Narrative:

What was thought ground control said: cpr xy, cross runway 4L and stay with me. What ground control said: cpr xy, hold short runway 4L and stay with me. Both pilots in our aircraft did not catch proper instructions given by ground control and crossed the approach end of runway 4L on the way to runway 4R for departure. Controllers did not seem too concerned and we apologized for the misunderstanding. No traffic or aircraft on runway 4L during occurrence. Preventive measure: readback hold shorts. Clear left and right when crossing any runway. Be cautious when active runways are being changed, they had been using runway 31C for active, and were switching to runway 4L and 4R.

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Original NASA ASRS Text

Title: A CPR JET CROSSES RWY 4L WHEN GND CTLR HAD ADVISED THEM TO HOLD SHORT AT MDW, IL.

Narrative: WHAT WAS THOUGHT GND CTL SAID: CPR XY, CROSS RWY 4L AND STAY WITH ME. WHAT GND CTL SAID: CPR XY, HOLD SHORT RWY 4L AND STAY WITH ME. BOTH PLTS IN OUR ACFT DID NOT CATCH PROPER INSTRUCTIONS GIVEN BY GND CTL AND CROSSED THE APCH END OF RWY 4L ON THE WAY TO RWY 4R FOR DEP. CTLRS DID NOT SEEM TOO CONCERNED AND WE APOLOGIZED FOR THE MISUNDERSTANDING. NO TFC OR ACFT ON RWY 4L DURING OCCURRENCE. PREVENTIVE MEASURE: READBACK HOLD SHORTS. CLR L AND R WHEN XING ANY RWY. BE CAUTIOUS WHEN ACTIVE RWYS ARE BEING CHANGED, THEY HAD BEEN USING RWY 31C FOR ACTIVE, AND WERE SWITCHING TO RWY 4L AND 4R.

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.