Date: 201907
Local time of day: 1801-2400
Location: ZZZ.TRACON, US
Light: Dusk
Aircraft: Medium Large Transport
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Check Pilot; Captain
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Communication Breakdown; Fatigue; Confusion; Human-Machine Interface; Situational Awareness; Workload
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Contributing factors: Aircraft; Chart Or Publication; Human Factors
Primary problem: Chart Or Publication

Narrative: Cleared to descend via the STAR; Inbound to ZZZ we were cleared to fly runway XX transition prior to ZZZZZ intersection on the STAR. Speed was modified by ATC a number of times initially 290 kts for early to middle part of the STAR; then assigned as 210 kts or greater ZZZZZ1; I believe. This lead to some extra workload and verbalization to ensure we were in complying correctly and In agreement that we were flying. During this time the Approach Clearance was issued. As PF (Pilot Flying) I left the altitude alerter set at 6;000 MSL to allow the aircraft to capture the glide slope at 6;000 ft. ATC issued a clearance to fly a heading and descend to 3;000 followed quickly by clearance to descend to 2;000 MSL. I looked at the MCDU and noticed the 4;000 ft. published altitude. From the controllers tone; I had a feeling we could be high or were not set up properly although I could not find evidence at the time to support that. I initiated a 2;000 foot/minute descent. During this descent we the Captured the LOC and subsequently the glideslope. Uneventful approach and landing. After parking at the gate I noticed the tiny numbered notes for ZZZZZ2 and ZZZZZ3; 'MANDATORY at 4;000 ... and 3;000 ft.'. We were approaching ZZZZZ2 at 6;000 MSL when ATC issued the fly heading 310; descend and maintain 3;000; expedite descent'. We would not have been able to comply with ZZZZZ2 at 4;000 ft. had the ATC clearance not been issued. Abeam ZZZZZ3 we were at 3;000 ft. With dusk light and workload plus some tiredness it was difficult to see fine detail on the Approach Plate. The tiny; inconsequential note numbering makes it very difficult to see notations that are very untypical for approach plates. They need to be bigger and/or made more prominent. Blended STAR/Approach clearances are relatively new and are exposing new compliance threats such as this. Aircraft and all crew members are low time; inexperienced in aircraft and the nuances of VNAV set-up and unique compliance threats especially with a 'hidden'; too subtle note such as this.




Synopsis: Medium Large Transport Captain reported automation mismanagement resulting in undershooting altitude restrictions on approach.