Any Unknown or Unlisted Aircraft Manufacturer
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Confusion; Communication Breakdown; Situational Awareness
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Returned To Clearance
Human Factors
Flying Pilot thought he was cleared for visual approach.ATC then gave us a low altitude warning and instructed us to climb back up to 3;000 feet.During descent the Flying Pilot asked the Monitoring Pilot to ask the ATC Controller how to cancel our IFR flight plan. The Controller then gave the Pilot Monitoring instructions on how to cancel our IFR flight plan. Upon hearing this; the Flying Pilot mistook it for cleared for a visual approach. The altitude alerter was then changed and no communication was exchanged to the other Pilot about the change.We complied with instructions.Suggestions - Verify you heard what you thought you heard. Always keep other Pilot informed of altitude change in altitude alerter if self changed or have the other Pilot change it.
During descent; Controller went over canceling procedures. Pilot thought we were cleared for approach. Altitude was changed without confirmation and was told to climb back up. Lesson learned.In approach mode; confusing instructions; did not verify altitude. Lesson learned.
Pilot reported ATC low altitude alert on approach to JZI airport.