Narrative:

Ground gave clearance to taxi to runway 28R via txwys B and B2. At B2 we received clearance to take off from the relocated threshold. I was doing the line-up check and all I noticed was the runway end lights out my window; so I assumed we were at the beginning of the runway. As the captain started to add power; I looked up and saw a yellow taxiway line and 1000 ft down was the relocated threshold. At that time the tower said the threshold was 1000 ft further down; but we had already started the roll. I had been unsure as to the meaning of our instructions. I thought the threshold had been relocated from B1 to B2 and that we were cleared for takeoff at that point. I did not realize until after takeoff power had been set that we were to taxi down the runway another 1000 ft before adding power. The last time I was at pit; the tower had us back taxi from B3 to the threshold; so I never saw the taxi line extending further down to B2. The only reason I report this is because if people were working in the area behind B2; they could have been hurt by our jet blast. Also; I guess ATC could have some case of us adding takeoff power on what was considered a taxiway. This is a situation that I think warrants a specific chart to show pilots what has changed on runway 28R and show exactly where the threshold is now located. ATC did not say anything further about the incident; but when he switched us to departure; he didn't sound happy.

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Original NASA ASRS Text

Title: FLT CREW OF E145 TAKES OFF FROM RWY 28R AT PIT PRIOR TO RELOCATED THRESHOLD.

Narrative: GND GAVE CLRNC TO TAXI TO RWY 28R VIA TXWYS B AND B2. AT B2 WE RECEIVED CLRNC TO TAKE OFF FROM THE RELOCATED THRESHOLD. I WAS DOING THE LINE-UP CHK AND ALL I NOTICED WAS THE RWY END LIGHTS OUT MY WINDOW; SO I ASSUMED WE WERE AT THE BEGINNING OF THE RWY. AS THE CAPT STARTED TO ADD PWR; I LOOKED UP AND SAW A YELLOW TXWY LINE AND 1000 FT DOWN WAS THE RELOCATED THRESHOLD. AT THAT TIME THE TWR SAID THE THRESHOLD WAS 1000 FT FURTHER DOWN; BUT WE HAD ALREADY STARTED THE ROLL. I HAD BEEN UNSURE AS TO THE MEANING OF OUR INSTRUCTIONS. I THOUGHT THE THRESHOLD HAD BEEN RELOCATED FROM B1 TO B2 AND THAT WE WERE CLRED FOR TKOF AT THAT POINT. I DID NOT REALIZE UNTIL AFTER TKOF PWR HAD BEEN SET THAT WE WERE TO TAXI DOWN THE RWY ANOTHER 1000 FT BEFORE ADDING PWR. THE LAST TIME I WAS AT PIT; THE TWR HAD US BACK TAXI FROM B3 TO THE THRESHOLD; SO I NEVER SAW THE TAXI LINE EXTENDING FURTHER DOWN TO B2. THE ONLY REASON I RPT THIS IS BECAUSE IF PEOPLE WERE WORKING IN THE AREA BEHIND B2; THEY COULD HAVE BEEN HURT BY OUR JET BLAST. ALSO; I GUESS ATC COULD HAVE SOME CASE OF US ADDING TKOF PWR ON WHAT WAS CONSIDERED A TXWY. THIS IS A SITUATION THAT I THINK WARRANTS A SPECIFIC CHART TO SHOW PLTS WHAT HAS CHANGED ON RWY 28R AND SHOW EXACTLY WHERE THE THRESHOLD IS NOW LOCATED. ATC DID NOT SAY ANYTHING FURTHER ABOUT THE INCIDENT; BUT WHEN HE SWITCHED US TO DEP; HE DIDN'T SOUND HAPPY.

Data retrieved from NASA's ASRS site as of January 2009 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.