the MiG-19. The second had a stepped arrangement with one engine amidships, with exhaust under the fuselage, and another in the aft fuselage. The third project had an engine arrangement similar to that of the English Electric Lightning, with two engines stacked vertically. Option two and three were both rejected because the size of the engines meant any of them would result in a very tall aircraft which would complicate maintenance.6
The idea of placing the engines in underwing nacelles was also rejected because of the dangers of any thrust asymmetry during flight. Having decided on engine configuration, there was thought of giving the machine variable-sweep wings and a second crew member, a navigator. Variable geometry would improve maneuverability at subsonic speed, but at the cost of decreased fuel tank capacity. Because the reconnaissance aircraft would operate at high speed and high altitude the idea was soon dropped. Another interesting but impractical idea was to improve the field performance using two RD36-35 lift-jets. Vertical takeoff and landing would allow for use of damaged runways during wartime and was studied on both sides of the Iron Curtain. The problem has always been that engines dedicated to vertical lift do not contribute with any power in horizontal flight, and occupy space in the airframe needed for fuel. The MiG interceptor would need all the fuel it could get, so the idea was abandoned.8
The first prototype was a reconnaissance variant, designated "Ye-155-R1", that made its first flight on 6 March 1964.9 It had some characteristics that were unique to that prototype, and some of these were visually very evident: the wings had fixed wingtip tanks (600 litre capacity) to which small winglets were attached for stability purposes, but when it was found fuel sloshing around in the tanks caused vibrations they were eliminated. The aircraft also had attachments for movable foreplanes, canards, to help with pitch control at high speed (provisions for canards had previously been installed, but not used, on the Ye-152P.)810
The first flight of the interceptor prototype, "Ye-155-P1", took place on 9 September 1964.11 Development of the MiG-25, which represented a major step forward in Soviet aerodynamics, engineering and metallurgy, took several more years to complete.1112
The Mikoyan-Gurevich design bureau soon realized that the performance of the new aircraft gave it great potential to set new flight records. In addition to their normal duties, the prototypes Ye-155-P1, Ye-155-R1, Ye-155-R3 were made lighter by removing some unneeded equipment, and were used for these attempts. Under Federation Aeronautique Internationale (FAI) classification the Ye-155 type belonged to class C1 (III), which specifies jet-powered land planes with unlimited maximum take-off weight. Records set included:
- The first claim was for world speed records with no payload and payloads of 1,000 and 2,000 kilograms. Test pilot Alexander Fedotov reached an average speed of 2,319.12 km/h over a 1,000 km circuit in 16 March 1965.11
- For pure speed, with no payload, test pilot Mikhail M. Komarov averaged 2,981.5 km/h over a 500 km closed circuit on 5 October 1967.11 On the same day A. Fedotov reached an altitude of 29,977 metres (98,350 ft) with a 1,000 kilogram payload.14 The MiG eventually became the first aircraft to go higher than 35,000 metres (115,000 ft).14
- Time to height records were recorded on 4 June 1973 when Boris A. Orlov climbed to 20,000 m in 2 min 49.8 sec. The same day, Pyotr M. Ostapenko reached 25,000 m in 3 min 12.6 sec and 30,000 m in 4 min 3.86 sec.14
- On 25 July 1973, A. Fedotov reached 35,230m with 1,000 kg payload, and 36,240 m with no load (an absolute world record).14 In the thin air, the engines flamed out and the aircraft coasted on in a ballistic trajectory by inertia alone. At the apex the speed had dropped to 75 km/h.
- A few years later, on 31 August 1977, "Ye-266M" flown by MiG OKB Chief Test Pilot Alexander V. Fedotov, set the recognized absolute altitude record for a jet aircraft under its own po