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 HALs 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.
Back
to Top
Disclaimer
Copyright
|