What was found
AIRCRAFT WAS NOT GNDED. AIR INTERRUPT, EMER WAS DECLARED, LANDING UNEVENTFUL & ACFT NOT OVERWEIGHT. DURING CLIMB THE ACFT DE-PRESSURIZED RESULTING IN A CABIN ALT WARNING & CABIN ALT CLIMBING ABOVE 10,000 FEET. DURING DESCENT THE ACFT NOT ONLY PRESSURIZED TO BELOW SEA LEVEL. MANUAL DE-PRESSURIZATION WAS USED TO DESCEND & DE-PRESSURIZE THE ACFT. ACCOMPLISHED BITE OF BOTH CONTROLLERS & OPERATIONAL CHECK WITH NO DEFECTS FOUND. OK FOR SERVICE IAW AMM 21-32-00-101.