Challenger 605
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Situational Awareness
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Clearance
Aircraft; Human Factors
After departing Runway 24; we were assigned the RUUDY departure. We climbed to 1;500 FT and leveled off. I engaged the autopilot. As they switched us over to Departure; the magenta VNAV altitude above the IVSI changed from 1;500 to 2;000 FT. Believing we had crossed the WENTZ Intersection; I dialed 2;000 FT in the altitude selector and selected VS; beginning a shallow climb for 2;000 FT. The pilot not flying stated 'we are not past WENTZ we need to stay at 1;500.' I rolled the VS wheel down to descend and disconnected the autopilot; descending back towards 1;500. We had climbed to 1;620 FT before descending. Operations continued as normal with no ATC interaction. Confirm VNAV altitudes above IVSI with way point passage in FMS.
CL605 First Officer reports leaving 1;500 FT for 2;000 FT prior to crossing WENTZ on the RUUDY 4 when the magenta VNAV altitude above the IVSI changed from 1;500 to 2;000. The pilot-not-flying Captain pointed out that WENTZ had had not yet been crossed.