Narrative:

I was on an IFR training flight with an advanced student pilot, the purpose of the flight was to track direct from msn to dll at total distance of approximately 30 mi. After departing and climbing to approximately 4000' we went IMC and broke out at approximately 4800 MSL. We then continued to climb to 6000'. We were turned over from madison departure to chicago center 133.6. Chicago then cleared us to 3300' where we broke out of the bottom layer. Chicago center then proceeded to give us our missed approach procedures which I repeated correctly. My student, however, became confused and I then began to explain to him the instructions. The VOR a approach into dll has lower minimums if you receive dells altimeter settings so I proceeded to show my student how to talk to the dells on 122.8 on communication 2 while listening on 133.6. We received the altimeter setting and I turned communication 1 back on. But I was unaware that my student had turned communication 1 volume down to an unreadable level so he could hear me. We proceeded to cross to VOR and my student became very disoriented and began to proceed on the following pattern instead of published. I then began to tell the student to proceed direct to the VOR and wait for the approach clearance since we were in VFR conditions. After passing over the top of the airport at assigned altitude, I called approach and he realized that the radio had been turned down. I was then verbally advised by the controller seriously shaking up my student. I explained that we had radio failure. He said I've been trying to reach you for 5 minutes, and did I know the correct procedure for radio failure. He asked is there an instructor on board, I answered yes. And did we know we were 90 degree off heading. My student had become so shaken that he could no longer fly. I then proceeded to take command of the flight and direct msn which was uneventful. First I was unaware that radio failure had occurred and so did not go through the radio failure procedures according to para 471 of the aim. The student was so upset that he could no longer hold heading or even fly. My students can no longer touch the radios without my permission.

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Original NASA ASRS Text

Title: CFII AND STUDENT HAVE TRACK DEVIATION AS WELL AS LOST COM WITH ZAU DUE TO STUDENT'S HAVING TURNED DOWN RADIO VOLUME IN ORDER TO HEAR INSTRUCTOR.

Narrative: I WAS ON AN IFR TRAINING FLT WITH AN ADVANCED STUDENT PLT, THE PURPOSE OF THE FLT WAS TO TRACK DIRECT FROM MSN TO DLL AT TOTAL DISTANCE OF APPROX 30 MI. AFTER DEPARTING AND CLIMBING TO APPROX 4000' WE WENT IMC AND BROKE OUT AT APPROX 4800 MSL. WE THEN CONTINUED TO CLIMB TO 6000'. WE WERE TURNED OVER FROM MADISON DEP TO CHICAGO CENTER 133.6. CHICAGO THEN CLRED US TO 3300' WHERE WE BROKE OUT OF THE BOTTOM LAYER. CHICAGO CENTER THEN PROCEEDED TO GIVE US OUR MISSED APCH PROCS WHICH I REPEATED CORRECTLY. MY STUDENT, HOWEVER, BECAME CONFUSED AND I THEN BEGAN TO EXPLAIN TO HIM THE INSTRUCTIONS. THE VOR A APCH INTO DLL HAS LOWER MINIMUMS IF YOU RECEIVE DELLS ALTIMETER SETTINGS SO I PROCEEDED TO SHOW MY STUDENT HOW TO TALK TO THE DELLS ON 122.8 ON COM 2 WHILE LISTENING ON 133.6. WE RECEIVED THE ALTIMETER SETTING AND I TURNED COM 1 BACK ON. BUT I WAS UNAWARE THAT MY STUDENT HAD TURNED COM 1 VOLUME DOWN TO AN UNREADABLE LEVEL SO HE COULD HEAR ME. WE PROCEEDED TO CROSS TO VOR AND MY STUDENT BECAME VERY DISORIENTED AND BEGAN TO PROCEED ON THE FOLLOWING PATTERN INSTEAD OF PUBLISHED. I THEN BEGAN TO TELL THE STUDENT TO PROCEED DIRECT TO THE VOR AND WAIT FOR THE APCH CLRNC SINCE WE WERE IN VFR CONDITIONS. AFTER PASSING OVER THE TOP OF THE ARPT AT ASSIGNED ALT, I CALLED APCH AND HE REALIZED THAT THE RADIO HAD BEEN TURNED DOWN. I WAS THEN VERBALLY ADVISED BY THE CTLR SERIOUSLY SHAKING UP MY STUDENT. I EXPLAINED THAT WE HAD RADIO FAILURE. HE SAID I'VE BEEN TRYING TO REACH YOU FOR 5 MINUTES, AND DID I KNOW THE CORRECT PROC FOR RADIO FAILURE. HE ASKED IS THERE AN INSTRUCTOR ON BOARD, I ANSWERED YES. AND DID WE KNOW WE WERE 90 DEG OFF HDG. MY STUDENT HAD BECOME SO SHAKEN THAT HE COULD NO LONGER FLY. I THEN PROCEEDED TO TAKE COMMAND OF THE FLT AND DIRECT MSN WHICH WAS UNEVENTFUL. FIRST I WAS UNAWARE THAT RADIO FAILURE HAD OCCURRED AND SO DID NOT GO THROUGH THE RADIO FAILURE PROCS ACCORDING TO PARA 471 OF THE AIM. THE STUDENT WAS SO UPSET THAT HE COULD NO LONGER HOLD HDG OR EVEN FLY. MY STUDENTS CAN NO LONGER TOUCH THE RADIOS WITHOUT MY PERMISSION.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.