Narrative:

While taxiing out of sat; we were given taxi instructions to proceed on runway 4 to runway 31L. Upon reaching 31L; my focus was on the runway pavement of runway 4 to look for the hold short marks to be sure that we did not cross them. After looking for the marks for several seconds; it became apparent to us that we had already crossed them and had entered runway 31L. We immediately notified the ground controller of what had happened and what action we needed to take.at this time; we were instructed to cross runway 31L; and make a 180 degree turn back to runway 31L. It was at this time that we noticed the hold short markings were almost completely worn off or covered with tire residue due to being in the touchdown zone of runway 4 and were not visible. Especially with the sun in the position that it was in at the time of the event.

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Original NASA ASRS Text

Title: Corporate Captain reported a runway incursion at SAT; and attributed this event to the invisible hold short markings on the surface.

Narrative: While taxiing out of SAT; we were given taxi instructions to proceed on runway 4 to runway 31L. Upon reaching 31L; my focus was on the runway pavement of runway 4 to look for the hold short marks to be sure that we did not cross them. After looking for the marks for several seconds; it became apparent to us that we had already crossed them and had entered runway 31L. We immediately notified the ground controller of what had happened and what action we needed to take.At this time; we were instructed to cross runway 31L; and make a 180 degree turn back to runway 31L. It was at this time that we noticed the hold short markings were almost completely worn off or covered with tire residue due to being in the touchdown zone of runway 4 and were not visible. Especially with the sun in the position that it was in at the time of the event.

Data retrieved from NASA's ASRS site 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.