Gulfstream IV / G350 / G450
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 120; Flight Crew Total 9000; Flight Crew Type 800
Situational Awareness; Communication Breakdown
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Airspace Structure; Chart Or Publication; Human Factors
Prior to departure; the First Officer received a full route clearance over the radio. The clearance he wrote down was 'BASYE-SEALL-V188-GON-V374 INT ORW 130 degrees-DEEPO-ACK.' I checked this against FMS waypoints prior to engine start and was in agreement. In addition; BASYE is on the low altitude chart and it seemed a reasonable clearance as departing off Runway 16 at HPN on the WESTCHESTER3 heads the aircraft towards the area of BASYE.After takeoff and leveling at 11;000 MSL on a heading; we were cleared to BASYE/BAYYS. I prompted the FMS direct to 'BASYE' and engaged the LNAV. About a minute later Departure asked where we were going and I replied BASYE; phonetically spelling it out. He in return spelled out BAYYS to us. As I was entering this in the FMS; he gave us a turn to 150 degrees and handed us over to Boston Center. Just prior to the handoff; we were cleared direct to SEALL.Note: Both BASYE and BAYYS are depicted on the low altitude chart. BAYYS is located [East] of HPN (about 3 inches away on chart) while BASYE is located Northwest about 1.5 inches away. These closely spelled waypoints can lead to confusion. Some thought should be given to renaming one of them.
A G-IV flight crew--cleared to depart HPN via the WESTCHESTER SID; vector BAYYS on course--mistook 'BAYSE' for 'BAYYS' when cleared direct. ATC noted their error and provided corrective clearances.