Narrative:

At approximately XA55 local tower cleared an aircraft into position and hold on runway 28L at pit. We were the #1 aircraft in line for runway 28L. Flight number XXXX, we acknowledge 'position and hold XXXX' and proceeded into position on runway 28L. The tower then cleared XXXA for takeoff runway 28L, the XXXA flight acknowledge the takeoff but stated there was an aircraft on the runway. We then notified the tower that XXXX was on the runway tower then ordered us to clear and XXXA into position and hold. The XXXA flight was asked what he heard he stated 'we heard somebody cleared into position and hold we thought it was us but we were not #1 in line.' the XXXA then took off we were cleared on the runway for takeoff no further situation developed. This was well into our 12 hour of duty for the day or 7TH leg and already 6 hours and 40 min of flight time. The WX conditions for the day were low IMC and holding for approachs was occurring. At this point in time the crew's fatigue factor was high and thoughts were on the overnight at cho. It is apparent that a miscom occurred the XXXA flight never acknowledged position and hold we did. The tower did not catch the wrong readback nor the aircraft on the runway in position.

Related reports:

Google
 

Original NASA ASRS Text

Title: THE RPTR BEING #1 TAXIED INTO POS AND HOLD WHEN THE CTLR INSTRUCTED, WITHOUT HEARING WHO THE INSTRUCTION WAS FOR. THE RPTR ACKNOWLEDGED WITH HIS CALL SIGN BUT THE CTLR DID NOT CATCH THE READBACK.

Narrative: AT APPROX XA55 LCL TWR CLRED AN ACFT INTO POS AND HOLD ON RWY 28L AT PIT. WE WERE THE #1 ACFT IN LINE FOR RWY 28L. FLT NUMBER XXXX, WE ACKNOWLEDGE 'POS AND HOLD XXXX' AND PROCEEDED INTO POS ON RWY 28L. THE TWR THEN CLRED XXXA FOR TKOF RWY 28L, THE XXXA FLT ACKNOWLEDGE THE TKOF BUT STATED THERE WAS AN ACFT ON THE RWY. WE THEN NOTIFIED THE TWR THAT XXXX WAS ON THE RWY TWR THEN ORDERED US TO CLR AND XXXA INTO POS AND HOLD. THE XXXA FLT WAS ASKED WHAT HE HEARD HE STATED 'WE HEARD SOMEBODY CLRED INTO POS AND HOLD WE THOUGHT IT WAS US BUT WE WERE NOT #1 IN LINE.' THE XXXA THEN TOOK OFF WE WERE CLRED ON THE RWY FOR TKOF NO FURTHER SIT DEVELOPED. THIS WAS WELL INTO OUR 12 HR OF DUTY FOR THE DAY OR 7TH LEG AND ALREADY 6 HRS AND 40 MIN OF FLT TIME. THE WX CONDITIONS FOR THE DAY WERE LOW IMC AND HOLDING FOR APCHS WAS OCCURRING. AT THIS POINT IN TIME THE CREW'S FATIGUE FACTOR WAS HIGH AND THOUGHTS WERE ON THE OVERNIGHT AT CHO. IT IS APPARENT THAT A MISCOM OCCURRED THE XXXA FLT NEVER ACKNOWLEDGED POS AND HOLD WE DID. THE TWR DID NOT CATCH THE WRONG READBACK NOR THE ACFT ON THE RWY IN POS.

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.