RWY INCURSION WITH ARRIVING TFC APCHING.

Narrative

OUR FLT WAS CLRED TO TAXI TO AND HOLD SHORT OF RWY 22. RWY ASSIGNMENT WAS RWY 27 FOR DEP. CLRNC WAS ISSUED BEFORE WE LEFT THE CHOCKS. WE WERE TAXIING ACROSS RWY 22 BEFORE WE REALIZED THE MISTAKE. GND CTL IMMEDIATELY ASKED US TO EXPEDITE ACROSS RWY 22. THIS COM WAS THE ALERT. NO IMMEDIATE CONFLICT REQUIRING EVASIVE ACTION WAS NOTED. NONE THE LESS THE ERROR OCCURRED. A SMALL SINGLE ACFT WAS ON FINAL; BUT IN NO DANGER. THE ACFT WAS 1 TO 1 1/2 MI OUT AFTER WE HAD CROSSED. RWY INCURSIONS ARE A BIG AND SERIOUS ISSUE. THIS IS CLRLY UNDERSTOOD. I HAVE FLOWN PROFESSIONALLY FOR 26 YRS; AND THIS IS MY FIRST INCURSION. MY WORK ENCOMPASSES FLY; ADMINISTRATING; BUDGETING; FORECASTING (FINANCIAL) IN BOTH PART 91 AND PART 135 OPS. THIS FLT OCCURRED AFTER A FULL MORNING IN THE OFFICE. HAVING FLOWN FROM OSH FOR 20 YRS; 90% OF OUR TKOFS ARE ON RWY 27. RWY 22 IS SELDOM USED ALTHOUGH OPEN. THE ERROR IS A PRODUCT OF 'CONDITIONAL RESPONSE;' INEXPERIENCE OF A NEW COPLT; PREOCCUPATION WITH THE 'CHALLENGE AND RESPONSE' CHKLIST ACTIVITY AND POSSIBLE OVERLOAD. WHEN CLRED TO TAXI; A 'HOLD SHORT' CLRNC IS SELDOM GIVEN; DUE TO THE LOW ACTIVITY AT THIS ARPT; THUS THE CONDITIONAL RESPONSE. SINCE THE INCIDENT; WE HAVE CHANGED OUR TAXI OUT PROCS TO WITHHOLD ALL CHKLIST ACTIVITY UNTIL AT RWY HOLD LINES. BOTH EYES MUST BE OUT OF THE COCKPIT AND 'FLYING' THE TRIP; THIS INCLUDES TAXIING OUT; FLYING AND TAXIING IN. IT MAKES A GOOD; BUT UNFORTUNATE WAKEUP CALL.