In this undated picture released 25 February 2004, A pair of Indian SU-30 fighter aircraft lead a pair of  USAF F-15C fighter aircraft as they fly over India, during the Indo-US joint air exercise "Cope India -04" . The ten day long exercise started in Gwalior 16 February, with the aim of enhancing mutual understanding and ensuring the future cooperation between the two air forces.  AFP PHOTO/HO (Photo credit should read US DEPARTMENT OF DEFENCE/AFP/Getty Images)