Narrative:

Issued clearance to fly direct ord for vectors to runway 9R. Read back to controller as same. Left turn made direct ord. Approximately 3 mins later controller issued clearance to turn right heading 270 degrees. He then stated that our previous clearance was pappi, intersection then direct ord. I believe that in O'hare approach controls effort to handle traffic, they speak before keying microphone. At times this must have been the case here. We read back what we heard with no further comment from approach control until 'right to a 270 degrees heading clearance.' supplemental information from acn 147172. I believe that sometimes when controllers are under high workloads they sometimes begin to talk before keying the microphone and often times do not properly listen to readback.

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Original NASA ASRS Text

Title: LGT FLT CREW HEARD AND READBACK CLRNC DIRECT ORD. CTLR LATER SAID CLRNC DIRECT PAPPI, THEN DIRECT ORD.

Narrative: ISSUED CLRNC TO FLY DIRECT ORD FOR VECTORS TO RWY 9R. READ BACK TO CTLR AS SAME. L TURN MADE DIRECT ORD. APPROX 3 MINS LATER CTLR ISSUED CLRNC TO TURN R HDG 270 DEGS. HE THEN STATED THAT OUR PREVIOUS CLRNC WAS PAPPI, INTXN THEN DIRECT ORD. I BELIEVE THAT IN O'HARE APCH CTLS EFFORT TO HANDLE TFC, THEY SPEAK BEFORE KEYING MIC. AT TIMES THIS MUST HAVE BEEN THE CASE HERE. WE READ BACK WHAT WE HEARD WITH NO FURTHER COMMENT FROM APCH CTL UNTIL 'R TO A 270 DEGS HDG CLRNC.' SUPPLEMENTAL INFO FROM ACN 147172. I BELIEVE THAT SOMETIMES WHEN CTLRS ARE UNDER HIGH WORKLOADS THEY SOMETIMES BEGIN TO TALK BEFORE KEYING THE MIC AND OFTEN TIMES DO NOT PROPERLY LISTEN TO READBACK.

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.