MD80 CREW HAD RWY INCURSION.

Narrative

CAPT TAXIED ACFT ONTO ACTIVE RWY 22 AT AVP. CLRNC WAS 'TAXI TO RWY 22.' FO WAS 'HEADS DOWN' COMPLETING TKOF CHKLIST; WHEN ACFT ENTERED ACTIVE RWY FROM AN UNLIT XING RWY. FO LOOKED UP; WHEN ACFT NOSE CROSSED ACTIVE RWY EDGE; AND ASKED/TOLD CAPT 'TAXI TO RWY 22' MEANS HOLD SHORT; NOT TAXI ONTO. CAPT SAID WE WERE CLRED TO 'TAXI TO RWY 22' SO CAPT COULD 'BACK TAXI' INTO TKOF POS (AT THE APCH END OF RWY). AS ACFT TAXIED ONTO THE ACTIVE RWY; TWR SAID 'CALL SIGN; WHERE ARE YOU GOING? I CLRED YOU TO TAXI TO RWY 22; BUT ANYWAY (CALL SIGN) YOU ARE CLRED FOR TKOF.' THIS WAS THE FIRST DEP OF THE MORNING (XA00). TWR/GND -- SINGLE CTLR. NO OTHER TFC ON FINAL OR OPERATING NEAR THE ACTIVE RWY AND TXWYS. BY THE TIME I REALIZED WHAT THE CAPT WAS DOING; IT WAS TOO LATE; THE ACFT WAS ON THE RWY. THE TURN ONTO THE 'CLOSED' INTXN RWY WAS A 30-45 DEG R TURN; MAYBE 100-200 FT TO THE ACTIVE RWY. 'A QUICK R AND QUICK L.' I DIDN'T HAVE A CHANCE AT APPLYING THE BRAKES TO STOP THE ACFT PRIOR TO THE ACFT ENTERING THE RWY.