What was found
ATL-IAD - FLT 192 - DURING CLIMB-OUT, AUTO PRESSURIZATION WENT INOP AND ACFT DEPRESSURIZED AT APPROXIMATELY 10,000 FEET. OXYGEN MASKS IN CABIN DEPLOYED AND CREW PRESSURIZED ACFT MANUALLY. UPON ARRIVAL IN IAD, OXYGEN MASKS WERE STOWED AND AUTO PRESSURIZATION PLACED ON MEL.