Date: 201810
Local time of day: 0601-1200
Location: DEN.Airport, CO
Flight conditions: VMC
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B DEN
ATC / advisory: TRACON D01
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Situational Awareness
Second reporter function: Instructor; Pilot Not Flying; Check Pilot
Anomaly: ATC Issue All Types; Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: We briefed the RNAV RNP Z 16L into DEN. Conditions VFR. This was during IOE. Approach Control approved the RNAV RNP Z 16L Approach. Approach was installed and we were given direct to either KUURT or KIKME can't remember now which one; both fixes are part of the RNAV GPS Y 16L. Queried Controller and was given an intercept course to the final (between JOBOB (IAF) and LEETS). LEETS was the active waypoint and LNAV was armed; in HDG SEL at this time. Autopilot A in CMD. LNAV never captured and we went through the final approach course by maybe .5NM. Turned off the autopilot and manually re-intercepted the final. Normal and stable approach from that point until touch down.


Second narrative: On arrival to DEN. I was conducting Captain (CA) Operating Experience (OE) and had requested the RNAV (RNP) Z 16L Approach from ATC. I was hoping to have the CA get more experience conducting non precision approaches. DEN ATC had acknowledged my request for the RNAV (RNP) Z 16L and told us to expect vectors to intercept the final approach course. ATC had given us a heading of 190 to intercept the final approach course for RWY 16L. So far all was well. Weather conditions at the time were good VFR with visibilities greater than 10 miles and a high scattered layer of clouds. The CA OE student had configured with Flaps 5 and speed was assigned at 180 or 170; I can't remember exactly. At any rate; DEN ATC assigned us heading 190 to intercept final approach course and 8;000 feet until KIKME and cleared us for the RNAV Approach to RWY 16L. I was confused for a moment because we had asked for and been told to expect the RNAV Z 16L and that approach does not have KIKME intersection on it. The RNAV Y 16L does have KIKME intersection on it. I asked ATC if they meant LEETS intersection....LEETS is the FAF on the RNAV (RNP) Z 16L and I was expecting to hear that intersection. ATC responded and said sure; just maintain 7;000 until LEETS 190 on the heading and intercept the final approach course cleared for the approach. I read all that back and watched the OE CA arm the LNAV and the VNAV so that the autopilot would fly the initial portion of the approach. The autopilot proceeded to fly on the 190 heading right through the final approach course and start to infringe on the final approach course for RWY 16R. Both of us saw this happen and the OE CA disconnected the autopilot and hand flew the aircraft back to the left to rejoin the final approach course for RWY 16L. At the same time DEN ATC asks us if we are joining the final approach course for 16L. We acknowledged that we had accidentally flown through the final approach course for our assigned runway and were correcting back. ATC pointed out traffic that was ahead of us and flying to the parallel runway....we saw that aircraft and informed ATC that we had the preceding aircraft in sight; we were correcting back to the assigned runway final approach course. We never received a TCAS RA or TA regarding the aircraft ahead of us and landing the parallel runway.


Synopsis: B737 flight crew reported a track deviation occurred on the RNAV (RNP) Z 16L Approach to DEN.