AN ACR B737-200 CREW MADE AN EMER DSCNT. THEY FOUND OUT LATER THAT THEY HAD NOT TURNED ON THE PRESSURIZATION SYS.

Narrative

BLEEDS OFF TKOF OUT OF TUL AND IMMEDIATE TURN TO E OFF OF RWY 36R; TO AVOID TSTMS. I WAS FLYING AND CONTINUED TO RETUNE RADAR AND MAKE COURSE ADJUSTMENTS FOR A BETTER RIDE (DEVS WERE APPROVED BY ATC). TURB WAS LIGHT TO MODERATE; SO I TOLD THE FLT ATTENDANTS TO REMAIN SEATED. CLBING THROUGH FL260 WE GOT AN 'AUTOFAIL' LIGHT ON OUR CABIN PRESSURIZATION SYS AND SWITCHED TO 'STANDBY' MODE. THE CABIN ALT CONTINUED TO CLB; SO THE FO SWITCHED TO MANUAL AND TRIED TO CLOSE THE OUTFLOW VALVE. NEXT WE GOT THE ALT WARNING HORN FOR THE CABIN AND THE MASKS DEPLOYED. WE ACCOMPLISHED AN EMER DSCNT WITH ATC CONCURRENCE AND COMPLETED THE FLT AT 10000 FT WITH NO FURTHER INCIDENT. I LATER CHKED WITH MAINT CONCERNING THAT ACFT AND LEARNED THAT THE PRESSURIZATION SYS CHKED OUT OK. I THEN DISCUSSED IT WITH MY FO AND WE NOW BELIEVE WE FAILED TO RECONFIGURE THE PRESSURIZATION SYS WITH ENG BLEEDS 'ON' AND THE APU BLEED 'OFF' AFTER OUR INITIAL NO BLEEDS TKOF. WE IMMEDIATELY FLEW TO MEET WITH OUR CHIEF PLT AND SUBMITTED AN IRREGULARITY RPT. SUPPLEMENTAL INFO FROM ACN 339975: 11 1/2 HRS INTO CREW DUTY DAY. RETURNED FROM MCI AFTER HOLDING FOR OVER 1 HR. OVER 1 HR 15 MINS ON GND TO RESOLVE PLAN.