Mikoyan-Gurevich I-7

The Mikoyan-Gurevich I-7 was a development of the Mikoyan-Gurevich I-3 experimental fighter. Planned as a Mach 2-class aircraft, the I-7 was the second of a series of three experimental fighter aircraft from the Mikoyan-Gurevich design Bureau. Like the Mikoyan-Gurevich I-3, the I-7 was to be one of the components of the automated Uragan-1 then under development by protivovozdushnaya oborona strany (PVO Strany) (English transition: Anti-Air Defence of the Nation), the Soviet defense system.

The Uragan (Hurricane) defense system was similar to the American Semi-Automatic Ground Environment (SAGE) system. Both systems used ground acquisition and tracking radar data that was fed into a computer control center that remotely guided the interceptor aircraft (or missiles) up to and including weapon final aim and/or weapon release, and then in the case of an aircraft, return the aircraft back to base and landing. A pilot was on board the remotely controlled interceptor, but was there only as a backup in case of failure in the remote control system.

In the mid/late 1950s the PVO sent requirements to many of the aircraft design bureaus for an aircraft suitable for the Uragan systems. Several of the bureaus, including Mikoyan-Gurevich, developed a series of aircraft proposals to meet those requirements. MiG’s proposal was the I-3, which evolved into the I-7 and finally the I-75 experimental aircraft.

The I-3 was to use the Klimov VK-3 afterburning bypass turbojet, the first soviet-designed afterburning bypass engine. The technically advanced VK-3 engine was not found reliable and did not meet the required power, and its troublesome development ended with cancellation of the project.

The sole I-3 aircraft was rebuilt with the more reliable Lyulka AL-7E/F afterburning turbojet engine, a project that required considerable modifications to the fuselage, as the new engine was larger. The reworked airframe was quite different from the I-3, and was designated as the I-7.

The I-7 was later involved in a landing accident and became the Mikoyan-Gurevich I-75 when the airframe was modified to accept the more powerful Lyulka AL-7F-1 engine.