MiG-21 Series

Without a doubt, the MiG-21 is one of the most famous military aircraft in the world. Its name is known by specialists and the general public alike. Few of its competitors share the same level of name recognition: the Spitfire in Great Britain, the Mirage in France, and the Flying Fortress in the United States —that is about all. The MiG-21 owes its fame to many reasons. Even in World War II no other aircraft has had as many versions (more than thirty) No other aircraft has been operat­ed by as many countries (forty-nine). And no other aircraft has found itself involved in as many armed conflicts.

Fifteen primary versions of the MiG-21 were mass-produced for twenty-eight years (from 1959 to 1987) in three factories in the USSR. The aircraft was also built under license in Czechoslovakia, China, and India. No fewer than seventeen world records were set by several spe­cial versions (the Ye-33, Ye-66, Ye-66A, Ye-66B, and Ye-76). As is the case for any aircraft whose family has developed over several decades, the combat effectiveness of the MiG-21 improved over time thanks to the technical progress made in three basic fields:

1 Improvement of the thrust-to-weight ratio for better performance

— static thrust of the turbojet went up by over 40 percent: from 5,000 daN (5,100 kg st) to 6,960 daN (7,100 kg st)

— maximum speed at sea level increased from 1,220 km/h (659 kt) to more than 1,300 km/b (700 kt)

— initial rate of climb jumped from 130 meters per second (25,600 feet per minute) to 225 meters per second (44,300 feet per minute)

— acceleration time from 600 km/h (324 kt) to 1,100 km/h (594 kt) at sea level decreased from 28 to 19.3 seconds

— maximum operating limit load factor increased from 7 to 8.5

— maximum operating indicated airspeed (IAS) was raised from 1,200 km/h (648 kt) to 1,300 km/h (702 kt)

— maximum authorized hedge-hopping time at 1,000 km/h (540 kt) increased from 28 to 36 minutes

2. Reinforcement of the weapon system

— the number of loading options expanded from twenty to sixty – eight because of the addition of multipurpose hard points

— the minimum distance at which a flying target could be destroyed closed from 1,000 m (3,280 feet) to 200 m (655 feet) thanks to the installation of built-in cannons

3. Growth of the aircraft’s safety of flight and operational availability

— flight time per accident was stretched from 3,000 to 39,600 hours

— the aircraft’s lifetime was brought up to 2,100 hours

— mission preparation time was reduced by 30 to 40 percent

When in 1954 all of the OKB’s efforts were focused on the concep­tion of a modern fighter capable of flying at twice the speed of sound or faster, its engineers had no preconceived ideas of which aerodynamic strategy to select. Sweepback wing? Delta wing? Both shapes had their proponents. Whatever the chosen approach, all of the specialists knew full well that their research would have to go off in hundreds of direc­tions whether aerodynamics, power plants, or systems were con­cerned. The main problem was obviously to make the right choice for the aerodynamic design formula. This is why several experimental pro­grams were launched simultaneously in two quite distinct directions: the sweepback-winged Ye-2 and Ye-2A and the delta-winged Ye-4, Ye-5, and Ye-6.

Everyone knows that the latter formula prevailed in the end. But it should be noted that the victor was in fact a tailed delta configuration.

The sweepback wing was tested on this Ye-2 airframe, but the MiG-21 silhouette was already taking shape

MiG has always maintained that only this well-balanced scheme could (unlike the French Mirage III) secure a satisfactory degree of maneu­verability at low speeds due to a high lift coefficient in this sector of the flight envelope. The OKB also decided to use the axial flow turbojet and the variable geometry air intake (with a multiposition cone) that helped to recover the engine inlet pressure over a wide range of angles of attack (AOA) and at supersonic speeds. Other criteria included sim­plicity of manufacture and ease of maintenance; in short, it was meant to be a trouble-free aircraft for maintenance personnel, the field sup­port crew, and the pilots. Here begins the long story of the MiG-21.