Small Aircraft; Low Wing; 2 Eng; Retractable Gear
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 40; Flight Crew Total 7000; Flight Crew Type 2700
Confusion; Distraction; Situational Awareness
Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown; Ground Incursion Runway
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented
Human Factors; Airport; Chart Or Publication
In preparing for takeoff; we had been instructed to taxi to the run up area for Runways 14/20. In reviewing the airport chart again; that is also the A3 intersection. I had been told to expect Runway 14 for takeoff. The beginning of Runway 14 is north of the run up area. The beginning of Runway 20 is adjacent to the run up area. Both runways can be accessed from the A3 intersection; but not the full length of Runway 14. Taxiing to the beginning of runway 14 takes one across the approach path for runway 20. The signage is confusing. When told to continue my taxi to the hold short line; I missed the A3 intersection and proceeded north to the beginning of the runway. When I realized my error a moment later; I stopped and notified ground control. They told me to continue my taxi to the runway end but advised of a possible pilot deviation and requested I call the tower later.When I spoke to the tower later on the phone; I was told there was no safety issue since there was no traffic for Runway 20 and that; 'it was no big deal.' The controller told me that situation happens 2-3 times a day and they're documenting all instances in order to get the FAA to improve the signage. My takeaway is to be extra vigilant in studying the airport chart prior to taxi and have a clear picture of the route given in the instructions.
GA pilot reported incurring STS Runway 20 approach hold area after leaving the run up area. The reporter did not see the hold-short line protecting the Runway 20 approach path because of its distance from the Runway 14 entry taxiway.