Date: 201810
Local time of day: 0601-1200
Location: MMFR.ARTCC, FO
Flight conditions: VMC
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
ATC / advisory: Center MMFR
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Fatigue; Situational Awareness
Anomaly: ATC Issue All Types; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Returned To Clearance; Flight Crew Became Reoriented
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: [Ready to depart on] all-nighter [to MMMX]. As Captain I reviewed the airport pages at home as it has been over 6 months since I've flown into MMMX. Maintenance delay due to aircraft would not move during pushback...refused aircraft after 1 hour delay troubleshoot. Brought new aircraft from the hangar. I asked the First Officer (FO) if he was ok for flight; he said he was ok; I agreed; but we both talked about fatigue possibly being an issue later due to the delay. Aircraft was cleaned and departed the gate finally (3 hours and 34 minutes late). We briefed the flight at the gate and agreed the biggest threat would be fatigue and high altitude terrain. FO said he hadn't been to MMMX in over 3 months. Captain was pilot flying. Takeoff and cruise were uneventful; but both of us agreed fatigue was setting in. We both stayed caffeinated enroute and as the sun came up it seemed to wake us up a bit. During cruise we both reviewed all the 10-7; STAR and Approach pages and notes about the descent and speeds for the approach. We both looked at and reviewed the legs pages for the TIKEB 1C page and the ILS DME 2 RWY 05R. All legs and altitudes checked. Completed a further review and briefed the approach in entirety. Pilot Flying (PF) completed landing assessment due to high altitude airport. Weather was 2000 scattered to broken and another layer at about 8000 feet. MMFR center cleared us to descend via the TIKEB 1C and we started the descent on profile with 12;000 set in the altitude window. Center then cleared us direct to MAVEK which we entered in the legs page; confirmed and realized we were a little [high] on the profile due to the shortcut; so PF selected level change to ensure we got down in time to configure. Below FL200 and at 220 knots we lowered the flaps to 1 with speedbrakes extended to ensure meeting the altitude constraint (12;000 feet) at MAVEK. PF began slowing in the descent in order to configure at MAVEK. We switched to Approach [who] cleared us for the ILS DME 2 RWY 05R Approach. Controller asked us to maintain 200 knots for traffic behind us. The Pilot Monitoring (PM) told the Controller we needed to slow as per company policy and controller gave us 190 (this was a major distraction for both pilots)...at the time we were slower than that and PF put in 190 in the speed window...aircraft already in level change; lowered nose to gain speed back....Now cleared for the approach; PF set 7600 in the altitude window. Lowered the gear prior to MAVEK to begin configuring. Mistake was not reselecting VNAV. The descent continued and then PF felt uncomfortable with visual ground contact below/between the clouds. Checking the approach plate noticed MAVEK should have crossed at 12000...PF clicked autopilot off; left autothrottle on for speed protection; PF leveled off the aircraft immediately; just prior to MAVEK at 10000 feet. Aircraft was almost at MAVEK at level off so PF maintained current altitude and checked the approach plate for highest terrain and noticed we were still 2000 feet above the highest terrain on the approach chart. PM reset altitude to 9700 feet to again get back on descent profile after crossing MAVEK. We got back on profile; fully configured the flaps for landing and broke out underneath the clouds just past MEX05. We were configured at VREF+10 for the turn; armed the localizer and then glideslope captured both were stabilized and took over visually backed up with ILS with field in sight and VASIs prior to PLAZA. Uneventful landing and rollout. Approach never contacted us to check altitude; no other traffic was around and we received no radar altimeter or EGPWS alerts. #1 factor was fatigue due to 3 1/2 hour maintenance delay...Briefed at the gate as the biggest threat...and it was. #2 ATC asking to maintain speed when we wanted to configure to ensure a stable approach was a huge distraction to both pilots. [It] took attention away from altitude; which should have been the highest priority. #3 when cleared forthe approach should have ensured the FMC was in VNAV prior to selecting the lower approach altitude. Although not fatigued at the gate; both pilots knew it would be a factor and should have assessed the possibility of fatigue later (We took off after we should have already landed at MMMX). BIG lesson learned was to ensure selecting VNAV and checking in VNAV prior to selecting lowest approach altitude to ensure altitude constraints were met. I will incorporate this crosscheck every time just like execute/LNAV. PM did a great job assisting PF with flap configuration and altitude constraints after initial level off. Fatigue was definitely a factor and both the Captain and FO will submit fatigue reports.




Synopsis: B737 Captain reported overshooting an altitude restriction on approach into MMMX; citing fatigue as a factor.