What was found
AIRCRAFT RETURNED TO PLATFORM DUE TO DUCT PRESS LOW INDICATION IN THE LT ENG, SHOWING 5 PSI. PERFORMED REVISION IAW 36-11-00, DETECTING A PNEUMATIC LEAK IN THE LT ENG PRSOV, DEFERRED IAW MEL 36-5-1 CAT C. THE LT ENG PRSOV, BAR & SENSOR 390 WERE REPLACED IAW AMM 36-11-04, AMM 36-11-03 & AMM 36-12-03. DURING TESTS, IT WAS DETECTED THE HIGH STAGE VLV WITH FAILURE OF MODULATING, SO THE HIGH STAGE VLV WAS DEFERRED IAW MEL 36-9 CAT C. ACFT WAS SENT TO THE HANGAR & REPLACED THE HIGH STAGE VLV & HIGH STAGE REGULATOR IAW AMM 36-11-06 & AMM 36-11-07. TESTED CORRECT & THE REPORT WAS CLOSED.