Air carrier first officer reported a track deviation occurred on arrival into den following multiple...

Narrative:

[Our international flight to] den was running about 1 hr+ late. Flight is manned as a 3 man crew and fatigue was noticeable on all of us with only a 2hr 40 min break each. We received 3 different arrivals and the last one was moltn 3 RNAV arrival. We planned and briefed the 34R ILS. It was windy conditions but VFR and field was in sight around 13000 feet. In the descent sometime after ramms we were told to expect RNAV (rnp) Z 34R. Several speed assignments were given by approach different than published on the arrival. I was the pilot flying (PF) and was busy complying with speed and altitude crossings so the pilot monitoring (pm) programmed the FMC. Pm entered the required entries and we quickly briefed the RNAV (rnp) Z runway 34R approach. Unfortunately; we missed that the legs pages wasn't sequenced correctly. The nd displayed the RNAV arc with restrictions but a discontinuity was apparently left from moltn 3 on page one. We were cleared for the approach near babaa. When we crossed himom the airplane didn't start down as anticipated. I manually started down and within seconds we crossed mcmul. Now the airplane doesn't start the expected turn to follow the arc. At this time I disconnected the autopilot and was flying manually to the kugln and basyn fixes. What seemed like an easy approach deteriorated quickly. We were now in heading mode on the MCP instead of LNAV as required. Because of the good weather we decided to continue the approach hand flown and intercept the final visually with approach mode armed. The final was intercepted and approach mode and glidepath were captured. Once on final the approach and landing was uneventful. Contributing factors: fatigue; last minute changes to arrivals; speed; altitudes; and the anticipated approach. Busy environment for PF and pm and correct sequencing was missed. High altitude airport. Visibility was good and outside references made us complacent inside. Neither of us had flown this route recently and got caught with an unexpected approach [that was different from what was] advertised on ATIS.

Original NASA ASRS Text

Title: Air carrier First Officer reported a track deviation occurred on arrival into DEN following multiple ATC changes to the arrival clearance. Fatigue was cited as a contributing factor.

Narrative: [Our international flight to] DEN was running about 1 hr+ late. Flight is manned as a 3 man crew and fatigue was noticeable on all of us with only a 2hr 40 min break each. We received 3 different arrivals and the last one was MOLTN 3 RNAV Arrival. We planned and briefed the 34R ILS. It was windy conditions but VFR and field was in sight around 13000 feet. In the descent sometime after RAMMS we were told to expect RNAV (RNP) Z 34R. Several speed assignments were given by approach different than published on the arrival. I was the Pilot Flying (PF) and was busy complying with speed and altitude crossings so the Pilot Monitoring (PM) programmed the FMC. PM entered the required entries and we quickly briefed the RNAV (RNP) Z RWY 34R approach. Unfortunately; we missed that the legs pages wasn't sequenced correctly. The ND displayed the RNAV arc with restrictions but a discontinuity was apparently left from MOLTN 3 on page one. We were cleared for the approach near BABAA. When we crossed HIMOM the airplane didn't start down as anticipated. I manually started down and within seconds we crossed MCMUL. Now the airplane doesn't start the expected turn to follow the arc. At this time I disconnected the autopilot and was flying manually to the KUGLN and BASYN fixes. What seemed like an easy approach deteriorated quickly. We were now in Heading Mode on the MCP instead of LNAV as required. Because of the good weather we decided to continue the approach hand flown and intercept the final visually with Approach Mode armed. The final was intercepted and Approach Mode and Glidepath were captured. Once on final the approach and landing was uneventful. Contributing factors: Fatigue; last minute changes to arrivals; speed; altitudes; and the anticipated approach. Busy environment for PF and PM and correct sequencing was missed. High altitude airport. Visibility was good and outside references made us complacent inside. Neither of us had flown this route recently and got caught with an unexpected approach [that was different from what was] advertised on ATIS.

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.

Attributes
ACN	1555874
Time
Date	201806
Local Time Of Day	1201-1800
Place
Locale Reference	DEN.Airport
State Reference	CO
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Boeing Company Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Total 10583 Flight Crew Type 639
Events
Anomaly	Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Air carrier first officer reported a track deviation occurred on arrival into den following multiple ATC changes to the arrival clearance. Fatigue was cited as a contributing factor.