Narrative:

After receiving a taxi clearance, the aircraft was taxied to runway 29. While at the hold short line the controller (apparently) again cleared the aircraft to taxi to runway 29. This communication sounded like 'taxi onto runway 29,' and the aircraft was taxied onto the runway into position for takeoff. It was discovered later that the radio had been inadvertently left on the ground control frequency.

Google
 

Original NASA ASRS Text

Title: CHARTER ACFT CLEARED TO TAXI TO RWY AND HOLD. HEARS SECOND CALL BUT MISINTERPS AND TAXIS ONTO RWY FOR TKOF.

Narrative: AFTER RECEIVING A TAXI CLRNC, THE ACFT WAS TAXIED TO RWY 29. WHILE AT THE HOLD SHORT LINE THE CTLR (APPARENTLY) AGAIN CLRED THE ACFT TO TAXI TO RWY 29. THIS COM SOUNDED LIKE 'TAXI ONTO RWY 29,' AND THE ACFT WAS TAXIED ONTO THE RWY INTO POS FOR TKOF. IT WAS DISCOVERED LATER THAT THE RADIO HAD BEEN INADVERTENTLY LEFT ON THE GND CTL FREQ.

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.