A g-iv flight crew--cleared to depart hpn via the westchester SID; vector bayys on course--mistook '...

Narrative:

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.

Original NASA ASRS Text

Title: 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.

Narrative: 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.

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.

Attributes
ACN	1035683
Time
Date	201209
Local Time Of Day	0601-1200
Place
Locale Reference	HPN.Airport
State Reference	NY
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Gulfstream IV / G350 / G450
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 120 Flight Crew Total 9000 Flight Crew Type 800
Events
Anomaly	Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance Deviation - Track / Heading All Types

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.