LEAR 35A FLT CREW HAS A RWY INCURSION AT ILG.

Narrative

THE NEAR RWY INCURSION OCCURRED DURING TAXI TO THE ACTIVE RWY FOR TKOF. AT THE TIME I WAS ACTING AS THE PF AND WAS ACTIVELY TAXIING THE ACFT. THE CAPT WAS SETTING UP THE FLT PLAN IN THE FMS; WAS SPEAKING WITH GND CTL AND HAD THE ARPT DIAGRAM ATTACHED TO HIS YOKE. GND CTL CLRED US TO TAXI TO THE ACTIVE RWY 19. I DO NOT BELIEVE THAT THEY GAVE SPECIFIC TAXI INSTRUCTIONS. ALTHOUGH THE ACFT IS BASED AT THIS ARPT; RWY 19 IS AN UNUSUAL RWY FOR DEP BECAUSE THE TYPICAL RWY 27 WAS CLOSED. THE CAPT TOLD ME TO TAXI TO RWY 19 AND POINTED OUT THE INITIAL DIRECTION. WE CAME TO A 3-WAY INTXN AND I BEGAN TO TAKE THE TXWY I THOUGHT WAS CORRECT. THE CAPT POINTED OUT ANOTHER TXWY AND INDICATED THAT WAS THE CORRECT WAY. ULTIMATELY THIS TURNED OUT TO BE INCORRECT; BUT I DO NOT BELIEVE THAT IS THE ULTIMATE CAUSE OF THE NEAR RWY INCURSION. WE CAME TO A HOLD SHORT LINE FOR RWY 19 AND I STOPPED THE ACFT AT THE HOLD SHORT LINE. WE HAD A SHORT DISCUSSION ABOUT WHERE WE WERE ON THE FIELD. THE CAPT THOUGHT THAT WE WERE AT RWY 27 (ALTHOUGH I LEARNED THIS AFTER THE INCIDENT) AND TOLD ME TO TAXI OUT ON THE RWY TO JOIN TXWY B. I ASKED IF HE WAS SURE THAT'S WHERE WE WERE AND HE SAID YES. I HAD MY DOUBTS BUT TOOK HIS INSTRUCTION AND BEGAN TO MOVE THE ACFT. GND CTL QUICKLY TOLD US TO STOP AND WE DID ONLY SLIGHTLY BEYOND THE HOLD SHORT LINE. THEY TOLD US THAT WE WERE ABOUT TO TAXI ONTO AN ACTIVE RWY; GAVE US A 180 DEGS; PROGRESSIVE TAXI INSTRUCTIONS AND A LITTLE BIT OF A TONGUE LASHING (WELL DESERVED).