Anchorage center took exception to what they considered an early turn by a learjet flying the obstac...

Attributes
ACN	960763
Time
Date	201107
Local Time Of Day	1201-1800
Place
Locale Reference	ZAN.ARTCC
State Reference	AK
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Learjet 31
Operating Under FAR Part	Part 135
Flight Phase	Climb
Route In Use	Other Obstacle DP
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 60 Flight Crew Total 5700 Flight Crew Type 60
Person 2
Function	Pilot Not Flying Captain
Qualification	Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 80 Flight Crew Total 5000 Flight Crew Type 2200
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

We departed pawg on the obstacle departure procedure toward lvd VOR. Our next waypoint was yyj; which was approximately a 140 degree turn to the left. After accelerating above 10;000 ft (we had been cleared to FL280); our FMS commanded a predictive turn toward yyj before crossing lvd. During the turn; we selected direct yyj; which centered our course needle and our turn radius decreased. Some time after this; anchorage center established radar contact with us and asked us if we had crossed the lvd VOR on our departure. We explained the FMS predictive turn but the controller implied that we had made a lateral navigation error. We were not informed of any pilot deviation nor given a phone number to contact during or after the flight. At no time was obstacle clearance an issue for us; but we felt that we didn't want to cause any confusion with the controlling facility. In the future; we will fly this procedure using short range navigation source (raw data) to prevent having our waypoint dropped by the FMS and turning early as it anticipates the course change. We will also avoid using the direct command on the FMS; as the resulting course line may be shifted from what ATC is expecting to see.

Original NASA ASRS Text

Title: Anchorage Center took exception to what they considered an early turn by a Learjet flying the obstacle clearance departure procedure from PAWG to LVD VOR; thence on course to YYJ VOR.

Narrative: We departed PAWG on the obstacle departure procedure toward LVD VOR. Our next waypoint was YYJ; which was approximately a 140 degree turn to the left. After accelerating above 10;000 FT (we had been cleared to FL280); our FMS commanded a predictive turn toward YYJ before crossing LVD. During the turn; we selected direct YYJ; which centered our course needle and our turn radius decreased. Some time after this; Anchorage Center established radar contact with us and asked us if we had crossed the LVD VOR on our departure. We explained the FMS predictive turn but the Controller implied that we had made a lateral navigation error. We were not informed of any pilot deviation nor given a phone number to contact during or after the flight. At no time was obstacle clearance an issue for us; but we felt that we didn't want to cause any confusion with the controlling facility. In the future; we will fly this procedure using short range navigation source (raw data) to prevent having our waypoint dropped by the FMS and turning early as it anticipates the course change. We will also avoid using the direct command on the FMS; as the resulting course line may be shifted from what ATC is expecting to see.

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.

Anchorage center took exception to what they considered an early turn by a learjet flying the obstacle clearance departure procedure from pawg to lvd VOR; thence on course to yyj VOR.