After a competitive fly-off between prototypes of the Northrop P530 and General Dynamics 401, as the YF-17 and YF-16 respectively, the latter was adopted by the USAF and emerged victorious in the fighter "sale of the century" when it was chosen as the F-104 replacement by four European nations.
Разработка CL-1200 и обнародование его были осуществлены в 1971 году. Lancer в сравнении с F-104 должен был обладать лучшими характеристиками. Макет затем покрасили в белый цвет - он изображал уже X-27. Lockheed, Northrop and General Dynamics were among the companies that responded, in 1971, to the US Department of Defense request for proposals for the development of a lightweight fighter (LWF). The Lockheed proposal, based on the F-104 Starfighter, was the CL-1200 Lancer, to which the designation X-27 was later applied.