A B737 taxies at mdw, il, and has a runway incursion at runway 31R.

Attributes
ACN	383861
Time
Date	199710
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mdw
State Reference	IL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : rno
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground other : taxi
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Cessna Single Piston Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	descent : approach landing other
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 250 flight time total : 12500 flight time type : 8000
ASRS Report	383861
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : atp
Experience	flight time last 90 days : 270 flight time total : 5000 flight time type : 3000
ASRS Report	383860
Events
Anomaly	incursion : runway non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : exited adverse environment
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

After pushback from gate xx at mdw, we were accomplishing the after start checks and called ground for taxi. We were cleared to taxi to the active (runway 31C). Upon start of taxi, I asked the first officer if we were cleared to cross runway 31R. He answered 'no I think he said to hold short of the right.' I then said I'm sure he said to cross the right, looked and didn't see any traffic and started across the runway 31R. As we were crossing the right runway the ground controller quickly stated 'call sign, the call was hold short of runway 31R, expedite across to runway 31C traffic on final for the right.' at that time I looked again and saw a light single on about a 1 1/2 mi final for the right runway. There were no evasive actions or conflicts by any aircraft. We crossed and continued for takeoff. I think what made this situation confusing was the clearance to taxi to the center runway followed by the instruction to hold short of the closer, right runway. If the clearance had been given to hold short of the right first for taxi to the center runway, I may not have mistakenly thought I was cleared to the active and crossed the right. Supplemental information from acn 383860: we started our short taxi (approximately 200 ft) and the captain asked me if we were cleared to cross runway 31R. I told him I thought the clearance included 'hold short' of runway 31R, and he said he thought it was to cross runway 31R to runway 31C. As we were crossing runway 31R, ground called and said the clearance was 'to hold short of runway 31R, continue to cross runway 31R, traffic on final.' we continued to cross and hold short of runway 31C. We saw traffic on final runway 31R after we crossed. No evasive action was required by us or the cessna on final. I think the problem was that we're usually cleared 'cleared to cross runway 31R taxi to runway 31C.' and this time we were cleared 'to taxi to runway 31C, hold short of runway 31R.' this created the confusion, and added with the short taxi and my checklist duties created the possible incursion.

Original NASA ASRS Text

Title: A B737 TAXIES AT MDW, IL, AND HAS A RWY INCURSION AT RWY 31R.

Narrative: AFTER PUSHBACK FROM GATE XX AT MDW, WE WERE ACCOMPLISHING THE AFTER START CHKS AND CALLED GND FOR TAXI. WE WERE CLRED TO TAXI TO THE ACTIVE (RWY 31C). UPON START OF TAXI, I ASKED THE FO IF WE WERE CLRED TO CROSS RWY 31R. HE ANSWERED 'NO I THINK HE SAID TO HOLD SHORT OF THE R.' I THEN SAID I'M SURE HE SAID TO CROSS THE R, LOOKED AND DIDN'T SEE ANY TFC AND STARTED ACROSS THE RWY 31R. AS WE WERE XING THE R RWY THE GND CTLR QUICKLY STATED 'CALL SIGN, THE CALL WAS HOLD SHORT OF RWY 31R, EXPEDITE ACROSS TO RWY 31C TFC ON FINAL FOR THE R.' AT THAT TIME I LOOKED AGAIN AND SAW A LIGHT SINGLE ON ABOUT A 1 1/2 MI FINAL FOR THE R RWY. THERE WERE NO EVASIVE ACTIONS OR CONFLICTS BY ANY ACFT. WE CROSSED AND CONTINUED FOR TKOF. I THINK WHAT MADE THIS SIT CONFUSING WAS THE CLRNC TO TAXI TO THE CTR RWY FOLLOWED BY THE INSTRUCTION TO HOLD SHORT OF THE CLOSER, R RWY. IF THE CLRNC HAD BEEN GIVEN TO HOLD SHORT OF THE R FIRST FOR TAXI TO THE CTR RWY, I MAY NOT HAVE MISTAKENLY THOUGHT I WAS CLRED TO THE ACTIVE AND CROSSED THE R. SUPPLEMENTAL INFO FROM ACN 383860: WE STARTED OUR SHORT TAXI (APPROX 200 FT) AND THE CAPT ASKED ME IF WE WERE CLRED TO CROSS RWY 31R. I TOLD HIM I THOUGHT THE CLRNC INCLUDED 'HOLD SHORT' OF RWY 31R, AND HE SAID HE THOUGHT IT WAS TO CROSS RWY 31R TO RWY 31C. AS WE WERE XING RWY 31R, GND CALLED AND SAID THE CLRNC WAS 'TO HOLD SHORT OF RWY 31R, CONTINUE TO CROSS RWY 31R, TFC ON FINAL.' WE CONTINUED TO CROSS AND HOLD SHORT OF RWY 31C. WE SAW TFC ON FINAL RWY 31R AFTER WE CROSSED. NO EVASIVE ACTION WAS REQUIRED BY US OR THE CESSNA ON FINAL. I THINK THE PROB WAS THAT WE'RE USUALLY CLRED 'CLRED TO CROSS RWY 31R TAXI TO RWY 31C.' AND THIS TIME WE WERE CLRED 'TO TAXI TO RWY 31C, HOLD SHORT OF RWY 31R.' THIS CREATED THE CONFUSION, AND ADDED WITH THE SHORT TAXI AND MY CHKLIST DUTIES CREATED THE POSSIBLE INCURSION.

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.