Narrative:

I had 2 [of the same aircraft type] holding short of runway 14; one at taxiway a and the other in the run-up area. Aircraft X called ready to go as aircraft Y crossed over the hold short line at 'a' and proceeded onto the runway. I thought the aircraft that called was the one moving and asked if he was already on the runway. Then aircraft Y on the runway called ready to depart as he taxied down runway 14 to runway 19. I told aircraft Y to cross runway 14 back to run-up area and contact ground for a possible pilot deviation. The taxiway markings and runway signs at the field are very confusing and lead to many mistakes. I do not know if that would have stopped this incident; but better signage would certainly help to avoid mistakes by pilots not familiar with this airport.

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Original NASA ASRS Text

Title: Two STS controllers report a Runway 14 incursion at Taxiway A because of poor taxiway and runway signage.

Narrative: I had 2 [of the same aircraft type] holding short of Runway 14; one at Taxiway A and the other in the run-up area. Aircraft X called ready to go as aircraft Y crossed over the hold short line at 'A' and proceeded onto the runway. I thought the aircraft that called was the one moving and asked if he was already on the runway. Then aircraft Y on the runway called ready to depart as he taxied down Runway 14 to Runway 19. I told aircraft Y to cross Runway 14 back to run-up area and contact Ground for a possible pilot deviation. The taxiway markings and runway signs at the field are very confusing and lead to many mistakes. I do not know if that would have stopped this incident; but better signage would certainly help to avoid mistakes by pilots not familiar with this airport.

Data retrieved from NASA's ASRS site as of July 2013 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.