Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 4982
Troubleshooting; Situational Awareness; Confusion
Conflict Airborne Conflict; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Aircraft; Human Factors
We were cleared for the Stadium Visual Approach to Runway 29 at EWR; with the RNAV (RNP) Y 29 loaded in the FMC as an [overlay] and the autopilot engaged. Clearance was to maintain 3000 ft until TEB; cleared for the approach. At about 2 nm from TEB; we set touchdown zone elevation of 100 ft in the MCP altitude window. We had a short discussion whether setting the altitude was too early. At about 1 NM from TEB the aircraft started down. I disconnected the autopilot at 2800 ft and was correcting back to 3000 ft at 2700 ft. In an effort to be smooth; I was not aggressive enough in getting back to 3000 ft.  We then received TCAS RA while correcting back to 3000 ft. I attempted to confirm the approach and re-engage the autopilot. The aircraft started down again and was not on the approach track. I do not believe at this point I was in LNAV and because of the MCP altitude; we went low again; I disconnected the autopilot and flew the approach. It was around this time Newark Tower informed us of a Low Altitude Alert and I made a correction. When the PAPI for Runway 29 came into view; we were on profile.
[Report narrative contained no additional information.]
Air carrier flight crew reported the autopilot descended too early while on the EWR Runway 29 Stadium Visual resulting in an RA.