Date: 201809
Local time of day: 1201-1800
Location: SNA.Airport, CA
Flight conditions: Mixed
Weather elements / visibility: 9
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class C SNA
ATC / advisory: TRACON SCT
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Workload; Time Pressure; Situational Awareness
Second reporter function: Pilot Flying; First Officer
Anomaly: 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: Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Human Factors; Aircraft
Primary problem: Human Factors

Narrative: We were on the final portion of OHSEA 1 Arrival into SNA and checked in with Final Controller; he did not assign an approach; visual or RNAV; since ILS was NOTAMed out. I asked for the RNAV (RNP) Z Runway 20R; and he said no problem. We were just a couple miles west of KLEVR fix which begins the RNAV. The controller cleared us for the requested approach and First Officer (Pilot Flying) tried to close the discontinuity and add MNNIE to continue the procedure. I was clearing outside and took quick glances as he could not close the DISCON. By the time I looked inside to check; SoCal asked if we were having trouble because we were not intercepting the track for the approach. This all happened in the matter of a minute it seemed. I then requested the visual approach to 20R instead. I told the First Officer not to worry about why he couldn't close the DISCON at that point and we'd sort it out on the ground. We received two heading vectors to the final and the remainder of the approach was unremarkable. Before the controller switched us to the Tower; he made the comment that he noticed several Company flights had had the same problem at the same fix (KLEVR) as we showed. He said 'no problem; just curious' and switched us. And that's why we're submitting ASAPs! DISCONs happen from time to time; especially with rushed clearances and compression like we had. I could've maybe coordinated a little quicker with SoCal and asked for the visual to prevent the track divergence.


Second narrative: We were descending via the OHSEA1 arrival into KSNA for runway 20R. The ILS was NOTAMed out of service. Upon check-in with the Final Approach Controller; just prior to KLEVR and at 5;000 feet MSL; we requested and were cleared for the RNAV (RNP) Z Runway 20R. I selected the RNAV Z 20R on the DEP/ARR page on the FMC then went to the LEGS page to attempt to fix the discontinuity. I was unable to get the FMC to accept bringing the next point on the RNAV Z; MNNIE; to its proper sequence after KLEVR. We got an LNAV disconnect as we passed KLEVR; and the autopilot went into CWS-R. I started a turn toward the proper course; but by that time we were probably half a mile off course; and the Controller asked why we were off course. He said that this was the second time that day that a Company Crew had made the same error. We asked for vectors to the visual; and proceeded to an uneventful landing.


Synopsis: B737-700 flight crew reported a track deviation occurred on the RNAV (RNP) Z Approach to 20R in SNA when the First Officer failed to close a discontinuity.