Dassault Mirage IIIV The Dassault Mirage IIIV was a French vertical take - off and landing ( VTOL ) prototype fighter aircraft of the mid - 1960s . The Mirage IIIV model followed the Dassault Mirage III and featured eight small vertical lift jet s straddling the main engine . The design was in response to a NATO specification for a VTOL strike fighter . One of the two aircraft built was destroyed in an accident and the project was abandoned ; the surviving aircraft is on public display . Design and development . Four designs were submitted , the Mirage IIIV design , the Fokker - Republic D . 24 " Alliance " , the BAC 584 and the Hawker P . 1154 , to NATO in January 1962 in competition for the AC / 169 specification for a supersonic V / STOL strike fighter to meet NATO Basic Military Requirement 3 . In May that year the resulting judgement that the P . 1154 was the technically superior , but when considering as well the financing and work - sharing opportunities the Mirage IIIV was judged its equal in merit . NATO was not in the position to fund the full development of either winner leaving it up to the individual member countries . Dassault Balzac V . Since the Rolls - Royce RB162 lift engines specified for the Mirage IIIV were not expected to be available before 1963 , Dassault modified the first Mirage III prototype as the Balzac V to serve as an interim VTOL testbed . Fitted with eight Rolls - Royce RB . 108 lift engines and an unreheated Bristol Orpheus BOr 3 as the main engine . The Balzac began tethered hovering on 12 October 1962 and achieved the first free hover only six days later . The first accelerating transition from vertical take - off to horizontal flight took place on its 17th sortie on March 18 , 1963 . The aircraft had two fatal accidents , one in January 1964 and one in September 1965 . After the last accident the aircraft was not repaired . Mirage IIIV . In the meantime , the Balzac had led to the actual Mirage IIIV , which was twice as big . Two prototypes were built . The first Mirage IIIV performed its first hovering trial on 12 February 1965 . The IIIV had the general layout of earlier Mirage fighters , but it was longer and had a bigger wing , and , like the Balzac , nine engines : a single SNECMA - modified Pratt & Whitney JTF10 turbofan , designated TF104 , with thrust of 61 . 8 kN ( 13 , 900 lb ) , and eight Rolls - Royce RB162 - 1 engines , each with thrust of 15 . 7 kN ( 3 , 525 lbf ) , mounted vertically in pairs around the centreline . The TF104 was originally evaluated on a special - built trials machine , the " Mirage IIIT " , which was much like a Mirage IIIC except for the change in engine fit . The TF104 engine was quickly replaced by an upgraded TF106 engine , with thrust of 74 . 5 kN ( 16 , 750 lb ) , before the first prototype made its initial transition to forward flight in March 1966 . It later attained Mach 1 . 32 in test flights . The second prototype featured a TF306 turbofan for forward thrust of 82 . 4 kN ( 18 , 500 lb ) , and first flew in June 1966 . In September of that year , it attained Mach 2 . 04 in level flight , but was lost in an accident on 28 November 1966 . The Mirage IIIV was never able to take off vertically and successfully go supersonic in the same flight . The loss of the second prototype effectively killed the program , and in fact killed any prospect of an operational Mach 2 vertical take - off fighter for decades . The British Hawker P . 1154 had been cancelled in 1965 by the government just as the prototypes were being built , though its subsonic brother , the Hawker - Siddeley Kestrel VTOL attack aircraft was flying in tri - partite trials with the UK , US and West Germany . The French preferred the Mirage IIIV , and the international cooperation needed to make the P . 1154 a reality never materialized . Some of the P . 1154 work contributed to the final operational vertical take - off fighter based on the Kestrel , the highly successful Harrier . The Mirage IIIV was never a realistic combat aircraft . The eight lift engines would likely have been a maintenance nightmare , and certainly their weight imposed a severe range and payload penalty on the aircraft . The cockpit and ancillary electronics of the Mirage IIIV were re - used in the Mirage IIIF , later Mirage F1 .