Light Transport; Low Wing; 2 Turbojet Eng
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Distraction
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Flight Crew Became Reoriented
Human Factors
CSG was VFR and I requested an RNAV GPS 24 for practice.  I used CDFA procedures; which we briefed. At 3;000 feet; armed VNAV and set DDA to 1;090 feet (940+100 high mins + 50=1090.) Set AAD to 1;100 feet.  FO was talking to CSG traffic and approach and I got distracted with my iPad which I had accidentally put on freeze on airport page.  We got 'Terrain; Terrain' warning and I noticed we were at about 1;700 feet and descending. I added power and climbed up to the VASI slope. Landed plane normally.Not to let guard down in visual conditions and fly the plane. Watch out for distractions. Cross check instruments and not rely on automation completely.
Corporate jet pilot reported a CFTT event during approach to CSG.