An IDC Analysis


New Delhi, 15 May 2002


In the last decade the IAF has been bugged with a plethora of air accidents and the figure of 239 crashes has been floated in the media and out of these the major casualty has been the MiG 21 series. Over 100 MiG 21 aicraft have gone down and have taken over 38 lives –– the lives of pilots trained at great cost and of great value to the nation.

There have been many reasons for the accidents. The landing speed of the MiG 21 is the highest in the world and at 320 knots it is fatal if the pilot makes the slightest mistake while landing. The former Chief of Air Staff ACM A Y Tippnis went for a sortie and had to abort his first landing and there was panic in the control tower. Being a MiG veteran though, he landed the aircraft safely.

The MiG 21 aircraft design is old and the earlier versions –– MiG 21 Type 75 is a truly obsolete machine and only skilled operators can cope with an emergency on this machine.

The engines of the earlier MiG 21s are the R-11, which are of 1960's vintage. Since then however, the engine and compressor systems have progressed immensely. Today the MiGs are powered by the HAL Koraput manufactured R25 engines.

When there is a flame out i.e. engine failure –– due to a fuel line problem or drop in pump pressure or such other problem that the pilot begins to loose height very fast and in the panic of restarting the engine, it can happen that the compressor gets an uneven fuel-air mixture, leading to a small explosion or over exertion on the compressor blades.

Combined with this problem has been the inadequate training of pilots to transit from the Iskara and IJT trainers to the fast supersonic MiG 21. Therefore, reports by ACM La Fontaine and Dr. A. P. J. Abdul Kalam in the past had cited pilot error, mechanical failure and bird hits as the problem areas and the Air Force has not been able to lick them. It is good that ACM S. Krishnaswamy has grounded the Type 75, which may even have to be phased out.

More recently the media had cast doubts over the efficacy of the R25 engine manufactured by HAL’s Koraput Division, which powers the MiG 21 BIS multi-role fighter aircraft. The engine is a twin spool, axial flow, turbojet engine incorporating an after-burner system and variable area jet nozzle. The engine has provision for an emergency after burner thrust boost, which can be selected below 4.5 km altitude. The media reports suggested that substandard spares were used to overhaul the engines, which resulted in their failure.

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