Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Flight Crew Commercial; Flight Crew Flight Instructor
Flight Crew Last 90 Days 50; Flight Crew Total 1250; Flight Crew Type 600
Communication Breakdown; Confusion; Distraction; Workload
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance; Flight Crew Took Evasive Action
Environment - Non Weather Related; Human Factors
Center cleared us for the ILS 18L approach at MDH and told us to maintain 3;000 FT until established. It was the first IFR cross country for my student; and it was a very high workload flight for me to try to teach; watch over what the student was doing; help them set up for the instrument approach and understand what they needed to do; and there had been lots of other traffic throughout the flight. As we were flying towards CABBI intersection (the outer marker for the ILS) I looked down at my approach plate and at the radio to check what my student had started a descent down to 2;200 [FT] because he was apparently confused. I caught him and told him to go back to 3;000 [FT]; but as I did that Center yelled at us for being at 2;700 [FT] when we weren't established on the approach. We immediately climbed back.
An Instrument Instructor reported his IFR student began a descent to the final approach altitude early and was warned by ATC to return to the cleared altitude.