Saudi state-run news agency SPA said the king has instructed relevant authorities to replace Tamimi who has held the position since June 2017.
His replacement is yet to be announced.
Tamimi, a pilot by profession, was the first national helicopter commander at Aramco’s Arab Helicopter Company, Gulf Business reports.
The outgoing GACA boss also established the first Saudi company specializing in aerial photography and surveillance. He served as CEO of the Gulf Aviation Technology Company from 2008 to 2015.