What was found
CLIMBING THROUGH 12,000FT THE CABIN ALT WARNING ANNUNCIATOR CAME ON. MEMORY ITEMS WERE CARRIED OUT AND AN EMERGENCY DECLARED WITH A RETURN TO KPBI. COMPLIED WITH PRESSURIZATION OPERATIONAL CHECKS, CONFIRMED OPERATIONAL CHECKS WERE GOOD IN AIR MODE AND NO FAULTS FOUND. ALL WORK DONE REF CE560XL MM 21-30-00. NO OTHER DEFECTS NOTED AT THIS TIME. PER CUSTOMER REQUEST COMPLY WITH THE CABIN PRESSURE CONTROLLER BIT TEST, COMPLIED WITH BIT TEST AS REQUIRED AND SYSTEM TEST CHECKS GOOD WITH NO DEFECTS. ALL WORK DONE REF CE560XL MM 21-30-00. NO OTHER DEFECTS NOTED AT THIS TIME.