What was found
MOMENTARY SPIKE IN CABIN ALTITUDE AT 2,500 FPM CLIMB. AIRCRAFT BEGAN DUMPING PRESSURIZATION AT 2,200 AND FPM AT 7,000 FEET ALTITUDE. DURING CLIMB, PROBLEM OCCURRED WHEN SCHEDULING AND 600 FIELD ELEVATION. AT 17,000 FEET, AIRCRAFT BEGAN TO DEPRESSURIZE AT 2,200 AND FPM. CREW THEN CANCELLED ASCENT AND RETURNED TO A LOWER ALTITUDE. AIRCRAFT RETURNED TO COLUMBUS WITHOUT FURTHER INCIDENT.