Narrative:

We were cleared to taxi to runway 28L at taxiway P via taxiway V and runway 28C. Captain repeated the clearance after I responded to ground control. Prior to reaching taxiway P; all checklists were complete and we were observing sterile cockpit rules. We both failed to see the taxiway P and we crossed runway 32 without a clearance. We both realized once we were on runway 32 that we had missed the taxiway. We both said that because we were taxiing on a runway that crossing another runway looks different than if you are on a taxiway and approaching a runway. We normally would not use this runway as a taxiway. There were no conflicts with other aircraft. Tower then cleared us for takeoff from runway 28L; full length. We both had our taxi charts on our clipboards but because this was our home airport; I did not look at it. I should have reviewed it anyway and that may have reminded me of the close proximity of runway 32 to taxiway P.

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Original NASA ASRS Text

Title: B737-400 FLT CREW HAS A RWY INCURSION AT PIT.

Narrative: WE WERE CLRED TO TAXI TO RWY 28L AT TXWY P VIA TXWY V AND RWY 28C. CAPT REPEATED THE CLRNC AFTER I RESPONDED TO GND CTL. PRIOR TO REACHING TXWY P; ALL CHKLISTS WERE COMPLETE AND WE WERE OBSERVING STERILE COCKPIT RULES. WE BOTH FAILED TO SEE THE TXWY P AND WE CROSSED RWY 32 WITHOUT A CLRNC. WE BOTH REALIZED ONCE WE WERE ON RWY 32 THAT WE HAD MISSED THE TXWY. WE BOTH SAID THAT BECAUSE WE WERE TAXIING ON A RWY THAT XING ANOTHER RWY LOOKS DIFFERENT THAN IF YOU ARE ON A TXWY AND APCHING A RWY. WE NORMALLY WOULD NOT USE THIS RWY AS A TXWY. THERE WERE NO CONFLICTS WITH OTHER ACFT. TWR THEN CLRED US FOR TKOF FROM RWY 28L; FULL LENGTH. WE BOTH HAD OUR TAXI CHARTS ON OUR CLIPBOARDS BUT BECAUSE THIS WAS OUR HOME ARPT; I DID NOT LOOK AT IT. I SHOULD HAVE REVIEWED IT ANYWAY AND THAT MAY HAVE REMINDED ME OF THE CLOSE PROX OF RWY 32 TO TXWY P.

Data retrieved from NASA's ASRS site as of January 2009 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.