Flight Crew Private; Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Commercial
Troubleshooting; Distraction; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Altitude Crossing Restriction Not Met; Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Aircraft Equipment Problem Dissipated; Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft
On VOR-A approach just short of the VOR passage at a 2800; VOR 1 DME became erroneous. This distracted us for a moment and PIC switched his screen to VOR/ILS system 2 to read correct DME. VOR2 DME seemed to be working. Because we were so close to station passage and the next step down altitude was after VOR passage; we descended to the next step down altitude too soon. When we left 2800 ft. the airport was in sight and was VMC. We were then aware that we descended early by a mile or two prior to the VOR and received a cautionary TAWS (Terrain Avoidance and Warning System) once but at that point we arrested the descent and adjusted the flight path and the alert had gone away and by then we had crossed the VOR and were at the altitude we were supposed to be at. The circle approach and landing were normal.10 minutes after landing DME 1 corrected itself and we contacted Maintenance control to let them know about DME 1and they informed us nothing was wrong with the plane.
[Report narrative contained no additional information.]
ATR 42-500 pilot crew reported the #1 DME was malfunctioning and receiving a CFTT alert.