Narrative:

Flight departed the gate in heavy wet snow with visibility at about 1 mi. We were both unfamiliar with deicing procedures at toronto, but after completing very complicated procedures, we were on our way to runway 23. Our holdover time was going to be 30 mins. Taxi route was very lengthy (deice pad for runway 33L, taxiway F2 to taxiway H with many hold shorts in between). At approach end of runway 23 on taxiway H, ground switched us to tower, at which time we informed them we were ready to go. Tower told us to hold short for a vehicle and an arrival. After vehicle moved out of the way the captain moved the aircraft closer to runway 23. Aircraft was facing north toward taxiway I. Captain said he was going to move up and use full length. As he began to move aircraft, tower asked where we were going and sent arriving aircraft around. There were several contributing factors to this incident: reduced visibility, heavy snow, short holdover time, night operation, unfamiliar airport, crew members were unfamiliar with each other (second leg of day). Human performance factors: I made a bad assumption, we were so close to runway and I never considered the captain would cross a hold line at this point. I did not doublechk when he said he was going to use full length. I believe I was distraction by calculating the expiration of our holdover time. Additionally, it did not look like there should have been a hold line at that point on the taxiway as you cannot get any closer to the runway by continuing.

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Original NASA ASRS Text

Title: MLG CREW HAD RWY INCURSION AT CYYZ.

Narrative: FLT DEPARTED THE GATE IN HVY WET SNOW WITH VISIBILITY AT ABOUT 1 MI. WE WERE BOTH UNFAMILIAR WITH DEICING PROCS AT TORONTO, BUT AFTER COMPLETING VERY COMPLICATED PROCS, WE WERE ON OUR WAY TO RWY 23. OUR HOLDOVER TIME WAS GOING TO BE 30 MINS. TAXI RTE WAS VERY LENGTHY (DEICE PAD FOR RWY 33L, TXWY F2 TO TXWY H WITH MANY HOLD SHORTS IN BTWN). AT APCH END OF RWY 23 ON TXWY H, GND SWITCHED US TO TWR, AT WHICH TIME WE INFORMED THEM WE WERE READY TO GO. TWR TOLD US TO HOLD SHORT FOR A VEHICLE AND AN ARR. AFTER VEHICLE MOVED OUT OF THE WAY THE CAPT MOVED THE ACFT CLOSER TO RWY 23. ACFT WAS FACING N TOWARD TXWY I. CAPT SAID HE WAS GOING TO MOVE UP AND USE FULL LENGTH. AS HE BEGAN TO MOVE ACFT, TWR ASKED WHERE WE WERE GOING AND SENT ARRIVING ACFT AROUND. THERE WERE SEVERAL CONTRIBUTING FACTORS TO THIS INCIDENT: REDUCED VISIBILITY, HVY SNOW, SHORT HOLDOVER TIME, NIGHT OP, UNFAMILIAR ARPT, CREW MEMBERS WERE UNFAMILIAR WITH EACH OTHER (SECOND LEG OF DAY). HUMAN PERFORMANCE FACTORS: I MADE A BAD ASSUMPTION, WE WERE SO CLOSE TO RWY AND I NEVER CONSIDERED THE CAPT WOULD CROSS A HOLD LINE AT THIS POINT. I DID NOT DOUBLECHK WHEN HE SAID HE WAS GOING TO USE FULL LENGTH. I BELIEVE I WAS DISTR BY CALCULATING THE EXPIRATION OF OUR HOLDOVER TIME. ADDITIONALLY, IT DID NOT LOOK LIKE THERE SHOULD HAVE BEEN A HOLD LINE AT THAT POINT ON THE TXWY AS YOU CANNOT GET ANY CLOSER TO THE RWY BY CONTINUING.

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.