Beech 1900
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Flight Crew Last 90 Days 150; Flight Crew Total 9300; Flight Crew Type 300
Situational Awareness
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
I was on recurrent pilot training flight for Part 135; conducting a multiple practice approaches in Point Magu airspace. On my last approach in Point Magu airspace we selected the LOC [for the] approach to OXR. After crossing final approach fix I descended on profile were we added additional practice on abnormal procedure to this approach for pilot training purpose. At intermediate point at OM (PARDS) there is altitude restriction of 1680 feet for localizer approach which I penetrated. I immediately started correcting; [a few seconds later] Oxnard tower gave low altitude warning which I confirmed; and stated that I [was] correcting.
BE1900 pilot reported descending below charted altitude on a practice approach to OXR airport.