Dassault designed the Mirage F1 as a private venture, using its own funds, as a successor to its Mirage III and Mirage 5 fighters, with the F1 being a smaller version of the Mirage F2 being developed for the French Air Force. It was of similar size to the delta-winged Mirage III and V, and was powered by a SNECMA Atar 9K turbojet as used in the Dassault Mirage IV, but unlike its predecessors, it shared the layout of a swept wing mounted high on the fuselage and a conventional tail surface as used by the F2. Although it has a smaller wingspan than the Mirage III, the F1 nevertheless proved to be superior to its predecessor. It can carry up to 43% more fuel, has a shorter take-off run and better maneuverability.The first prototype made its maiden flight on 23 December 1966. Despite the prototype crashing on 18 May 1967 due to flutter, killing its pilot, an order for three prototypes was placed on 26 May 1967, the larger and more expensive F2 being abandoned.