The Indian Air Force's (IAF's) Su-30MKI multirole fighter fleet is plagued by frequent "engine failure-in-air and engine-related problems" and poor operational serviceability, Defence Minister Manohar Parrikar told parliament on 17 March.


Five twin-engine Su-30MKIs have crashed since the platform began to enter service in 1997.


Parrikar said between January 2013 and December 2014 the IAF had recorded technical problems with 35 Saturn AL-31FP engines that power the licence-built Su-30MKIs. The problems were related to faulty bearings and low-pressure oil.


He said metal fatigue caused these bearings, which are incorporated to reduce friction between the fighter's moving parts, to chip or fragment and the resulting particles contaminated the oil flow.


Of 69 Su-30MKI engine failures investigated since 2012, the minister said "33 were due to finding [metal] chips in the oil, 11 due to vibration in the engine, and 8 because of low pressure of lubricating oil".


He did not provide any explanation for the remaining 17 engine-related problems, but Parrikar said that the engine's original equipment manufacturer (OEM) had "offered nine modifications or technological improvements in the production of new aero-engines and during overhaul of engines".


These included "better lubrication, better fitment of bearings, and better quality of oil".


All these measures, the minister stated, had been incorporated into 25 AL-31FP engines that Hindustan Aeronautics Limited (HAL) had since licence-built at its Koraput plant in eastern India.


As a result, engine maintenance and overhaul, which had been taking place after 500 flying hours, now took place after 900 hours.


The IAF operates 200 Su-30MKIs, but of these only 110 or 55% were operationally available due to poor serviceability, Parrikar said, adding that this would increase to 70% by the end of 2015.


Parrikar also said that efforts were afoot to secure the return of around 10 of 40 IAF Antonov An-32 military transporters that are stranded in Ukraine where they were undergoing an upgrade. Around 30 An-32s, which were upgraded to An-32RE levels in Ukraine under an INR19.67 billion (USD313.3 million) agreement inked in 2009, had returned home by 2014.
The upgrade, aimed at increasing the An-32's operational lifespan from 25 to 40 years, includes advanced avionics, cockpit layout modifications, noise and vibration reductions, and improving serviceability.
The IAF's Base Repair Depot at Kanpur in northern India has been similarly retrofitting a further 65 An-32s.


Meanwhile, Parrikar said that the long awaited decision on the IAF acquiring 126 Dassault Rafale fighters could not be "endless" and would be expedited.


He said that the Contract Negotiation Committee, which has been negotiating with Dassault over the purchase since January 2012, is expected to submit its report in March, following which a "final decision" will be taken on the deal.


Indian foreign secretary S Jaishankar is visiting Paris later this month to finalise details of Prime Minister Narendra Modi's visit in April. The Rafale deal is likely to feature prominently in talks with the French government.