B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Type 285
Distraction; Human-Machine Interface; Situational Awareness; Time Pressure
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors; Procedure
Prior to descent the RNAV (RNPZ) for Runway 35R was briefed and programmed into the FMC as the expected clearance. We discussed as a crew both options of 1) connecting the arrival and approach prior to actual clearance; creating the threat of a turn without clearance; or 2) leaving a discontinuity in the FMC which would be closed once clearance was received. During the arrival we received numerous speed changes and a relatively late clearance for the approach. As Pilot Flying (PF) I asked the Pilot Monitoring (PM) to close the discontinuity. I observed him working in the box and verified the change. Though I verified the change I was distracted with managing an assigned speed change and aircraft configuration and did not recognize that the FMC was not correctly sequenced. [A crosscheck] was performed and all appeared correct as the FMAs for the arrival presented the same as they would for the approach (LNAV/VNAV PATH and a centered path indication on the ND). Upon arriving at the point beginning the RF leg the aircraft did not begin its turn and the FMC error became apparent. ATC queried us regarding our course and subsequently vectored us off the approach.
B737 First Officer reported a track deviation occurred on the RNAV (RNP) Z Approach to DEN after a late clearance and failing to catch a discontinuity in the briefing.