SOURCE: IDRW According to report by defensenews.com , around 2o Indiaâ€™s Front line Sukhoi 30 mki fighters have been grounded due to F Avionics Gears which includes head-up display and the mission computer .In the letter dated 28 February, a top HAL functionary has stated that the head-up displays and other displays were â€œblanking offâ€ during flight of the aircraft belonging to some particular batches of the Su-30MKI, Cockpit displays of some of the Su-30MKI â€œblanking offâ€ affected the use of the aircraft, India has already has informed Russia, which is the manufacturer and supplier of these fighter planes to IAF. Another media report had said that nearly 50 % of sukhoi fleet is suffering from this problem but the latest report indicates that only certain batches are showing up this problems .While a Russian Diplomat has said that they are not sure which subsystems is causing problems , subsystems are either supplied by Irkut or by HAL . The documents related to communication between Indian and Russian officials have come to light after hackers breached Russian defence firmsâ€™ networks and posted the material online. shortage of Supply of spares for Sukhoi 30 has been on going issue for years now , While IAF and HAL blames Russia for delays in supply of spares and Russia blames HAL and IAF for not keeping long term inventory and repeatedly placing short orders which takes more time to fulfill . Supply of tyres for Sukhoi 30 was one of the major issue affecting the fleet for few years now and recently Indian Tyre manufacturer MRF was pulled in by Indian air force to design and supply Indian made tyres for Sukhoi 30 , MRF has successfully designed and made tyres fit for Sukhoi 30â€²s , but Russians other other side have protested such move by India . Interestingly reports also says that HAL made Sukhoi 30 are 30 % more expensive then a Russian made Sukhoi 30 , local production has not lead to cheaper aircraft , even though India has cheaper labour , supply of spares to HAL by Local Private Suppliers are not cheap which is leading to higher price tag which HAL has not been able to bring down even after so many years .