ALTDEV ALT OVERSHOT IN CLB.

Narrative

ON THE CLBOUT OF THE DAY'S FIRST FLT; WE MISSED OUR ASSIGNED ALT. THE FO WAS FLYING (MYSELF). AS WE CLBED OUT; I LOOKED UP TO SEE 31000 FT SET IN THE ALT WINDOW. I REMEMBERED SEEING WHAT I THOUGHT WAS OUR INITIAL ALT RESTR (3000 FT) ON THE GND. SINCE I SAW 31000 FT SET; I ASSUMED THAT THE CAPT HAD SET IT. I COULDN'T REMEMBER IF I HAD READ IT BACK AND NEVER QUESTIONED WHETHER I HAD. PASSING THROUGH 11000 FT I REMARKED THAT THESE EARLY MORNING SUNDAY FLTS ARE NICE BECAUSE THEY GIVE US THE HIGH ALTS RIGHT AWAY. AT THAT POINT THE CAPT SAID HE HADN'T SET 31000 FT. WE BOTH LOOKED DOWN TO DISCOVER THAT WE WERE STILL ON TWR FREQ. (OUR INITIAL CLRNC WAS TO 8000 FT.) SUPPLEMENTAL INFORMATION FROM ACN 255036: TWR DID NOT SWITCH US TO DEP CTL SO I ASKED TO SWITCH OVER. WE WERE CLBING THROUGH ABOUT 10000 FT; WHEN I CALLED DEP AND I REALIZED WE NORMALLY WERE ONLY CLRED TO 8000 FT. AT THE SAME TIME I SAW THE ALT SET WINDOW WAS SET AT 31000 FT. DEP CTL IMMEDIATELY CLRED US TO THE NORMAL 15000 FT UPON OUR CHKIN AND WE CONTINUED OUR CLB. APPARENTLY THE ALT WINDOW HAD BEEN SET AT 31000 FT SINCE WE FIRST PWRED THE ACFT. THERE WERE NO TFC CONFLICT.