He was appointed Chief of the Defence Staff in 2009 in an acting capacity which was confirmed in 2012 and he step down 2013, retiring from the Air Force.

He was restored to active service in 2019, when he became the first to be appointed to the rank of Marshal of the Sri Lanka Air Force.

Goonatilake completed his education at St Peter's College, Colombo, where he excelled in both studies and sports.

He followed his father by joining the Sri Lanka Air Force as an Officer Cadet in the General Duties Pilot Branch on 13 January 1978.

On successful completion of flying training, he was commissioned in the rank of Pilot Officer on 24 August 1979.

[5][6] He was appointed Chairman Board of Management of Civil Aviation Authority of Sri Lanka (CAA of SL) with effect from 5 October 2009 until relinquishing duties on 28 December 2011.

Rehan, followed the family tradition of joining the Sri Lanka Air Force as a pilot.

Goonetileke was admitted to the Degree of Doctor of Philosophy (Honoris Causa) by the University of Kelaniya on 20 November 2009, in recognition of his professional achievements as the Commander of the Air Force.