Narrative:

As captain, we proceeded with the checklists before pushing out of the gate at ord for flight to clt. We completed the before start checklist (completing the departure review with my understanding that a clearance was received by the first officer). We called for pushback, contacted metering, ord ground control, and tower with a takeoff clearance. On departure the controller instructed us to squawk a transponder code. I thought that the first officer had just failed to put in the correct transponder code prior to departure. We proceeded to our destination without incident. Contributing factor was in the departure review, I did not specifically ask if the clearance was received and what was the correct/new transponder code. This was also the last leg of our 3-DAY trip home which perhaps added to our complacency. Supplemental information from acn 399016: as the first officer, I set up the cockpit for flight from ord to clt. Having flown in and out of ord a lot, I set up everything except getting a clearance about 45 mins before departure. We did all checklists and failed to catch that I had not gotten our clearance yet on the before start checklist (item-departure review).

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Original NASA ASRS Text

Title: AN ACR B737 FLC DEPARTED WITHOUT AN IFR ENRTE CLRNC.

Narrative: AS CAPT, WE PROCEEDED WITH THE CHKLISTS BEFORE PUSHING OUT OF THE GATE AT ORD FOR FLT TO CLT. WE COMPLETED THE BEFORE START CHKLIST (COMPLETING THE DEP REVIEW WITH MY UNDERSTANDING THAT A CLRNC WAS RECEIVED BY THE FO). WE CALLED FOR PUSHBACK, CONTACTED METERING, ORD GND CTL, AND TWR WITH A TKOF CLRNC. ON DEP THE CTLR INSTRUCTED US TO SQUAWK A XPONDER CODE. I THOUGHT THAT THE FO HAD JUST FAILED TO PUT IN THE CORRECT XPONDER CODE PRIOR TO DEP. WE PROCEEDED TO OUR DEST WITHOUT INCIDENT. CONTRIBUTING FACTOR WAS IN THE DEP REVIEW, I DID NOT SPECIFICALLY ASK IF THE CLRNC WAS RECEIVED AND WHAT WAS THE CORRECT/NEW XPONDER CODE. THIS WAS ALSO THE LAST LEG OF OUR 3-DAY TRIP HOME WHICH PERHAPS ADDED TO OUR COMPLACENCY. SUPPLEMENTAL INFO FROM ACN 399016: AS THE FO, I SET UP THE COCKPIT FOR FLT FROM ORD TO CLT. HAVING FLOWN IN AND OUT OF ORD A LOT, I SET UP EVERYTHING EXCEPT GETTING A CLRNC ABOUT 45 MINS BEFORE DEP. WE DID ALL CHKLISTS AND FAILED TO CATCH THAT I HAD NOT GOTTEN OUR CLRNC YET ON THE BEFORE START CHKLIST (ITEM-DEP REVIEW).

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.