Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Passage: A cikin 1963, Sojojin Sama na Amurka sun fara jerin ayyukan bincike kan babban jirgin sama mai jigilar kayayyaki. Kodayake an gabatar da C-141 Starlifter, jami'ai sun yi imanin cewa ana buƙatar jirgin sama mafi girma da ƙwarewa, musamman don ɗaukar kaya wanda ba zai dace da kowane jirgin sama na yanzu ba. Wadannan nazarin sun haifar da bukatun farko na CX-Heavy Logistics System (CX-HLS) a watan Maris na 1964 don jirgin sama mai nauyin nauyin 180,000 fam (81,600 kg) da gudun Mach 0.75 (500 mph ko 800 km / h), da kuma ba tare da tanadi ba 5,000 nautical mil (9,300 km) tare da nauyin 115,000 fam (52,200 kg). Dole ne sararin jigilar kaya ya zama 17 feet (5.18 m) mai faɗi da 13.5 feet (4.11 m) mai tsayi da 100 feet (30 m) mai tsayi tare da samun dama ta ƙofofi a gaba da baya. Burin adana yawan injina zuwa huɗu ya buƙaci sabbin ƙirar injin tare da haɓaka ƙarfin da ingantaccen tattalin arzikin mai. A watan Mayun 1964, shawarwarin jirgin sama sun zo daga Boeing, Douglas, General Dynamics, Lockheed, da Martin Marietta; An gabatar da shawarwarin injiniya daga General Electric, Curtiss-Wright, da Pratt & Whitney. An ba Boeing, Douglas, da Lockheed ƙarin kwangilar binciken don jirgin sama, tare da General Electric da Pratt & Whitney don injuna. Abubuwan da aka gabatar na jirgin sama sun raba abubuwa da yawa. Kamar yadda CX-HLS ya buƙaci a iya ɗorawa daga gaba, dole ne a haɗa ƙofa a inda akwatin jirgin yake yawanci. Dukkanin kamfanonin sun magance wannan matsalar ta hanyar matsar da matukin jirgi sama da yankin kaya; Douglas yana da karamin "kwaskwarima" gaba da sama da reshe, Lockheed yayi amfani da "kwaskwarima" mai tsayi wanda ke gudana tsawon jirgin sama tare da reshen reshen yana wucewa ta ciki, yayin da Boeing ya haɗu da su biyun, tare da tsayi mai tsayi wanda ya gudana daga bayan hanci zuwa bayan reshen. A cikin 1965, an zaɓi ƙirar jirgin sama na Lockheed da ƙirar injin General Electric don sabon jigilar C-5 Galaxy, wanda shine mafi girman jirgin saman soja a duniya a lokacin. Ƙofar ƙofar da ƙuƙwalwar ƙuƙwalwar ƙuƙwalwar ƙuƙwalwa za a ɗauka zuwa...  Tambaya: Wanene zai yi nazarin jirgin sama?
Boeing, Douglas, da kuma Lockheed