What was found
RT DUCT FLUCTUATES + OR - 20 PSI. ACCOMPLISHED HPSOV HEALTH CHECK, REPLACED PRV PER AMM AND HPC PER AMM AGAIN, NO HELP. RT PNEUMATIC PRESSURE STILL FLUCTUATES 40-20, N2 77-80%, BLEED OFF LIGHT ILLUMINATED, ONLY HAPPENS ON DECELERATION. LOCKED OUT HPSOV PER MEL. SUSPECT M860 BLEED CONTROL CARD. PER CREW, IN CRUISE WITH HPSOV LOCKED CLOSED, DUCT PRESSURE IS STABLE AT 24PSI EACH SIDE. VERIFIED HIGH STAGE SYS REACTIVATED. PERFORMED BLEED SYS TEST WITH AIR LEED MON TEST & LAPTOP HOOKUP, AFTER PRSOV REPLACED BLEED PARAMETERS ALL CHECKED GOOD, NO VASCILLATIONS PRESENT.