Personnel from California Air National Guards 144th Fighter Wing and the Ukrainian Air Force pose for the camera at the opening ceremony of Exercise Clear Sky on October 8, 2018.

Su-27P 56 blue takes off from Starokostiantyniv. This aircraft previously served with the 831st Tactical Aviation Brigade at Mirgorod, but was transferred to Ozernoye to serve in the newly formed 39th ISqTA in 2015.

Su-27PM1 58 blue takes off from Starokostiantyniv Air Base.

Loaded with CATM-9M, CATM-120D training missiles and Cubic ACMI pods, Californian Air National Guard F-15C 84-0004 seen departing Starokostiantyniv on a dissimilar air combat training mission against Ukrainian Su-27s and MiG-29s on October 12, 2018.

American pilots show a Ukrainian pilot the cockpit of an F-15C.

Painted in commemorative colours to celebrate the 75th anniversary of California Air National Guard’s 194th Fighter Squadron, F-15C 84-0004 deployed to Ukraine to take part in Exercise Clear Sky 2018.

Su-27UBM1 70 blue at Starokostiantyniv just days before its loss on October 9, 2018.

Su-27UBM1 70 blue performs flypast at Starokostiantyniv during the opening ceremony of Exercise Clear Sky 2018.

A Ukrainian Air Force crew chief directs an Su-27.