Under the ongoing joint air exercise in Japan an Indian Air Force pilot flew in a F2 Viper and a Japanese pilot flew on the Indian su-30 and the swapping of Pilots was done to get the experience of the fighter jets that is flown by the two countries.
The Japan air self-defence force is observing the performance of the Su-30 and is learning BVR tactics that are being deployed by the Indian Pilots.
The Japan air self-defence force has also deployed its F-15j fighter jet which is often considered a direct rival to the Su-30 aircraft.