BE35 pilot reports engaging the autopilot and GPS without verifying the waypoint after being cleared...

Attributes
ACN	1044392
Time
Date	201210
Local Time Of Day	1201-1800
Place
Locale Reference	RHV.Airport
State Reference	CA
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	Bonanza 35
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	GPS & Other Satellite Navigation
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine Flight Crew Commercial
Experience	Flight Crew Last 90 Days 15 Flight Crew Total 1550 Flight Crew Type 800
Events
Anomaly	Deviation - Procedural Clearance Deviation - Track / Heading All Types

Narrative:

Flight planned sjc vinco V107 pxn ... During IMC climb transition to level at 6;000 MSL; TRACON assigned a heading which was essentially direct vinco intersection. Nearing the intersection; I was cleared pilot navigation to join V107. I (too) quickly noted position on moving map display; and then engaged gpss and alt hold. As the aircraft began its turn; I turned to check the wings and tail for icing; as the aircraft was in cloud tops and temperature was slightly above freezing. A few moments later; I noted that the turn was continuing well beyond the expected heading; and immediately disengaged the autopilot while beginning a turn back toward the V107 course. Simultaneously; nct TRACON called to ask heading. I confirmed the turn on course and the controller noted that the heading had been almost the reciprocal of the expected heading. At this point; I recognized the problem. When I engaged gpss; the GPS had not yet sequenced from the sjc-vinco leg to the vinco-pxn (V107) leg. The GPS was attempting to reestablish itself on the first leg inbound to vinco; and gpss had commanded a near-360 turn. The correction is simple: before engaging the automation; ensure you know the state of the automation.

Original NASA ASRS Text

Title: BE35 pilot reports engaging the autopilot and GPS without verifying the waypoint after being cleared to join V107. The aircraft attempts to turn back to the previous fix (VOR) before it is detected by both ATC and the reporter.

Narrative: Flight planned SJC VINCO V107 PXN ... During IMC climb transition to level at 6;000 MSL; TRACON assigned a heading which was essentially direct VINCO Intersection. Nearing the intersection; I was cleared pilot navigation to join V107. I (too) quickly noted position on moving map display; and then engaged GPSS and alt hold. As the aircraft began its turn; I turned to check the wings and tail for icing; as the aircraft was in cloud tops and temperature was slightly above freezing. A few moments later; I noted that the turn was continuing well beyond the expected heading; and immediately disengaged the autopilot while beginning a turn back toward the V107 course. Simultaneously; NCT TRACON called to ask heading. I confirmed the turn on course and the Controller noted that the heading had been almost the reciprocal of the expected heading. At this point; I recognized the problem. When I engaged GPSS; the GPS had not yet sequenced from the SJC-VINCO leg to the VINCO-PXN (V107) leg. The GPS was attempting to reestablish itself on the first leg inbound to VINCO; and GPSS had commanded a near-360 turn. The correction is simple: before engaging the automation; ensure you know the state of the automation.

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.