Narrative:

I was departing pia and was cleared to taxi to the runway 8 at taxiway F. I called the tower that I was ready, at which point they cleared an aircraft for departure. I mistakenly thought they had cleared me for takeoff. I pulled out onto the runway, at which time the tower advised me that I had not been cleared to enter the runway. I then expedited clearing the runway, but could not fast enough and another aircraft had to go around.

Google
 

Original NASA ASRS Text

Title: PLT OF AN SMT TWIN ATX CARGO ACFT TAXIED ONTO RWY FOR TKOF PRIOR TO BEING CLRED ONTO THE RWY SINCE HE RESPONDED TO ANOTHER ACFT'S CLRNC CAUSING ANOTHER ACFT TO GO AROUND.

Narrative: I WAS DEPARTING PIA AND WAS CLRED TO TAXI TO THE RWY 8 AT TXWY F. I CALLED THE TWR THAT I WAS READY, AT WHICH POINT THEY CLRED AN ACFT FOR DEP. I MISTAKENLY THOUGHT THEY HAD CLRED ME FOR TKOF. I PULLED OUT ONTO THE RWY, AT WHICH TIME THE TWR ADVISED ME THAT I HAD NOT BEEN CLRED TO ENTER THE RWY. I THEN EXPEDITED CLRING THE RWY, BUT COULD NOT FAST ENOUGH AND ANOTHER ACFT HAD TO GO AROUND.

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.