From the IAF Vault: Evolution of the MiG-21 in the Indian Air Force

The MiG-21 and the innumerable variants in the Indian Air Force's long service history have consistently been a conundrum for enthusiasts. IAF historian Anchit Gupta gives a lowdown on evolution of the MiG-21 types in IAF service.

The MiG-21F-13 Type-74 Fishbed-C was the first in the IAF. Six of these were acquired in March 1963 and served till 1968. F or Forsirovannyy ('Uprated') and 13 denotes the K-13 Air-to-Air Missiles it carried. They carried the serial numbers BC-816 to BC-821. 

Powered by the R-11 engine, the pitot tube was below the engine intake, unlike subsequent types, where it was on top. The armament was the K-13 missile and one 30mm cannon. Designed for intercepts, its short endurance, lack of radar and poor single shot kill probability was a problem.

In March 1965, the IAF got the PF variant -- Perekhvatchik ("Interceptor"), F = Forsirovannyy ("Uprated") -- Type 76, Fishbed D. Six of these were acquired with serial numbers from BC-822 to BC-827. It had an R-11F2-300 engine for better endurance and a first-ever R1L Search Radar.

These changes came with a flaw -- it had to give up its cannons and rely only on missiles. Blooded during the 1965 war, the lack of a cannon would bite. Read this story of a missed Sabre kill HERE

A few T-76s were upgraded with an R2L radar and an R-11F2S-300 engine. This was to bring them in line with the T-77 that was to become the main variant in service. The aircraft kept their original serials, but the prefix 'BC' was changed to 'C'. The 28 and 29 Squadrons were the only ones to operate the T-74 and the T-76.

The lack of an integral cannon was in sync with the gun versus missile debate of the times. The variants of the F-4 indicate progress. Suffice it to say that the gun continues to feature in all modern fighter aircraft.

In 1966, the IAF took the first big step when it contracted for the MiG-21 FL, Type -77 variant -- FL denoting forsazh-lokator meaning afterburner and radar. A totoal of 38 aircraft manufactured in the USSR and another 197 were manufactured by the Hindustan Aeronautics Limited between 1966-73. 

The Type 77 aircraft improved on the Type 76 aircraft. It had a new Radar-to-Lidar, Identification friend or foe antenna, radar warning and larger fuel capacity. It also had an attachable gun pack GP-9, consisting of a twin barrel 23 mm GSh gun on the centre point. The Type-77 aircraft was the first usable variant for IAF and boy, did the IAF use it!

The Type 77 aircraft had a pitot tube dead centre, a big antenna on the dorsal spine and a spine thinned off in the middle to tail. Early examples carried the fuselage roundel aft of the wing - on the rear fuselage. Later it was moved to the front fuselage just below the cockpit. 

The Type-77 aircraft also heralded the era of using the MiG-21 for the air-to-ground role; 500 kg bombs were delivered at the Tilpat range in 1967. For the bombing role in the 1971 war, they earned the nickname 'runway busters'.

The canopy of variants up until the Type-77 aircraft opened on a hinge on the front of the canopy. When ejecting, the seat connected with the canopy made a capsule to enclose the pilot and protect him from the airflow, after which it would separate, and the pilot would parachute down. 

The Type-77 aircraft initially had two hardpoints under the wing for AAMs and one centerline for the drop tank/GP-9 gun pod. Sometime in the 1980s, it was modified to have four wing hardpoints for AAMs/Bombs. This greatly enhanced usability. 

The Type-77 would serve the IAF for 47 years across 11 combat squadrons, the longest of any variants, ruling the eastern skies and was extensively used in training post-1986. It was also the first instance of mass production by the Bengaluru-based HAL.

High-altitude combats were rare, and mid or low-altitude capability was critical. The MiG-21M/MF (Modernizirovannyy or Modernised, Forsirovannyy or Uprated) Type-96 Fishbed-J was the IAF’s latest addition in 1973. Some of these fighter aircraft were directly purchased, and the rest of them HAL manufactured. In all, 198 MiG-21M/MF fighter jets were manufactured.

A total of 36 aircraft made in the USSR came with the R-13 engine and had a built-in GSh-23L cannon instead of a cannon pod, freeing up the centre pylon for a drop tank. However, the HAL-manufactured T-96s had the modified R-11 (from the T-77). Overall, it offered more fuel, better performance and avionics.

The Type-96 aircraft was also called Type-88 in HAL terminology. It had a zero-speed, zero-altitude ejection seat (the old capsule canopy was gone), gyroscopic gunsight and four-wing pylons that could carry drop tanks (with a better engine). It would serve over 45 years and also be used in the fighter-recce/electronic warfare role.

Visually the T-96 aircraft had a sideways opening clamshell canopy and the pitot tube (which measures fluid flow velocity) on the right side of the nose. The dorsal spine had a short distinct line at the base of the tail and the drop tanks on the wing pylons. The angle of attack vane on the left side of the nose was another visual indicator though it was later retrofitted to the T77 as well.

A saddle tank spoilt the beautiful area ruling and the T-96 aircraft could not match the supersonic perfection of T-77. In 2001, the HAL-manufactured T-96 were retrofitted with R-13 engines (from Romania), significantly improving their life cycle and efficiency, and enabling the T-96 to continue with type training for longer.

In 1975, the IAF acquired the MiG-21BIS, Type -75 and Fishbed-N variants. The key improvement was the R-25 engine, better avionics, gun-sight and blind flying instrumentation. The 70 aircraft were acquired in flyaway condition, and 220 were produced by HAL between 1978-1985. 

Visually, the T-96 aircraft was different from a Type-75 aircraft owing to a fatter spine ending further aft of the T-75. A subtle difference between the BIS and the Type-96 aircraft is the larger air intake lip on the former, which is slightly more tapered in the latter. 

Lastly, in 2001, the IAF upgraded the BIS to Bison (not a new aircraft purchase) for Beyond Visual Range missiles, KAB-500 TV guided bombs, Electronic Counter Measures, Radar Warning Receiver, cleaner and larger view cockpit and Helmet Mounted Sighting System. The aircraft carried the serial number 'CU' in place of 'C'.

The difference between the Bison and the T-75 variants visually included bulged canopy and a single-piece windshield, no vanes on the pitot, Radar Warning Receiver and ILS antennae on the vertical fin, grey radome versus green on all previous variants, and wing root fairings for CMDS (which holds automatic chaff and flare dispensers) and avionics. 

Every fleet needs a trainer. The MiG-21U/UM/US Mongol (Type 66-400 /66-600/ 68 / 69) is a two-seat trainer version with cockpits arranged in tandem. Over 100 aircraft were acquired from the USSR and Eastern European countries; none were manufactured by HAL. 

The trainer has larger main wheels and no cannon armament. It has broader-chord vertical tail surfaces, a deeper dorsal spine, and no dorsal fin fillet. It also sports an IAF roundel both at the fore and aft of the wing. 

With nearly 850 aircraft operated by the IAF across 4.5 generations and a multitude of variants, you are not alone in being confused with the variants. The image above is a simple guide to visually identify the type when you see an Indian Fishbed!