EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Flight Crew Type 190
Human-Machine Interface; Situational Awareness
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance; Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Airspace Structure; Human Factors; Procedure
While performing the visual approach; I descended sooner than was prescribed on the approach chart. I descended to maintain 900 feet at 4 DME from the VOR instead of at 3 DME. Because of this I received both a GPWS 'TERRAIN' caution and a notification by ATC that we were too low. After our flight; the Captain and I debriefed the event and found that the 900 feet label is positioned rather close to the 4 DME label although it has an arrow pointing to the 3 DME label. Unable to look at the approach chart for too long because I was flying the aircraft; I quickly associated 900 feet with 4 DME instead of 3 DME and planned to descend to 900 feet earlier than I should have.Events like this can be prevented in the future by taking note of descent rate and angle while on the approach and calling out and verifying altitudes at specific fixes or distances while on the approach. The approach plate itself can also be altered by repositioning some of the altitude/distance labels to make things a little clearer and prevent possible confusion.
[Report narrative contained no additional information.]
The flight crew of an Embraer ERJ-175 reported that they descended too rapidly when they received a EPGWS obstacle alert and a call from Tower to say they were too low.