Narrative:

While taxiing out from FBO at phl for departure on runway 27L, we were cleared via txwys a and D to hold short of runway 26. I was reading the taxi checklist to the PF, and performing various taxi items. We stopped and held short of runway 26 on taxiway D. We were then cleared to cross runway 26 and told to hold short of runway 35 on taxiway K. I read back the clearance, and the PF proceeded to taxi. I went back to performing checklist items, while reading from the checklist. I was not at the moment looking outside. We were moving south on taxiway D, which parallels runway 35, and intersects with runway 27R. Instead of turning right (west) on taxiway K to hold short of runway 35, the PF continued south on taxiway D and crossed runway 27R without clearance, expecting to hold short of runway 35 at the approach end on taxiway south. This error was brought to our attention by ground. At no time was there a conflict with another aircraft. We acknowledged the error, and were cleared to taxi to runway 27L, and departure. We are based at phl, and are very familiar with the environment. The usual route out to runway 27L is taxiway a, taxiway D crossing both runway 26 and runway 27R, when cleared, then cross runway 35 at taxiway south to runway 27L. We both heard the clearance, and I noted a nod from the PF, but the change to the 'usual' route apparently didn't register. I should not have had my head down performing cockpit duties while moving, thus removing a check on the PF. If I had been looking, I would have brought the error to his attention before he entered an active runway. Supplemental information from acn 537283: cleared to taxi across runway 26 on taxiway D hold short of runway 35 at taxiway K. Normal route to runway 27L is taxiway D across runway 26, runway 27R, hold short of runway 35 at taxiway south. I've done this route so many times that I must have been on automatic or something as I did cross runway 27R without a clearance to do so. Copilot was head down running the checklist and did not catch my error.

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Original NASA ASRS Text

Title: AN LJ55 CREW, TAXIING FOR TKOF AT PHL, TAXIED ACROSS AN ACTIVE RWY WITHOUT A CLRNC.

Narrative: WHILE TAXIING OUT FROM FBO AT PHL FOR DEP ON RWY 27L, WE WERE CLRED VIA TXWYS A AND D TO HOLD SHORT OF RWY 26. I WAS READING THE TAXI CHKLIST TO THE PF, AND PERFORMING VARIOUS TAXI ITEMS. WE STOPPED AND HELD SHORT OF RWY 26 ON TXWY D. WE WERE THEN CLRED TO CROSS RWY 26 AND TOLD TO HOLD SHORT OF RWY 35 ON TXWY K. I READ BACK THE CLRNC, AND THE PF PROCEEDED TO TAXI. I WENT BACK TO PERFORMING CHKLIST ITEMS, WHILE READING FROM THE CHKLIST. I WAS NOT AT THE MOMENT LOOKING OUTSIDE. WE WERE MOVING S ON TXWY D, WHICH PARALLELS RWY 35, AND INTERSECTS WITH RWY 27R. INSTEAD OF TURNING R (W) ON TXWY K TO HOLD SHORT OF RWY 35, THE PF CONTINUED S ON TXWY D AND CROSSED RWY 27R WITHOUT CLRNC, EXPECTING TO HOLD SHORT OF RWY 35 AT THE APCH END ON TXWY S. THIS ERROR WAS BROUGHT TO OUR ATTN BY GND. AT NO TIME WAS THERE A CONFLICT WITH ANOTHER ACFT. WE ACKNOWLEDGED THE ERROR, AND WERE CLRED TO TAXI TO RWY 27L, AND DEP. WE ARE BASED AT PHL, AND ARE VERY FAMILIAR WITH THE ENVIRONMENT. THE USUAL RTE OUT TO RWY 27L IS TXWY A, TXWY D XING BOTH RWY 26 AND RWY 27R, WHEN CLRED, THEN CROSS RWY 35 AT TXWY S TO RWY 27L. WE BOTH HEARD THE CLRNC, AND I NOTED A NOD FROM THE PF, BUT THE CHANGE TO THE 'USUAL' RTE APPARENTLY DIDN'T REGISTER. I SHOULD NOT HAVE HAD MY HEAD DOWN PERFORMING COCKPIT DUTIES WHILE MOVING, THUS REMOVING A CHK ON THE PF. IF I HAD BEEN LOOKING, I WOULD HAVE BROUGHT THE ERROR TO HIS ATTN BEFORE HE ENTERED AN ACTIVE RWY. SUPPLEMENTAL INFO FROM ACN 537283: CLRED TO TAXI ACROSS RWY 26 ON TXWY D HOLD SHORT OF RWY 35 AT TXWY K. NORMAL RTE TO RWY 27L IS TXWY D ACROSS RWY 26, RWY 27R, HOLD SHORT OF RWY 35 AT TXWY S. I'VE DONE THIS RTE SO MANY TIMES THAT I MUST HAVE BEEN ON AUTO OR SOMETHING AS I DID CROSS RWY 27R WITHOUT A CLRNC TO DO SO. COPLT WAS HEAD DOWN RUNNING THE CHKLIST AND DID NOT CATCH MY ERROR.

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.