ref>Coughlin, William J. [https://pqasb.pqarchiver.com/latimes/access/662769552.html?dids=662769552:662769552&FMT=ABS&FMTS=ABS:AI&type=historic&date=Jul+10%2C+1970&author=&pub=Los+Angeles+Times&desc=C-5A+in+First+S.+Viet+Flight&pqatl=google "C-5A in first S. Viet flight."] {{Webarchive|url=https://web.archive.org/web/20121104084240/http://pqasb.pqarchiver.com/latimes/access/662769552.html?dids=662769552:662769552&FMT=ABS&FMTS=ABS:AI&type=historic&date=Jul+10,+1970&author=&pub=Los+Angeles+Times&desc=C-5A+in+First+S.+Viet+Flight&pqatl=google |date=4 November 2012}} ''Los Angeles Times'', 10 July 1970.</ref> 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.<ref name="Norton_p43">Norton 2003, pp. 43–44.</ref> In the final weeks of the war, prior to the [[Fall of Saigon]], several C-5s were involved in evacuation efforts. During [[1975 Tân Sơn Nhứt C-5 accident|one such mission]], a C-5A crashed while transporting a large number of orphans, with over 140 killed.<ref name ='viet accid'/><ref name=babyliftrevisited/>

C-5s have also been used to deliver support and reinforce various US allies over the years. During the [[Yom 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 as [[Operation Nickel Grass]].<ref name="Norton_p45">Norton 2003, pp. 45–46.</ref><ref>Dunstan 2007, pp. 56, 88.</ref> The C-5 Galaxy's performance in Israel was such that the Pentagon began to consider further purchases.<ref>[https://pqasb.pqarchiver.com/latimes/access/643418162.html?dids=643418162:643418162&FMT=ABS&FMTS=ABS:AI&type=historic&date=Nov+09%2C+1973&author=&pub=Los+Angeles+Times&desc=C-5+Performance+in+Israel+May+Spur+Pentagon+to+Order+More&pqatl=google "C-5 Performance in Israel may spur Pentagon to order more."] {{Webarchive|url=https://web.archive.org/web/20121104084256/http://pqasb.pqarchiver.com/latimes/access/643418162.html?dids=643418162:643418162&FMT=ABS&FMTS=ABS:AI&type=historic&date=Nov+09,+1973&author=&pub=Los+Angeles+Times&desc=C-5+Performance+in+Israel+May+Spur+Pentagon+to+Order+More&pqatl=google |date=4 November 2012}} ''Los Angeles Times'', 9 November 1973.</ref> The C-5 was regularly made available to support American allies, such as the British-led peacekeeper initiative in [[Zimbabwe]] in 1979.<ref>[https://pqasb.pqarchiver.com/latimes/access/648649042.html?dids=648649042:648649042&FMT=ABS&FMTS=ABS:AI&type=historic&date=Dec+07%2C+1979&author=&pub=Los+Angeles+Times&desc=U.S.+Cargo+Jets+to+Play+Zimbabwe+Role&pqatl=google "U.S. Cargo Jets to play Zimbabwe role."] {{Webarchive|url=https://web.archive.org/web/20121104084317/http://pqasb.pqarchiver.com/latimes/access/648649042.html?dids=648649042:648649042&FMT=ABS&FMTS=ABS:AI&type=historic&date=Dec+07,+1979&author=&pub=Los+Angeles+Times&desc=U.S.+Cargo+Jets+to+Play+Zimbabwe+Role&pqatl=google |date=4 November 2012}} ''Los Angeles Times'', 7 December 1979,</ref>

[[File:USAF MMIII C5 airdrop(Oct 1974).jpg|thumb|left|C-5A Minuteman Air Mobile ICBM Feasibility Demonstration – 24 October 1974]]
On 24 October 1974, the [[Space and Missile Systems Organization]] successfully conducted an [[air-launched ballistic missile]] test, where a C-5A Galaxy aircraft air dropped an {{convert|86000|lb|adj=on||}} [[LGM-30 Minuteman|Minuteman ICBM]] from {{convert|20000|ft|||}} over the Pacific Ocean. The missile descended to {{convert|8000|ft|||}} before its rocket engine fired. The 10-second engine burn carried the missile to {{convert|20000|ft|||}} again before it dropped into the ocean. The test proved the feasibility of launching an intercontinental ballistic missile from the air. Operational deployment was discarded due to engineering and security difficulties, though the capability was used as a negotiating point in the [[Strategic Arms Limitation Talks]].<ref>[http://www.af.mil/information/heritage/milestones.asp?dec=1970-1980&sd=01/01/1970&ed=12/31/1989 "Thursday, 01 January 1970 – Sunday, 31 December 1989."] {{webarchive|url=https://web.archive.org/web/20121018002131/http://www.af.mil/information/heritage/milestones.asp?dec=1970-1980&sd=01%2F01%2F1970&ed=12%2F31%2F1989 |date=18 October 2012}} ''U.S. Air Force, Inside the AF.MIL Heritage section.''</ref><ref>Marti and Sarigul-Klijn. "A Study of Air Launch Methods for RLVs. Doc No. AIAA 2001–4619." Mechanical and Aeronautical Engineering Dept, University of California, Davis, California.</ref> Aircraft 69–0014, "Zero-One-Four" used in the test was retired to the [[Air Mobility Command Museum]] at [[Dover Air Force Base]].<ref>{{cite web|url=http://www.cnn.com/2013/08/09/travel/c5-galaxy-dover-museum-minuteman-missile/index.html|title=The 'radical' nuclear missile test that made history|first=Thom |last=Patterson|publisher=CNN|date=9 August 2013}}</ref>

[[File:Galaxy Antarctica.jpg|thumb|Personnel unload cargo from a C-5 Galaxy at [[Pegasus Field]], an ice runway near [[McMurdo Station]], [[Antarctica]], in 1989.]]
The C-5 has been used for several unusual functions. During the development of the secretive stealth aircraft, the [[Lockheed F-117 Nighthawk]], Galaxies were often used to carry partly disassembled aircraft, leaving no exterior signs as to their cargo.<ref>Jenkins 2001, p. 84.</ref> The C-5 remains the largest aircraft to operate in the Antarctic,<ref>Dole, Ronald D. [http://www.qsl.net/ka1efo/spole.htm "Six Months "On Ice": Living And Working At The Bottom Of The World."] ''KA1EFO ''. Retrieved 23 August 2011.</ref> capable of operating from [[Williams Field]] near [[McMurdo Station]].<ref>[https://www.nsf.gov/od/lpa/news/02/pr0214.htm "Runway Project Clears the Way for Improved Antarctic Airlift."] {{Webarchive|url=https://web.archive.org/web/20230111143210/https://www.nsf.gov/od/lpa/news/02/pr0214.htm |date=11 January 2023 }} National Science Foundation, 20 February 2002. Retrieved 20 January 2007.</ref> The C-5 Galaxy was a major supply asset in the international coalition operations in 1990–91 against [[Iraq]] in the [[Gulf War]].<ref>Evans, David. [https://pqasb.pqarchiver.com/chicagotribune/access/28877430.html?dids=28877430:28877430&FMT=ABS&FMTS=ABS:FT&type=current&date=Aug+24%2C+1990&author=David+Evans&pub=Chicago+Tribune+(pre-1997+Fulltext)&desc=The+Gulf+airlift+has+moved+only+the+tip+of+the+spear&pqatl=google "The Gulf airlift has moved only the tip of the spear."] {{Webarchive|url=https://web.archive.org/web/20121104084329/http://pqasb.pqarchiver.com/chicagotribune/access/28877430.html?dids=28877430:28877430&FMT=ABS&FMTS=ABS:FT&type=current&date=Aug+24,+1990&author=David+Evans&pub=Chicago+Tribune+(pre-1997+Fulltext)&desc=The+Gulf+airlift+has+moved+only+the+tip+of+the+spear&pqatl=google |date=4 November 2012}} ''Chicago Tribune'', 24 August 1990.</ref><ref>Brenner, Elliot. [https://news.google.co.uk/newspapers?id=1XwhAAAAIBAJ&sjid=U4gFAAAAIBAJ&pg=1013,5314370&dq=c-5+cargo&hl=en "Massive airlift, sealift equals moving a town."] ''Daily Gazette'', 22 August 1990.</ref><ref>Chant 2001, p. 47.</ref> C-5s have routinely delivered relief aid and humanitarian supplies to areas afflicted with natural disasters or crisis; multiple flights were made over [[Rwanda]] in 1994.<ref>Plunkett, A.J. [https://pqasb.pqarchiver.com/dailypress/access/85914755.html?dids=85914755:85914755&FMT=ABS&FMTS=ABS:FT&type=current&date=Aug+04%2C+1994&author=A.J.+PLUNKETT+Daily+Press&pub=Daily+Press&desc=MORE+TROOPS+LEAVE+ON+RWANDAN+MISSION&pqatl=google "More troops leave on Rwandan mission."] {{Webarchive|url=https://web.archive.org/web/20121104084340/http://pqasb.pqarchiver.com/dailypress/access/85914755.html?dids=85914755:85914755&FMT=ABS&FMTS=ABS:FT&type=current&date=Aug+04,+1994&author=A.J.+PLUNKETT+Daily+Press&pub=Daily+Press&desc=MORE+TROOPS+LEAVE+ON+RWANDAN+MISSION&pqatl=google |date=4 November 2012}} ''Daily Press'', 4 August 1994.</ref> The C-5 is also used to transport [[Marine One]].<ref name=NatGeo_On_Board>[https://web.archive.org/web/20130126225131/http://channel.nationalgeographic.com/channel/episodes/on-board-marine-one1/video/ "On Board Marine One, Presidential Fleet"]. National Geographic, 2009. Retrieved 5 September 2013.</ref>

The wings on the C-5As were replaced during the 1980s to restore full design capability.<ref name="Norton_p53"/> The USAF took delivery of the first C-5B on 28 December 1985 and the final one in April 1989.<ref name="Norton_p58">Norton 2003, p. 58.</ref> The reliability of the C-5 fleet has been a continued issue throughout its lifetime,<ref>Leary, William M. [https://web.archive.org/web/20010628045844/http://www.airpower.maxwell.af.mil/airchronicles/aureview/1986/sep-oct/leary.html "Strategic Airlift: Past, Present, and Future."] ''Air University Review'', September–October 1986.</ref><ref>Anderson, Brian H. [http://www.stormingmedia.us/02/0223/A022363.html "The Mobility Traid and Challenges for the Operational Commander."] {{Webarchive|url=https://web.archive.org/web/20151208123339/http://www.stormingmedia.us/02/0223/A022363.html |date=8 December 2015}} ''Naval War College Newport'', 5 February 1999, p. 8.</ref> however the C-5M upgrade program seeks in part to address this issue.<ref name="afm_200401_stg"/> Their strategic airlift capacity has been a key logistical component of U.S. military operations in [[War in Afghanistan (2001–present)|Afghanistan]] and [[Iraq War|Iraq]]. Following an incident during [[Operation Iraqi Freedom]] where one C-5 was damaged by a projectile, the installation of defensive systems has become a stated priority.<ref>Government Accountability Office 2006, pp. 125–156.</ref>

===Upgrades to C-5M Super Galaxy<span class="anchor" id="C-5M"></span>===
[[File:C-5M Cockpit.jpg|thumb|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,<ref name="AFviab">Jablonski, David A. [https://www.af.mil/News/Article-Display/Article/136524/air-force-fleet-viability-board-releases-c-5a-assessment/ "Air Force Fleet Viability Board releases C-5A assessment"]. ''Air Force Print News'', 15 July 2004.</ref> [[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.<ref>[https://web.archive.org/web/20060322013056/http://www.codeonemagazine.com/events/apr_03/apr03_events08.html "First Flight For AMP C-5"]. ''Code One Magazine'', April 2003.</ref>

The Reliability Enhancement and Re-engining Program (RERP) began in 2006. It includes fitting new [[GE-Aviation|General Electric]] [[General Electric CF6|F138-GE-100]] (CF6-80C2) engines, pylons and auxiliary power units, and upgrades to aircraft skin and frame, landing gear, cockpit and pressurization systems.<ref name="afm_200401_stg" /><ref name="HookerHoyle2006">{{cite journal |last1=Hooker |first1=John |last2=Hoyle |first2=David |last3=Bevis |first3=Dwayne |year=2006 |title=The Application of CFD for the Aerodynamic Development of the C-5M Galaxy |journal=44th AIAA Aerospace Sciences Meeting and Exhibit |doi=10.2514/6.2006-856 |isbn=978-1-62410-039-0}}</ref> Each CF6 engine produces 22% more thrust ({{convert|50000|lbf|kN|abbr=on|disp=or}}),<ref>[https://web.archive.org/web/20090327102718/http://www.lockheedmartin.com/data/assets/aeronautics/products/c5/A07-20536GC-5PC.pdf "C-5 modernization program"]. Lockheed Martin. Retrieved 21 January 2010.</ref> providing a 30% shorter takeoff, a 38% higher climb rate to initial altitude, an increased cargo load and a longer range.{{specify|date=June 2015}}<ref name="afm_200401_stg" /><ref name="lm_C-5M_extends">[http://www.lockheedmartin.com/us/news/press-releases/2006/may/LOCKHEEDMARTINC5MSUPERGALAXYEXPANDS.html "Lockheed Martin C-5M 'Super Galaxy' Expands U.S. Air Force 'Global Reach' Capability at Lower Cost"] {{webarchive|url=https://web.archive.org/web/20130103184336/http://www.lockheedmartin.com/us/news/press-releases/2006/may/LOCKHEEDMARTINC5MSUPERGALAXYEXPANDS.html|date=3 January 2013}}. Lockheed Martin, 16 May 2006.</ref> Upgrades to all fifty C-5Bs and both C-5Cs were completed by August 2018.<ref name=":0" /> These aircraft are now designated ''C-5M Super Galaxy.''<ref name="afpn_20061120">[https://www.af.mil/News/Article-Display/Article/129001/second-c-5m-super-galaxy-takes-flight/ "Second C-5M Super Galaxy takes flight"]. U.S. Air Force, 20 November 2006.</ref>

The C-5 AMP and RERP modernization programs plan to raise [[availability|mission-capable rate]] to a minimum goal of 75%.<ref name="afm_200401_stg" /> Over the next 40 years, the U.S. Air Force estimates the C-5M will save over $20&nbsp;billion.<ref name="strong">McGowan, Laura. [https://www.afmc.af.mil/news/story?storyID=123022249 "C-5 still going strong."]  ''US Air Force'', 21 June 2006.</ref> The first C-5M conversion was completed on 16 May 2006 and C-5Ms began test flights at [[Dobbins Air Reserve Base]] in June 2006.<ref name="strong" /> In 2008, the USAF decided to convert remaining C-5Bs and C-5Cs into C-5Ms with avionics upgrades and re-engining.<ref name="FG_part_re-engine">Warick, Graham. [http://www.flightglobal.com/articles/2008/02/15/221590/pentagon-cancels-re-engining-of-usafs-older-lockheed.html "Pentagon cancels re-engining of USAF's older Lockheed C-5s."] ''FlightGlobal'', 15 February 2008.</ref> The C-5As will receive only the avionics upgrades.<ref name="FG_part_re-engine" /><ref>[https://www.af.mil/News/Article-Display/Article/124337/air-force-c-5-galaxy-modernization-program-certified/ "Air Force C-5 Galaxy modernization program certified."] ''U.S. Air Force,'' 15 February 2008.</ref> The last of 52 C-5Ms was delivered to Air Mobility Command in August 2018.<ref>{{Cite web | url=https://www.businessinsider.com/air-force-c-5m-super-galaxy-upgrade-done-will-stay-in-air-until-2040s-2018-8 |title = After 17 years of upgrades, the Air Force's biggest plane is ready to stay in the air for decades| website=[[Business Insider]] |date = 14 August 2018}}</ref>

[[File:C-5 Galaxy - 060505-F-0000J-002.jpg|thumb|A C-5 taking off from [[Robins AFB]]]]
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.<ref>Weinberger, Sharon. [https://web.archive.org/web/20160529072408/https://www.highbeam.com/doc/1G1-111281311.html "Congress Moves To Limit C-5A Retirement."] ''Defense Daily'', 14 November 2003.</ref> 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 the [[Warner Robins Air Logistics Center]] (WR-ALC) for tear down and inspection to evaluate structural integrity and estimate the remaining life for the fleet.<ref>{{cite web |url=http://www.amarcexperience.com |title=AMARC Experience |website= AMARC Experience}}</ref>

The U.S. Air Force began to receive refitted C-5M aircraft in December 2008.<ref>Trimble, Stephen. [http://www.flightglobal.com/articles/2008/12/11/320013/picture-lockheed-delivers-first-upgraded-c-5m-super.html "Lockheed delivers first upgraded C-5M Super Galaxy."] ''Flight International'', 11 December 2008.</ref> Full production of C-5Ms began in the summer of 2009.<ref>[https://www.bloomberg.com/apps/news?pid=conewsstory&refer=conews&tkr=LMT%3AUS&sid=a80TQify8P3k "Lockheed Martin delivers third C-5M Super Galaxy to United States Air Force."] ''Bloomberg'', 27 February 2009.</ref> In 2009, the Congressional ban on the retirement of C-5s was overturned.<ref>Trimble, Stephen. [http://www.flightglobal.com/articles/2009/09/11/332171/more-c-17-sales-possible-after-c-5a-retirement-ban-lifted.html "More C-17 sales possible after C-5A retirement ban lifted."] ''Flight International'', 11 September 2009.</ref> The Air Force seeks to retire one C-5A for every 10 new [[C-17 Globemaster III|C-17s]] ordered.<ref>Rolfsen, Bruce, [http://www.airforcetimes.com/news/2010/01/airforce_aircraft_budget_011010w/ "C-5A swap for new C-17s has hitch."] ''Air Force Times'', 12 January 2010.</ref> In October 2011, the [[445th Airlift Wing]] based at [[Wright-Patterson Air Force Base]] replaced all remaining C-5s with C-17s.<ref>[https://www.445aw.afrc.af.mil/News/story/id/123274598/ "445th C-5 era comes to an end"]  ''445th Airlift Wing Public Affairs,'' 4 October 2011.</ref> The C-5M reached [[initial operating capability]] (IOC) on 24 February 2014 with 16 aircraft delivered.<ref>[http://www.upi.com/Business_News/Security-Industry/2014/02/24/Upgraded-C-5M-Super-Galaxies-gain-IOC-designation/UPI-59271393272844/?spt=rln&or=2 Upgraded C-5M Super Galaxies gain IOC designation] – Upi.com, 24 February 2014.</ref>

On 13 September 2009, a C-5M set 41 new records and flight data was submitted to the [[National Aeronautic Association]] for formal recognition. The C-5M had carried a payload of {{convert|176610|lb|kg|abbr=on}} to over {{convert|41100|ft|m|abbr=on}} 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 {{convert|2000|m|ft|abbr=on|order=flip|sigfig=4}} was broken. The aircraft was in the category of {{convert|250000|to|300000|kg|lb|abbr=on|order=flip|sigfig=4}} with a takeoff weight of {{convert|649680|lb|kg|abbr=on}} including payload, fuel, and other equipment.<ref>[http://www.lockheedmartin.com/us/news/press-releases/2009/september/1LockheedMartinC-5MSuperG.html "Lockheed Martin C-5M Super Galaxy Sets World Aviation Records."] ''Lockheed Martin'', 15 September 2009.</ref>

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.<ref>{{cite web|url=https://www.airforcetimes.com/articles/air-mobility-command-stands-down-c-5-flying-operations-at-dover-afb|title=Air Mobility Command stands down C-5 flying operations at Dover AFB|first=Charlsy|last=Panzino|date=7 August 2017|website=Air Force Times}}</ref> The last TF39-powered C-5 flew in late 2017.<ref>{{cite web |url=https://www.westover.afrc.af.mil/News/Article-Display/Article/1303782/and-then-there-were-none-the-final-c-5a-departs-westover-arb-for-retirement/ |title = And then there were none, the final C-5A departs Westover ARB for retirement > Westover Air Reserve Base > Article Display |date=8 September 2017|last=Smith |first=Hanna}}</ref><ref>{{cite web |last1=Balik |first1=Roland |title=An era of Dover-built TF39 engines throttles down |url=https://www.amc.af.mil/News/Article-Display/Article/785826/an-era-of-dover-built-tf39-engines-throttles-down/ |website=Air Mobility Command |access-date=9 February 2023 |date=12 April 2016}}</ref>

==Variants==
===C-5A===
[[File:C-5A Cockpit.jpg|thumb|Instrument panel of a 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 [[aluminum alloy]] that did not exist during the original production.{{cn|date=February 2023}} 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.<ref>{{cite web|url=http://www.amarcexperience.com/ui/index.php?option=com_content&view=article&id=5&catid=16&dbsource=typelist&dbtype=C005A&dbpage=1&dbletter=L|title=AMARC Experience – Search the Database|website=amarcexperience.com}}</ref> The last operational C-5A was retired on 7 September 2017.<ref>{{cite web|url=https://www.dvidshub.net/video/549245/last-c-5a-galaxy-arrives-amarg|title=Last C-5A Galaxy Arrives at AMARG|website=dvidshub.net}}</ref>

===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. Fifty examples of the new variant were delivered to the U.S. Air Force from 1986 to 1989.<ref>Miller 2003, p. 53.</ref>

===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.<ref name="Norton_p62">Norton 2003, pp. 62, 78.</ref> 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-5D===
Proposed during the 1990s Non-Developmental Airlift Aircraft (NDAA) program as an alternative to further purchases of the [[McDonnell Douglas C-17 Globemaster III]] as well as a replacement for older C-5As. The C-5D was to have [[GE-Aviation|General Electric]] [[General Electric CF6|F138-GE-100]] (CF6-80C2) engines, improved avionics and significantly improved reliability and maintainability, although it could not use austere runways or conduct [[airdrop]] 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.<ref>FlightGlobal.[https://www.flightglobal.com/lockheed-chooses-cf6-80c2-for-c-5d/17021.article "Lockheed chooses CF6-80C2 for C-5D"]. Flightglobal.com </ref>

===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 travelers, 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).<ref>[https://web.archive.org/web/20070603201214/http://www.time.com/time/magazine/article/0,9171,712157,00.html "Aircraft: The Biggest Bird"]. ''[[Time (magazine)|Time]]'', 12 July 1968.</ref> 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 [[Lockheed L-1011 TriStar|L-1011]], which led to the governmental rescue of the company.<ref>{{usurped|1=[https://web.archive.org/web/20110402070028/http://www.doraplane.com/index_files/Page585.htm "Lockheed L-500 Galaxy proposed UAL colors, c. 1968"]}}.  doraplane.com. Retrieved 3 January 2011.{{rs|date=July 2022}}</ref>

===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 favor of the [[Boeing 747]].<ref>{{Cite web|url=http://up-ship.com/blog/?p=3847|title=Shuttling the Shuttle: Twin fuselage C-5 Galaxy – The Unwanted Blog|website=up-ship.com}}</ref><ref>{{Cite web|title=Tails through time|date=24 January 2011|url=http://aviationtrivia.blogspot.co.uk/2011/01/747-shuttle-carrier-aircraft-sca.html}}</ref>

[[File:C5 galaxy.jpg|thumb|People in line to enter the 445th Airlift Wing's first C-5A Galaxy in 2005]]
[[File:Lockheed C-5B Galaxy (L-500), USA - Air Force AN0568811.jpg|thumb|C-5B Galaxy at [[Rhein-Main AB]]]]
[[File:C-5B Arrival At CYQB.jpg|thumb|A C-5 landing at [[Québec City Jean Lesage International Airport]] (CYQB)]]
[[File:KC-46 Refuels C-5M 4-2019.jpg|thumb|A [[Boeing KC-46 Pegasus]] refuels a C-5M Galaxy from Travis AFB over California, April 2019.]]
[[File:DSRV 2 Avalon 1.jpg|thumb|Loading a [[Mystic-class deep-submergence rescue vehicle]] onto a C-5]]
[[File:CH-53E loaded on C-5A Davis-Monthan 2005.jpg|thumb|Loading a [[Super Stallion]] on a C-5A]]

==Operators==
;{{USA}}
''[[United States Air Force]]'' – 52 C-5Ms in service as of August 2018<ref>[https://www.businessinsider.com/air-force-c-5m-super-galaxy-upgrade-done-will-stay-in-air-until-2040s-2018-8 "After 17 years of upgrades, the Air Force's biggest plane is ready to stay in the air for decades"]. ''Business Insider'', 13 August 2018.</ref>

[[Air Mobility Command]]
*[[60th Air Mobility Wing]] – [[Travis Air Force Base]], California
::[[22nd Airlift Squadron]], 1972–present

*[[436th Airlift Wing]] – [[Dover Air Force Base]], Delaware
::[[9th Airlift Squadron]], 1971–present

[[Air Force Reserve Command]]
*[[349th Air Mobility Wing]] (Associate) – [[Travis Air Force Base]], California
::[[312th Airlift Squadron]], 1973–present

*[[413th Flight Test Group]] – [[Robins AFB]], [[Georgia (U.S. state)|Georgia]]
::[[339th Flight Test Squadron]], 1998–present

*[[433d Airlift Wing]] – [[Kelly Field Annex]], Texas
::[[68th Airlift Squadron]], 1985–present
::[[356th Airlift Squadron]], 2007–present

*[[439th Airlift Wing]] – [[Westover Air Reserve Base]], Massachusetts
::[[337th Airlift Squadron]], 1987–present

*[[512th Airlift Wing]] (Associate) – [[Dover Air Force Base]], Delaware
::[[709th Airlift Squadron]], 1973–present

===Former operators===
[[Military Airlift Command]]/[[Air Mobility Command]]
*60th Military Airlift Wing/Air Mobility Wing – [[Travis Air Force Base]], California
::[[21st Airlift Squadron]], 1993–2006
::75th Military Airlift Squadron, 1970–1992
*436th Military Airlift Wing/Airlift Wing – [[Dover Air Force Base]], Delaware
::3d Military Airlift Squadron/Airlift Squadron, 1973–2007
::31st Military Airlift Squadron/Airlift Squadron, 1989–1994
*437th Military Airlift Wing – [[Charleston Air Force Base]], South Carolina
::3d Military Airlift Squadron, 1970–1973
*443d Military Airlift Wing – [[Altus Air Force Base]], Oklahoma
::56th Military Airlift Squadron, 1969–1992
*[[97th Air Mobility Wing]] – Altus AFB, Oklahoma
::56th Military Airlift/[[56th Airlift Squadron]], 1992–2007

[[Air Force Reserve]]
*349th Military Airlift Wing/Air Mobility Wing (Associate) – Travis Air Force Base, California
::301st Military Airlift Squadron/Airlift Squadron, 1973–2006
*445th Military Airlift Wing/[[445th Airlift Wing]] – [[Wright-Patterson AFB]], [[Ohio]]
::89th Airlift Squadron, 2006–2012
*512th Military Airlift Wing/Airlift Wing(Associate) – Dover Air Force Base, Delaware
::326th Military Airlift Squadron/Airlift Squadron, 1973–2007
[[Air National Guard]]
*105th Military Airlift Group/Military Airlift Wing/[[105th Airlift Wing]] – [[Stewart ANGB]], New York
::137th Military Airlift Squadron/Airlift Squadron, 1985–2012
*164th Military Airlift Wing/Airlift Wing – [[Memphis, Tennessee]]
::155th Military Airlift Squadron/Airlift Squadron, 2004–2013
*167th Military Airlift Wing/[[167th Airlift Wing]] – [[Martinsburg, West Virginia]]
::167th Military Airlift/[[167th Airlift Squadron]], 2006–2015

==Incidents and accidents==
[[File:Shemya700446b.jpg|thumb|C-5A after crash landing at [[Eareckson Air Station|Shemya AFB]], [[Alaska]], July 1983]]
[[File:C-5 Galaxy crash 2006-04-03 F-0859C-018.jpg|thumb|Emergency responders at the scene of a C-5B crash at [[Dover Air Force Base|Dover AFB]], [[Delaware]], April 2006]]
[[File:Airman from the 436th Aerial Port Squadron and 9th Airlift Squadronload a C-5 Galaxy flight deck on a C-5 for transport to Robins AFB.jpg|thumb|The flight deck from the C-5B crash at [[Dover Air Force Base|Dover AFB]] in April 2006 being loaded into another C-5]]

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.

===Notable accidents===
* On 27 May 1970, C-5A AF Serial No. 67-0172 was destroyed during a ground fire at [[Palmdale, California]], after an Air Turbine Motor started backwards and quickly overheated, setting the hydraulic system on fire and consuming the aircraft. The engines were not running at the time of the fire. Five crew escaped, and seven firefighters suffered minor injuries fighting the blaze.<ref>''San Bernardino Sun'', 28 May 1970.</ref><ref name="AF2006">[https://www.af.mil/News/Article-Display/Article/131428/c-5-crash-doesnt-diminish-historians-view-of-aircraft/ "C-5 crash doesn't diminish historian's view of aircraft."] ''US Air Force'', 4 April 2006.</ref>
* On 17 October 1970, C-5A AF Serial No. 66-8303 was destroyed during a ground fire at the Lockheed Aircraft plant at [[Dobbins Air Reserve Base|Dobbins AFB]] in Marietta, Georgia. The fire started during maintenance in one of the aircraft's 12 fuel cells. One worker was killed and another injured. This was the first C-5 aircraft produced.<ref name="AF2006"/><ref>{{cite news |date=18 October 1970 |title=Halt to C5 Program Sought After $50 Million Blaze |url=https://news.google.com/newspapers?id=uApaAAAAIBAJ&sjid=ZksNAAAAIBAJ&pg=5650%2C2926835 |work=[[The Victoria Advocate]] |issue=165 |agency=[[Associated Press]] |page=16A |access-date=23 September 2024 |via=[[Google News Archive]] }}</ref>
* On 27 September 1974, C-5A Serial No. 68-0227 crashed after over-running the runway at [[Clinton, Oklahoma]], Municipal Airport during an emergency landing following a serious landing gear fire. The crew mistakenly aligned the aircraft for the visual approach into the wrong airport, landing at Clinton Municipal Airport, which has a {{convert|4400|ft|m|abbr=on}} runway, instead of the airfield at [[Clinton-Sherman Industrial Airpark]] (former [[Clinton-Sherman Air Force Base]]), which has a {{convert|13500|ft|m|abbr=on}} runway. This was the first operational loss of a C-5 Galaxy.<ref name="AF2006"/>
* On 4 April 1975, C-5A Serial No.68-0218 [[1975 Tân Sơn Nhứt C-5 accident|crashed]] while carrying orphans out of [[Vietnam]] during [[Operation Babylift]]. This accident is one of the most notorious C-5 accidents to date.<ref name='viet accid'>{{cite news |date=4 April 1975 |title=Orphan Plane Crashes |url=https://news.google.com/newspapers?nid=PZE8UkGerEcC&dat=19750404&printsec=frontpage |work=[[The Evening Independent]] |issue=131 |agency=[[Associated Press]] |page=1A |access-date=23 September 2024 |via=[[Google News Archive]] }}</ref> The crash occurred while trying to make an emergency landing at [[Tan Son Nhut Air Base]], [[Ho Chi Minh City|Saigon]], following a rear pressure door lock failure in flight.<ref name="AF2006"/><ref>{{cite news |date=4 April 1975 |title=305 aboard giant craft; 100 survive |url=https://news.google.com/newspapers?id=BBIQAAAAIBAJ&sjid=04wDAAAAIBAJ&pg=6029%2C4736760 |work=[[Boca Raton News]] |issue=106 |agency=[[United Press International]] |pages=1A–2A |access-date=23 September 2024 |via=[[Google News Archive]] }}</ref> 144 people (including 78 children) were killed out of the 313 aboard (243 children, 44 escorts, 16 flight crew and 10 medical crew).<ref name=babyliftrevisited>{{Cite web|url=https://babyliftrevisited.typepad.com/babylift_revisited/2006/07/the_crew_of_the.html|title=THE CREW OF THE C-5|website=Babylift revisited}}</ref> Use of the C-5 was heavily restricted for several months following the high-profile accident.<ref>[https://select.nytimes.com/gst/abstract.html?res=FA0B15F93F55157493C0A8178FD85F418785F9 "Airforce imposes curbs on C-5 use."] ''The New York Times'', 12 April 1975.</ref>
* On 31 July 1983, C-5A Serial No. 70-0446 crashed while landing at the former [[Shemya Air Force Base]] on [[Shemya]] Island in [[Alaska]]. The C-5 approached below the glide slope in heavy fog, hit landing light poles and an embankment short of the runway, stopping at the 5,000-foot mark on the runway with the nose gear at the side of the runway embankment. Structural damage was extensive and the two aft main landing gear bogies were sheared from the aircraft. There were no fatalities. A joint USAF–Lockheed team made repairs, enabling a ferry flight from Shemya to the Lockheed plant in Marietta, Georgia, later that year. There, the aircraft was dubbed ''Phoenix II'' and permanent repair efforts got under way. In addition to the structural repairs, the aircraft also received an improved landing gear system (common to the then-new C-5B), wing modification, and a color weather radar upgrade. The aircraft was returned to service.<ref name="Lippincott_p35">Lippincott 2006, p. 35.</ref>
* In July 1983, C-5A Serial No. 68-0216 landed [[Belly landing|gear up]] at [[Travis Air Force Base]], California. There were no injuries. The accident occurred while the crew was performing touch-and-go landings, and did not lower the landing gear during the final approach of the day. The aircraft received significant damage to the lower fuselage, ramp, clamshell doors, and main landing gear pods. The C-5A was later flown to Marietta for repairs. While there, the aircraft was selected to be the first C-5A converted to the C-5C configuration.<ref name="Lippincott_p28">Lippincott 2006, p. 28.</ref>
* On 29 August 1990, C-5A Serial No. 68-0228 crashed following an engine failure shortly after take-off. The aircraft took off from [[Ramstein Air Base]] in Germany in support of [[Gulf War#Operation Desert Shield|Operation Desert Shield]]. It was flown by a nine-member reserve crew from the [[68th Airlift Squadron]], [[433d Airlift Wing]] based at [[Kelly Field Annex|Kelly AFB]], Texas.<ref>[http://nl.newsbank.com/nl-search/we/Archives?p_product=AASB&p_theme=aasb&p_action=search&p_maxdocs=200&p_topdoc=1&p_text_direct-0=0EAD8B8D41D0425E&p_field_direct-0=document_id&p_perpage=10&p_sort=YMD_date:D&s_trackval=GooglePM "San Antonio air base mourns reservists killed in C-5 crash."] ''Austin American-Statesman'', 30 August 1990.</ref> As the aircraft started to climb off the runway, one of the [[Thrust reversal|thrust reversers]] suddenly deployed. This resulted in loss of control of the aircraft and the subsequent crash. Of the 17 people on board, only four survived the crash.<ref>[http://nl.newsbank.com/nl-search/we/Archives?p_product=NewsLibrary&p_multi=DSNB&d_place=DSNB&p_theme=newslibrary2&p_action=search&p_maxdocs=200&p_topdoc=1&p_text_direct-0=0F35FDF935E4EA6A&p_field_direct-0=document_id&p_perpage=10&p_sort=YMD_date:D&s_trackval=GooglePM "U.S. plane crashes, killing 13."] ''Deseret News'', 29 August 1990.</ref> All four were in the rear troop compartment. The sole crew member to survive, Staff Sgt. Lorenzo Galvan Jr., was awarded the [[Airman's Medal]] for his actions in evacuating the survivors from the wreckage.<ref name="AF2006"/>
* On 3 April 2006, C-5B Serial No. 84-0059 crashed following a cockpit indication that the thrust reverser on No. 2 engine was not locked. The crew shut down No. 2 engine as a safeguard. The C-5B assigned to the [[436th Airlift Wing]] and flown by a reserve crew from the [[709th Airlift Squadron]], [[512th Airlift Wing]] crashed about {{convert|2000|ft|m|abbr=on}} short of the runway while attempting a heavyweight emergency landing at [[Dover Air Force Base]], [[Delaware]]. The aircraft had taken off from Dover 21 minutes earlier and reported an in-flight emergency ten minutes into the flight. All 17 people aboard survived, but two sustained serious injuries. The Air Force's accident investigation board report concluded the cause to be human error, in particular the crew had been manipulating the throttle of the (dead) number-two engine as if it were still running while keeping the (live) number-three engine at idle. The situation was further worsened by the crew's decision to use a high flap setting that increased drag beyond normal two-engine capabilities.<ref>[https://www.dover.af.mil/News/story/storyID/123022236/ "C-5 accident investigation board complete."]  ''US Air Force'', 13 June 2006.</ref><ref>[https://www.youtube.com/watch?v=fI5xTmmPbsY "USAF Crash Investigation Video."] YouTube.</ref> The aircraft was one of the first to receive the new avionics and glass flight displays for C-5 Avionics Modernization Program (AMP).<ref>[https://archive.today/20130811154822/http://www.delawareonline.com/article/20060614/NEWS/60614001/Air-Force-blames-crew-C-5-crash#selection-2785.0-2785.239 "Air Force blames crew for C-5 crash"] ''DelawareOnline'', 14 June 2006.</ref> This accident led to a redesign of the cockpit engine displays, particularly the visual indicators of a non-active engine.<ref>[http://pro.sagepub.com/content/54/1/65.abstract "Pilot Performance Based Selection of Engine Display Features."] ''Proceedings of the Human Factors and Ergonomics Society Annual Meeting'', Vol. 54, no. 1, September 2010, pp. 65–69.</ref> The aircraft was declared a total hull-loss and the airframe was scrapped, but the forward fuselage became a C-5 AMP test bed.<ref name="afl_840059_scrap">Langley, Nicole. [https://www.af.mil/News/Article-Display/Article/128325/gone-with-the-wings-c-5-removal-process-in-full-swing/ "Gone with the wings: C-5 removal process in full swing."] ''US Air Force'', 19 January 2007.</ref>

==Aircraft on display==
* C-5A, AF Ser. No. 70-0451, has been delivered to the [[Travis Air Force Base Heritage Center]] at [[Travis Air Force Base]] for future display. This is the penultimate operational C-5A,<ref>{{cite web|title=Travis Heritage Center acquires AF's largest static display|url=https://www.travis.af.mil/News/Article/1264302/travis-heritage-center-acquires-afs-largest-static-display/|website=Travis Air Force Base|date=August 2017 |access-date=14 November 2017}}</ref> with the last operational C-5A delivered to [[Davis-Monthan Air Force Base]] for spare parts.<ref>{{cite web|title=Off to the Boneyard for Westover's last C-5A|url=http://www.recorder.com/C5-hg-090817-12358101|website=Greenfield Recorder|access-date=14 November 2017|date=7 September 2017}}</ref> However, as display space could not be found, it was decided to scrap the aircraft which is currently being conducted.{{cn|date=April 2024}}
* C-5A, AF Ser. No. 69-0014, is on display at the [[Air Mobility Command Museum]] at [[Dover Air Force Base]], [[Delaware]]. This is the first C-5 aircraft to go on museum display.<ref>[http://www.airforcetimes.com/article/20131104/NEWS/311040018/C-5-goes-display-AMC-museum C-5 goes on display at AMC museum] ''Air Force Times''</ref><ref>{{cite web|title=C-5A Galaxy|url=http://amcmuseum.org/at-the-museum/aircraft/c-5a-galaxy|website=Air Mobility Command Museum|publisher=AMC Museum Foundation, Inc.|access-date=31 July 2017}}</ref>

==Specifications (C-5M)==
[[File:Lockheed C-5 Galaxy 3-view line drawing.jpg|thumb|Drawing lines]]
[[File:C5 Galaxy nose.jpg|thumb|A detail of the C-5's nose assembly raised for loading and unloading]]
[[File:USAF C-5 Galaxy Engine.jpg|thumb|A [[General Electric TF39]] turbofan engine]]
[[File:A CH-47F Chinook helicopter is unloaded from a C-5M Super Galaxy.jpg|thumb|Unloading one of two [[CH-47 Chinook|Chinook]] helicopters from a C-5M ''Super Galaxy'']]

{{Aircraft specs
|ref= Quest for Performance,<ref>Loftin, L.K., Jr. [http://www.hq.nasa.gov/pao/History/SP-468/cover.htm "NASA SP-468: Quest for Performance: The Evolution of Modern Aircraft."] {{Webarchive|url=https://web.archive.org/web/20060613210139/http://www.hq.nasa.gov/pao/History/SP-468/cover.htm |date=13 June 2006 }} ''NASA'', 1985.</ref> International Directory of Military Aircraft,<ref>Frawley, Gerald. ''The International Directory of Military Aircraft, 2002/2003''. Fishwick, Act, Australia: Aerospace Publications, 2002. {{ISBN|1-875671-55-2}}.</ref> and USAF fact sheet<ref name=USAF_fact_sht>[https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104492/c-5-abc-galaxy-c-5m-super-galaxy/ "C-5 A/B/C Galaxy and C-5M Super Galaxy fact sheet."] ''US Air Force'', January 2014. Retrieved 29 January 2014.</ref>
|prime units?=kts
<!--   General characteristics
-->
|crew=<br/>
** 7 typical (Aircraft Commander, First Pilot, 2 Flight Engineers, 3 Loadmasters);
** 4 minimum (pilot, copilot, two flight engineers){{#tag:ref|Loadmasters are not needed when flying without cargo.<ref name=AFMAN/>|group=N}}
** 8 when augmented (Aircraft Commander, 2 First Pilots, 2 Flight Engineers, 3 Loadmasters)<ref name=AFMAN>{{cite book |url=https://static.e-publishing.af.mil/production/1/af_a3/publication/afman11-2c-5v3/afman11-2c-5v3.pdf |title=AIR FORCE MANUAL 11-2C-5, VOLUME 3 |page=11 |date=20 October 2022}}</ref>
|capacity=<br/>
** 36 master pallets [[463L master pallet|463L]], {{cvt|281000|lb|0}}<ref name="af.mil fact sheet">{{Cite web|url=https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104492/c-5m-super-galaxy/|title=C-5M Super Galaxy|website=U.S. Air Force}}</ref>
|length ft=247
|length in=1
|length note=
|span ft=222
|span in=9
|span note=
|height ft=65
|height in=1
|height note=
|wing area sqft=6200
|wing area note=
|aspect ratio=<!-- sailplanes -->
|airfoil='''root:''' [[NACA airfoil|NACA 0012.41 mod]]; '''tip:''' [[NACA airfoil|NACA 0011 mod]]<ref name="Selig">{{cite web |last1=Lednicer |first1=David |title=The Incomplete Guide to Airfoil Usage |url=https://m-selig.ae.illinois.edu/ads/aircraft.html |website=m-selig.ae.illinois.edu |access-date=16 April 2019}}</ref>
|empty weight lb=380000
|empty weight note=
|gross weight lb=<!-- 555000 Not sure where this value comes from. -->
|gross weight note=
|max takeoff weight lb=840000
|max takeoff weight note=<ref group=N>Exceeds normal recommended peacetime max takeoff weight.{{citation needed|date=October 2016}}</ref>
|fuel capacity= 341,446 lb (154,880 kg); {{cvt|51150|USgal|impgal L}}
|more general=
<!--   Powerplant
-->
|eng1 number=4
|eng1 name=[[General Electric CF6-80C2|General Electric F138-100]]
|eng1 type=[[turbofan]] engines
|eng1 lbf=51000
|eng1 note=
<!--   Performance
-->
|max speed kts=462
|max speed note=
|max speed mach=0.79
|cruise speed kts=450
|cruise speed note= / Mach 0.77<!--based on official speed 518 mph, and Mach 0.77 as normal cruise speed, it represents -50&nbsp;°C surrounding temperature, sonic speed is 1,082&nbsp;km/h-->
|stall speed kts=
|stall speed note=
|never exceed speed kts=
|never exceed speed note=
|minimum control speed kts=
|minimum control speed note=
|range nmi=4800
|range note= with a {{cvt|120000|lb|kg|0}} payload, {{cvt|2300|nmi|0}} at maximum cargo capacity<ref name="af.mil fact sheet" />
|combat range nmi=
|combat range note=
|ferry range nmi=7000
|ferry range note=with no cargo on board.
|endurance=<!-- if range unknown -->
|ceiling ft=41000
|ceiling note=at {{cvt|750000|lb|kg|0}}
|g limits=<!-- aerobatic -->
|roll rate=<!-- aerobatic -->
|climb rate ftmin=2100
|climb rate note=
|time to altitude=
|wing loading lb/sqft=
|wing loading note=
|fuel consumption lb/mi=
|power/mass=
|thrust/weight=0.26

|more performance=<br/>
*'''Take-off run:''' {{cvt|5400|ft}}
*'''Landing run:''' {{cvt|3600|ft}}
|avionics=
}}

==See also==
{{Portal|Aviation}}
{{aircontent
|see also=
|related=
|similar aircraft=<!-- aircraft with similar role, era, and capability (For C-5 primarily for large military cargo planes and freighters, not passenger airliners.) -->
* {{annotated link|Antonov An-124 Ruslan}}
* {{annotated link|Antonov An-225 Mriya}}
* {{annotated link|Boeing C-17 Globemaster III}}
* {{annotated link|Boeing 747}}
* [[List of active United States military aircraft]]
* [[List of Lockheed aircraft]]
}}

==References==

===Notes===
{{Reflist|group=N}}

===Citations===
{{Reflist}}

===Bibliography===
{{Refbegin}}
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* "The Giants of Georgia". ''[[Air International]]'', Vol. 26, No. 2, February 1984, pp.&nbsp;61–68, 87–90. {{ISSN|0306-5634}}.
* Government Accountability Office. ''Military Readiness: DOD Needs to Identify and Address Gaps and Potential Risks in Program Strategies and Funding Priorities for Selected Equipment.'' Darby, Pennsylvania: DIANE Publishing, 2006. {{ISBN|1-4223-0444-2}}.
* [https://books.google.com/books?id=GWPeCUdo8iwC ''Improving Strategic Mobility: The C-17 Program and Alternatives.''] Washington, D.C.: Congressional Budget Office, United States Congress, September 1986. {{ISBN|1-4379-0071-2}}.
* Irving, Clive. ''Wide Body: The Triumph of the 747''. New York: W. Morrow, 1993. {{ISBN|0-688-09902-5}}.
* Jenkins, Dannis J. ''Lockheed Secret Projects: Inside the Skunk Works''. St. Paul, Minnesota: Zenith Imprint, 2001. {{ISBN|0-7603-0914-0}}.
* Miller, David. ''Conflict Iraq: Weapons and Tactics of the US and Iraqi Forces''. St. Paul, Minnesota: Zenith Imprint, 2003. {{ISBN|0-7603-1592-2}}.
* Nalty, Bernard C. ''Winged Shield, Winged Sword 1950–1997: A History of the United States Air Force''. Minerva Group, 2003. {{ISBN|1-4102-0902-4}}.
* Lippincott, Richard. ''C-5 Galaxy in Action''. Carrollton, Texas: Squadron/Signal Publications, 2006. {{ISBN|0-89747-504-6}}.
* Norton, Bill. ''Lockheed Martin C-5 Galaxy''. North Branch, Minnesota: Specialty Press, 2003. {{ISBN|1-58007-061-2}}.
* Philips, Warren F. ''Mechanics of Flight''. Hoboken, New Jersey: John Wiley and Sons, 2004. {{ISBN|0-471-33458-8}}.
* Reed, Chris. ''Lockheed C-5 Galaxy''. Atglen, Pennsylvania: Schiffer Publishing, 2000. {{ISBN|0-7643-1205-7}}.
* {{Citation |last=Rice |first=Berkeley |year=1971 |title=The C-5A Scandal |publisher=Houghton Mifflin |url=https://books.google.com/books?id=jughAAAAMAAJ |oclc=785825369 |postscript=.|isbn=9780395121030}}
* Tillman, Barrett. [https://books.google.com/books?id=v6VpE_jCzecC ''What We Need: Extravagance and Shortages in America's Military''.] Zenith Imprint, 2007. ISBN −076032-869-2.
* Veronico, Nick and Jim Dunn. ''21st Century U.S. Air Power''. St. Paul, Minnesota: Zenith Imprint, 2004. {{ISBN|0-7603-2014-4}}.
{{Refend}}

==External links==
{{Commons}}
* [https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104492/c-5-abc-galaxy-c-5m-super-galaxy/ C-5 A/B/C Galaxy and C-5M Super Galaxy U.S. Air Force fact sheet]
* [http://www.lockheedmartin.com/us/products/c5.html C-5M page on LockheedMartin.com]
* [http://www.ingentaconnect.com/content/asma/asem/2006/00000077/00000009/art00012 "Fatigue and Related Human Factors in the Near Crash of a Large Military Aircraft"]. ''[[Aviation, Space, and Environmental Medicine]]'', Volume 77, Number 9, September 2006, pp.&nbsp;963–970.
* [https://www.youtube.com/watch?v=RadGavdgKAk C5 wing vortex study] (NASA video) <!--more at https://www.youtube.com/user/DrydenTV/videos -->

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{{US transport aircraft}}
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[[Category:Lockheed aircraft|C-005 Galaxy]]
[[Category:1960s United States military transport aircraft]]
[[Category:Quadjets]]
[[Category:High-wing aircraft]]
[[Category:T-tail aircraft]]
[[Category:Aircraft first flown in 1968]]
[[Category:Aircraft with retractable tricycle landing gear]]