Narrative:

Ground: prior to departing sdl; we briefed the banyo 4 SID chart; which was assigned by ATC as part of the departure clearance. This SID was briefed twice; once after receiving the ATC clearance from the tower and once again after receiving the same clearance from phx approach as part of a 'void time release' (tower had closed). Flight: I flew the departure in FMS 'blue data' with LNAV selected for lateral guidance. Per the SID; I turned right to a heading of 300 degrees with the intent of intercepting the radial from pxr to banyo. Shortly after reaching a heading of 300 degrees; ATC issued instructions to turn left to a heading (I believe heading 290 degrees) and intercept the pxr 321 degree radial. A turn was initiated. At this point; I thought the controller was turning us west to initiate an earlier intercept of the SID course from pxr to banyo. After turning to the assigned heading; I then turned the plane north to intercept the assigned SID course from pxr to banyo thinking that this course was on the pxr 321 degree radial (it's actually on the pxr 336 degree radial). We remained on course to banyo for a very short time and were then issued another heading (I think 270 degrees this time) to intercept the pxr 321 degree radial. At this point; I knew that we weren't flying the course that the controller was requesting. I complied with the turn to the assigned heading and stayed in heading mode until the other pilot made the changes to the FMS to set up our intercept of the pxr 321 degree radial. Upon reaching the pxr 321 degree radial; we intercepted the 321 degree course to zeper. At no time did we receive any urgent requests from the controller for immediate course changes nor did we get any TCAS warnings or advisories. When we were handed off to phoenix center; we were given a phone number to call to discuss a possible pilot deviation. Note: after reporting this event to my chief pilot; he contacted a supervisor and a safety officer at the phoenix ATC. He learned that the design of the banyo 4 departure conflicts with the phoenix traffic flow and; therefore; vectors on the SID departure out of scottsdale are issued routinely. This has caused issues in the past and the problems continue even today. He was also told that a change in the design of the departure may be in the works. A heads up to the pilots departing on the SID that vectors are often given in lieu of the published course as a note would go a long way toward preventing this from occurring in the future. This could be in the form of attaching to the departure clearance that there exists the possibility that a turn to intercept a different radial than the 336 degrees to banyo may be requested. The flight crews would then be prepared for the alternate navigation procedure. Contributing factors: 1) this was a night departure in a mountainous area from a closed tower airport. The SID routing was carefully briefed and to a degree 'burned into' our minds to be sure we understood exactly what the routing required and how we would navigate the requested route. 2) neither pilot flies to or from sdl on a regular basis. There was no way to know from the published charts; ATIS or verbal clearance that we should expect anything other than the assigned banyo 4 SID. We didn't know that actual routing of aircraft departing sdl regularly deviated from the SID routing to assigned radials not already loaded into the FMS for quick reference or retrieval. The early vector off the SID routing came to us as an unexpected change that was not easily recognized or remedied by the pilots. Sort of a 'curve ball.' 3) even minor changes or additions; such as including the name of the fix; the controller wanted us to fly the 321 degree radial to (i.e.; zeper versus banyo); to our departure or subsequent clearances would have made the controller's wishes much clearer to us and undoubtedly changed our response to the controller's request.

Related reports:

Google
 

Original NASA ASRS Text

Title: G450 flight crew is cleared and briefed the BANYO4 departing SDL. Once airborne on the 300 degree heading Controller issues 290 degree heading to intercept PXR 321 degree radial. The crew does not comprehend that this radial is different from the SID radial causing an early turn and a track deviation.

Narrative: Ground: Prior to departing SDL; we briefed the BANYO 4 SID chart; which was assigned by ATC as part of the departure clearance. This SID was briefed twice; once after receiving the ATC clearance from the Tower and once again after receiving the same clearance from PHX Approach as part of a 'void time release' (Tower had closed). Flight: I flew the departure in FMS 'blue data' with LNAV selected for lateral guidance. Per the SID; I turned right to a heading of 300 degrees with the intent of intercepting the radial from PXR to BANYO. Shortly after reaching a heading of 300 degrees; ATC issued instructions to turn left to a heading (I believe heading 290 degrees) and intercept the PXR 321 degree radial. A turn was initiated. At this point; I thought the Controller was turning us west to initiate an earlier intercept of the SID course from PXR to BANYO. After turning to the assigned heading; I then turned the plane north to intercept the assigned SID course from PXR to BANYO thinking that this course was on the PXR 321 degree radial (it's actually on the PXR 336 degree radial). We remained on course to BANYO for a very short time and were then issued another heading (I think 270 degrees this time) to intercept the PXR 321 degree radial. At this point; I knew that we weren't flying the course that the Controller was requesting. I complied with the turn to the assigned heading and stayed in heading mode until the other pilot made the changes to the FMS to set up our intercept of the PXR 321 degree radial. Upon reaching the PXR 321 degree radial; we intercepted the 321 degree course to ZEPER. At no time did we receive any urgent requests from the Controller for immediate course changes nor did we get any TCAS warnings or advisories. When we were handed off to Phoenix Center; we were given a phone number to call to discuss a possible pilot deviation. Note: After reporting this event to my Chief Pilot; he contacted a Supervisor and a Safety Officer at the Phoenix ATC. He learned that the design of the BANYO 4 Departure conflicts with the Phoenix traffic flow and; therefore; vectors on the SID departure out of Scottsdale are issued routinely. This has caused issues in the past and the problems continue even today. He was also told that a change in the design of the departure may be in the works. A heads up to the pilots departing on the SID that vectors are often given in lieu of the published course as a note would go a long way toward preventing this from occurring in the future. This could be in the form of attaching to the departure clearance that there exists the possibility that a turn to intercept a different radial than the 336 degrees to BANYO may be requested. The flight crews would then be prepared for the alternate navigation procedure. Contributing factors: 1) This was a night departure in a mountainous area from a closed tower airport. The SID routing was carefully briefed and to a degree 'burned into' our minds to be sure we understood exactly what the routing required and how we would navigate the requested route. 2) Neither pilot flies to or from SDL on a regular basis. There was no way to know from the published charts; ATIS or verbal clearance that we should expect anything other than the assigned BANYO 4 SID. We didn't know that actual routing of aircraft departing SDL regularly deviated from the SID routing to assigned radials not already loaded into the FMS for quick reference or retrieval. The early vector off the SID routing came to us as an unexpected change that was not easily recognized or remedied by the pilots. Sort of a 'curve ball.' 3) Even minor changes or additions; such as including the name of the fix; the Controller wanted us to fly the 321 degree radial to (i.e.; ZEPER versus BANYO); to our departure or subsequent clearances would have made the Controller's wishes much clearer to us and undoubtedly changed our response to the Controller's request.

Data retrieved from NASA's ASRS site as of April 2012 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.