As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHX/COS - FLT 2412 - AIR TURNBACK. ON CLIMB-OUT, A/C SYSTEM STARTED BLOWING EXTREMELY HIGH PRESSURE AIR OUT OF ALL AIR DUCTS IN THE COCKPIT. REMOVED AND REPLACED CONTROL CABIN MUFFLER. REMOVED AND REPLACED TURBO FAN. RAN BOTH PACKS WITH ENGINE BLEEDS. FLIGHT DECK AIR DISTRIBUTION SYSTEM NORMAL. PART TOTAL CYCLES, 8,039. REFERENCE: OPERATOR CONTROL NR 96ZZZX3991. (X)