EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Confusion; Situational Awareness; Human-Machine Interface
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Chart Or Publication; Human Factors; Procedure
While on descent to Nashville on the SWFFT ONE RNAV STAR and descending from the ADAAY Intersection to the CORRA Intersection I misread the crossing restriction as 4;000 FT and not 6;000 FT at CORRA. I appear to have looked at the crossing restriction at the ONUGE Intersection rather than that at CORRA. I realized this mistake as we descended through 5;000 FT when I rechecked the plate for the next altitude on the descent. I immediately changed the descent into a climb somewhere between 4;700-4;800 FT MSL. ATC called to check the altitude a few moments later. ATC then assigned an altitude of 5;000 FT for the remainder of that section of the descent. The Controller did not seem perturbed or overly concerned. This was the first flight into Nashville and additionally the first use of this STAR for my First Officer. Indeed the plate is only 30 days old after it's initial issue. Contributing factors are an overly information saturated approach plate that I feel should be spread out over a bi-fold approach plate as is common on other STAR plates. The ONUGE information bubble is twice the size and more prominent in placement just below the CORRA Intersection. This bubble overshadows the smaller CORRA bubble that is placed off to the left of the plate and is half the size. Task saturation in the VFR environment of a busy airport and my unfamiliarity with the location of the airport and landing runways added to my workload of interpreting the plate on this arrival while looking for VFR traffic and the location of the airport.
An EMB-145 flight crew misread the 6;000 MSL crossing restriction at CORRA on the SWFFT RNAV STAR to BNA and descended more than a thousand feet below until queried and reassigned 5;000 by Approach Control. The reporter cited the saturation and complexity of the STAR chart as a contributing factor.