Kapila Jayampathy joined Sri Lanka Air Force on 5 March 1982 as an Officer cadet and was commissioned as a Pilot officer in General Duties branch of No. 4 Squadron SLAF in 1985.

In December 2009, he took over duties as the Base Commander Sri Lanka Air Force Base China Bay.

Later, when SLAF Base China Bay was upgraded and renamed as the Air Force Academy, he was re-designated as the Commandant of the Air Force Academy.