The Indian air force has thrown doubt on whether it will accept its latest batch of multirole Sukhoi Su-30MKI fighters from Russia, as continued engine failures plague the availability of the aircraft, writes Shyam Ravindran.

The air force says it will not accept the new batch until the Russian manufacturer Irkutsk Aviation Production Association (IAPO) corrects the problems.

IAPO has already flown a batch of Su-30MKIs to the Lohegaon air base in Pune, India, but the air force has directed the Ministry of Defence to stall the payment until theservice's demands are met.

The $2.2 billion Su-30MKI deal calls for delivery of 120 aircraft from Russia and licensed manufacturing of another 140 by India's Hindustan Aeronautics. Under the arrangement, Russia's IAPO will supply the plant assembly line machinery and instrument systems for the production of the aircraft.

Defence ministry officials confirm that the NPOSaturn AL-31FP engines powering the Su-30s started to have problems soon after their induction inthe fleet due to some fundamental faults in the engine. Each engine is supplied with a 300h time between overhauls (TBO). However, a high rate of engine failure was noted in a number of Su-30s by the air force even before the TBO was reached.

In September, 18 Su-30s procured from Russia in 1997-8 were grounded as a result of engine faults. The Indian defence ministry approached IAPO to rectify the problem but IAPO claimed its contract did not cover engine failures. The air force relies on the SU- 30MKI fleet for nuclear-weapons delivery, using mid-air refuelling to achieve the necessary range. Other features of the fighter include thrust vectoring nozzles that can provide additional manoeuvrability.

Source: Flight International