Narrative:

B727 departed den runway 8. Headed east at 10000 ft given a climb to 15000 ft and a turn to a north direction. Approaching 12000 ft departure control pointed out traffic at 13000 ft. Asked departure control to confirm altitude as 15000 ft, it was confirmed as 12000 ft. The aircraft was leveled at 12000 ft after reaching approximately 12500 ft. The problem was a miscom with departure control (an altitude clearance readback of 15000 ft was given to the controller).

Google
 

Original NASA ASRS Text

Title: FLC CLBS 500 FT ABOVE ASSIGNED ALT.

Narrative: B727 DEPARTED DEN RWY 8. HEADED E AT 10000 FT GIVEN A CLB TO 15000 FT AND A TURN TO A N DIRECTION. APCHING 12000 FT DEP CTL POINTED OUT TFC AT 13000 FT. ASKED DEP CTL TO CONFIRM ALT AS 15000 FT, IT WAS CONFIRMED AS 12000 FT. THE ACFT WAS LEVELED AT 12000 FT AFTER REACHING APPROX 12500 FT. THE PROB WAS A MISCOM WITH DEP CTL (AN ALT CLRNC READBACK OF 15000 FT WAS GIVEN TO THE CTLR).

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.