What was found
DECLARED EMERGENCY, ON DESCENT APPROX 29,000FT DURING 1000 FPM DESCENT. RECEIVED CABIN ALT WARNING HORN (CABIN WAS AT 10,000 AND CLIMBING), EXECUTED APPROPRIATE CHECK LIST, DEPLOYED PAX O2 MASK AND DECLARED EMERGENCY TO CONTINUE DESCENT. REMOVED AND REPLACED NR 2 ENGINE PNEUMATIC BLEED HIGH PRESS REGULATOR. REMOVED AND REPLACED MAIN OUTFLOW VALVE.