An emb-505 phenom pilot reported their aircraft turned to a fix on the SID 18 miles early.

Attributes
ACN	1578140
Time
Date	201809
Local Time Of Day	1201-1800
Place
Locale Reference	SJC.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	EMB-505 / Phenom 300
Flight Phase	Climb
Route In Use	SID SJC2
Flight Plan	IFR
Component
Aircraft Component	Navigational Equipment and Processing
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

Clearance was to do the SJC2 departure and after moony direct sjc. Programmed properly; verified by both pilots; and course line on map display showed proper course. Upon interception of course to moony; aircraft decided to turn direct sjc 18 miles early. The pilot monitoring notified pilot flying and ATC. ATC issued a new clearance and no further action was required. No suggestions; we caught the error and acted upon it. However the phenom has pulled tricks like this and others on our flight crews more than any other type aircraft I have flown in nearly 30 years of flying.

Original NASA ASRS Text

Title: An EMB-505 Phenom pilot reported their aircraft turned to a fix on the SID 18 miles early.

Narrative: Clearance was to do the SJC2 departure and after MOONY direct SJC. Programmed properly; verified by both pilots; and course line on map display showed proper course. Upon interception of course to MOONY; aircraft decided to turn direct SJC 18 miles early. The Pilot Monitoring notified Pilot Flying and ATC. ATC issued a new clearance and no further action was required. No suggestions; we caught the error and acted upon it. However the Phenom has pulled tricks like this and others on our flight crews more than any other type aircraft I have flown in nearly 30 years of flying.

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.