What was found
DURING CLIMB AROUND 8,000 TO 9,000 FEET HEARD RUMBLE UNDER PILOTS FEET. A SHORT TIME AFTER, LOST CONTROL OF CABIN PRESSURE. PERFORMED LOSS OF PRESSURE VIBRATION CHECK LIST. UNABLE TO RESTORE CONTROL OF CABIN PRESSURE, RETURNED TO LAS. *S/D* DUCT SUPPORT ATTACHMENT, DOWNSTREAM OF THE WATER SEPARATOR, FAILED AND CAUSED DUCT SEPARATION. INTERIM REPAIR MADE TO DUCT SUPPORT ATTACH POINTS.