Narrative:

The problem arose while giving instruction in an small aircraft during the taxiing phase. While driving to the airport I thought I saw several airplanes takeoff on runway 19. While in the airplane, I had allowed myself to become too engrossed with teaching the student how to taxi the airplane. I heard the controller's taxi clearance which told me to taxi to runway 32. However, I unconsciously followed the taxiways which led to runway 19. This had me crossing the active runway (19) while traffic (another single engine low wing aircraft) was taking off. I had discovered the problem when I saw the traffic taking off and becoming airborne about 200-300 ft to my left, it passed overhead by approximately 150 ft. When I saw the aircraft, I taxied as quickly as possible across the active runway. I didn't pay attention to the controller's authorization/instructions and I let myself concentrate too much on the student's performance. I allowed myself to automatically respond to my belief of what I thought was the active runway. Being familiar with the airport I became complacent and did not give the situation the respect or attention it deserved. I could have avoided this situation by being more alert and by simply writing down the clearance or taxi instructions on a note pad.

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Original NASA ASRS Text

Title: INSTRUCTOR WITH SPI CROSSES ACTIVE RWY WITHOUT CLRNC.

Narrative: THE PROBLEM AROSE WHILE GIVING INSTRUCTION IN AN SMA DURING THE TAXIING PHASE. WHILE DRIVING TO THE ARPT I THOUGHT I SAW SEVERAL AIRPLANES TKOF ON RWY 19. WHILE IN THE AIRPLANE, I HAD ALLOWED MYSELF TO BECOME TOO ENGROSSED WITH TEACHING THE STUDENT HOW TO TAXI THE AIRPLANE. I HEARD THE CTLR'S TAXI CLRNC WHICH TOLD ME TO TAXI TO RWY 32. HOWEVER, I UNCONSCIOUSLY FOLLOWED THE TAXIWAYS WHICH LED TO RWY 19. THIS HAD ME XING THE ACTIVE RWY (19) WHILE TFC (ANOTHER SINGLE ENG LOW WING ACFT) WAS TAKING OFF. I HAD DISCOVERED THE PROBLEM WHEN I SAW THE TFC TAKING OFF AND BECOMING AIRBORNE ABOUT 200-300 FT TO MY L, IT PASSED OVERHEAD BY APPROX 150 FT. WHEN I SAW THE ACFT, I TAXIED AS QUICKLY AS POSSIBLE ACROSS THE ACTIVE RWY. I DIDN'T PAY ATTN TO THE CTLR'S AUTHORIZATION/INSTRUCTIONS AND I LET MYSELF CONCENTRATE TOO MUCH ON THE STUDENT'S PERFORMANCE. I ALLOWED MYSELF TO AUTOMATICALLY RESPOND TO MY BELIEF OF WHAT I THOUGHT WAS THE ACTIVE RWY. BEING FAMILIAR WITH THE ARPT I BECAME COMPLACENT AND DID NOT GIVE THE SITUATION THE RESPECT OR ATTN IT DESERVED. I COULD HAVE AVOIDED THIS SITUATION BY BEING MORE ALERT AND BY SIMPLY WRITING DOWN THE CLRNC OR TAXI INSTRUCTIONS ON A NOTE PAD.

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.