Narrative:

During climb out of dtw and climbing through 10000 ft noticed cabin rate of climb slightly higher than normal. Attempted to adjust rate down on automatic controller. When cabin controller reached 10500 ft, we initiated a rapid descent to 10000 ft with ATC approval and completed the loss of pressurization checklist and returned to dtw with no other incident.

Google
 

Original NASA ASRS Text

Title: FLC OF A DC9-30 RETURN LAND AFTER THE CABIN WAS NOT PRESSURIZING.

Narrative: DURING CLBOUT OF DTW AND CLBING THROUGH 10000 FT NOTICED CABIN RATE OF CLB SLIGHTLY HIGHER THAN NORMAL. ATTEMPTED TO ADJUST RATE DOWN ON AUTO CONTROLLER. WHEN CABIN CONTROLLER REACHED 10500 FT, WE INITIATED A RAPID DSCNT TO 10000 FT WITH ATC APPROVAL AND COMPLETED THE LOSS OF PRESSURIZATION CHKLIST AND RETURNED TO DTW WITH NO OTHER INCIDENT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.