What was found
UPON RUN UP, PILOT CYCLED BOOTS. BOOT CYCLE STATUS LIGHT CAME ON BUT EXTINGUISHED BEFORE 6 SECOND INFLATION CYCLE TIMED OUT. (PRESS TO TEST SHOWED LAMP OK) BOOTS REMAINED PARTIALLY INFLATED AND WOULD NOT DE-FLATE. PILOT SPOOLED ENGINES DOWN AND BOOTS DE-INFLATED. INSPECTION DISCLOSED THAT DIAPHRAGM ON LOW PRESSURE REGULATOR OF THE AIRBORNE 2H22-16 ASSEMBLY HAD FAILED AROUND ENTIRE CIRCUMFERENCE. FAILED DISK SPALLED THE BELL SHAPED PORTION OF REGULATOR RUINING THE REGULATOR AND RENDERING 2H22-16 PART UNFIT FOR OVERHAUL.