Crossed cleared runway 13L. Thought departing runway 13C.

Attributes
ACN	171039
Time
Date	199102
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mdw
State Reference	IL
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	tower : lax
Operator	common carrier : air carrier
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Flight Phase	ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 300 flight time total : 2800
ASRS Report	171039
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 100 flight time total : 2500 flight time type : 150
ASRS Report	171323
Events
Anomaly	incursion : runway non adherence : clearance
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While taxiing to runway 13C (the one I believe was our assigned runway) I xed runway 13L. Ground told me, 'do you know you xed the departure runway?' I said I thought runway 13C was the assigned runway. They said no runway 13L was. Lack of communication between me and my first officer caused the problem. I never asked for clarification. At the time the clearance was issued I was busy with taxiing the aircraft out of the gate in close quarters to other aircraft. So I taxied to the runway I thought I heard. Listen closely and do not taxi until directions are clear. Be sure to ask the first officer what he heard. Never assume! Supplemental information from acn 171323. I had my head down looking at the pretkof checklist.

Original NASA ASRS Text

Title: CROSSED CLEARED RWY 13L. THOUGHT DEPARTING RWY 13C.

Narrative: WHILE TAXIING TO RWY 13C (THE ONE I BELIEVE WAS OUR ASSIGNED RWY) I XED RWY 13L. GND TOLD ME, 'DO YOU KNOW YOU XED THE DEP RWY?' I SAID I THOUGHT RWY 13C WAS THE ASSIGNED RWY. THEY SAID NO RWY 13L WAS. LACK OF COM BTWN ME AND MY F/O CAUSED THE PROB. I NEVER ASKED FOR CLARIFICATION. AT THE TIME THE CLRNC WAS ISSUED I WAS BUSY WITH TAXIING THE ACFT OUT OF THE GATE IN CLOSE QUARTERS TO OTHER ACFT. SO I TAXIED TO THE RWY I THOUGHT I HEARD. LISTEN CLOSELY AND DO NOT TAXI UNTIL DIRECTIONS ARE CLR. BE SURE TO ASK THE F/O WHAT HE HEARD. NEVER ASSUME! SUPPLEMENTAL INFO FROM ACN 171323. I HAD MY HEAD DOWN LOOKING AT THE PRETKOF CHKLIST.

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.