Small Transport
Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Commercial; Flight Crew Multiengine
Flight Crew Last 90 Days 200; Flight Crew Total 2100; Flight Crew Type 500
Confusion; Situational Awareness
Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway; Ground Incursion Taxiway
Flight Crew Became Reoriented
Human Factors; Airport
This was a two pilot flight. We had a current paper taxi diagram out as well as a taxi diagram on the MFD of the plane. We were taxiing out of [the] FBO. We called Farmingdale Ground to taxi. They told us to taxi Golf and cross a runway. The taxi signs made it look like we were already on Golf and we crossed 1/19. What we didn't know at the time was that we went out G5 and crossed 1/19. When we were supposed to taxi south on Taxiway Golf and cross 14/32. We didn't see this because we were at [the FBO] facing north. Taxiway Golf was actually behind us. We notified Ground of our mistake. They gave us new taxi instructions. When we spoke with them over the phone they said what we did was a common event. People mistake G5 taxiway and Taxiway Golf often.
Corporate Captain reported taxiing onto wrong taxiway and incurred onto runway due to poor airport signage.