New Delhi, The Indian Air Force (IAF) is set to retire a squadron of MiG-21 Bison aircraft by September 30. Thereafter, only three squadrons of the aircraft will remain in service, which would be phased out by 2025.

"The 51 Squadron based out of Srinagar airport is being number plated on September 30... Thereafter, every year one squadron will be fitted with a number plate," sources said.

The 51 Squadron is famous for thwarting Pakistan's air strike on India on February 27, 2019 and shooting down an F-16 by an aircraft flown by Wing Commander (now Group Captain) Abhinandan Varthaman.

Sources said this is the only instance when a MiG-21 aircraft shot down an F-16 in an air-to-air combat.

IAF is replacing MiG-21 fighter jets with more capable aircraft like Su-30 and indigenous Light Combat Aircraft (LCA).

In the last 20 months, 6 MiG-21 aircraft have crashed in accidents in which five pilots have lost their lives. On Thursday evening, a MiG-21 Type 69 Trainer aircraft crashed in Barmer, Rajasthan killing both the pilots.

The MiG-21 was supposed to be discontinued long back, but the delay in induction of the LCA Tejas aircraft has forced the IAF to continue flying these aircraft.

As per officials, the IAF conducts extensive checks of these aircraft before flight and all safety aspects are taken care of before the pilot takes off.

Officials said that the number plated squadron would be reactivated soon with more capable aircraft in the near future.