C560XL crew experience a track deviation while departing sna on the MUSEL7 departure which is detect...

Narrative:

We departed sna on the musel 7 departure. We were initially cleared to 3000'. The musel 7 states that; upon reaching 1.0 DME from isna to turn left to 177 degrees for vectors to musel. Before 1.0 DME I armed the 'nav' mode to follow the flight director which was following FMS instructions. Both pilots had checked the FMS prior to flight and confirmed correct data for the departure and flight. At approximately 2000' I armed the autopilot and ATC instructed us to climb to 5000'. At 1.0 DME; the fligt director commanded a left turn and stopped on 177 degrees for a few seconds; as it was supposed to. The flight director then initiated a turn toward musel. The autopilot remained on. At approximately 4000' ATC inquired if we were on the musel 7 departure. We said 'yes.' they instructed that we were supposed to remain on 177 degrees and wait for them to vector us. ATC gave us a new heading; and we complied. While the FMS initially displayed the correct departure procedure. The flight director initiated a left turn to musel prior to the point desired by ATC. The SID chart should say 'expect' vectors; like it does in the enroute portion of sids; to draw attention to the fact that this heading needs to be maintained until instructed to do otherwise. Also; I believe honeywell should check the autopilot/FMS performance for this approach [departure].

Original NASA ASRS Text

Title: C560XL crew experience a track deviation while departing SNA on the MUSEL7 departure which is detected by SCT. The reportes believe the FMC malfunctioned taking the aircraft direct to MUSEL instead of maintaining a 177 degree heading for vectors.

Narrative: We departed SNA on the MUSEL 7 departure. We were initially cleared to 3000'. The MUSEL 7 states that; upon reaching 1.0 DME from ISNA to turn left to 177 degrees for vectors to MUSEL. Before 1.0 DME I armed the 'nav' mode to follow the flight director which was following FMS instructions. Both pilots had checked the FMS prior to flight and confirmed correct data for the departure and flight. At approximately 2000' I armed the autopilot and ATC instructed us to climb to 5000'. At 1.0 DME; the fligt director commanded a left turn and stopped on 177 degrees for a few seconds; as it was supposed to. The flight director then initiated a turn toward MUSEL. The autopilot remained on. At approximately 4000' ATC inquired if we were on the MUSEL 7 departure. We said 'Yes.' They instructed that we were supposed to remain on 177 degrees and wait for them to vector us. ATC gave us a new heading; and we complied. While the FMS initially displayed the correct departure procedure. the flight director initiated a left turn to MUSEL prior to the point desired by ATC. The SID chart should say 'EXPECT' vectors; like it does in the enroute portion of SIDs; to draw attention to the fact that this heading needs to be maintained until instructed to do otherwise. Also; I believe Honeywell should check the autopilot/FMS performance for this approach [departure].

Data retrieved from NASA's ASRS site 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	1232133
Time
Date	201501
Local Time Of Day	1201-1800
Place
Locale Reference	SNA.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Citation Excel (C560XL)
Operating Under FAR Part	Part 135
Flight Phase	Climb
Route In Use	SID MUSEL7
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying First Officer
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

C560XL crew experience a track deviation while departing sna on the MUSEL7 departure which is detected by sct. The reportes believe the FMC malfunctioned taking the aircraft direct to musel instead of maintaining a 177 degree heading for vectors.