Narrative:

During recurrent training with instrument rated pilot, we were cleared for NDB runway 29R approach at sck. Handoff to tower from approach had occurred outside marker (LOM). Student strayed slightly east of course, corrected. After correction, due to equipment (ADF) display error, he appeared to be on course. (Actually, we were northeast of course, based on my view of airport). I allowed him to continue, wishing for him to 'successfully' complete the approach, and appreciate the limitations of ADF equipment. I canceled our IFR status with the tower, so that they could allow us to continue the approach 'off course.' the area around the airport is mostly undeveloped. However, there is a correctional facility 2- 3 mi northeast of airport. While I was vigilant for traffic in vicinity, I inadvertently allowed aircraft to overfly the facility at MDA (400 ft AGL). I believe this was improper, due to my knowledge of our off-course status, and since our low altitude was a result of my desire for realism in training, not 'necessary for takeoff or landing' (91.119). An altitude of 500 ft AGL should have been maintained in this situation. I could have specified circling minimums, or simply revised MDA to 500 ft. I am normally alert to this sort of training excursion into a possible conflict with a regulatory (or common sense safety) requirement due to my 3000 hours as CFI-ia-mei. I am not complacent. However, on this day, I was fatigued and uncomfortable from a medical condition which I thought would not impact my judgement or vigilance. Also, this pilot was absorbing more of my attention than usual due to his problems with NDB procedures. The important consideration of what was underneath us escaped my situational awareness. I will be more alert to this situation in the future.

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Original NASA ASRS Text

Title: PLT OF AN SMA SEL FLEW BELOW THE MINIMUM SAFE ALT DURING THE EXECUTION OF AN NDB INST APCH.

Narrative: DURING RECURRENT TRAINING WITH INST RATED PLT, WE WERE CLRED FOR NDB RWY 29R APCH AT SCK. HDOF TO TWR FROM APCH HAD OCCURRED OUTSIDE MARKER (LOM). STUDENT STRAYED SLIGHTLY E OF COURSE, CORRECTED. AFTER CORRECTION, DUE TO EQUIP (ADF) DISPLAY ERROR, HE APPEARED TO BE ON COURSE. (ACTUALLY, WE WERE NE OF COURSE, BASED ON MY VIEW OF ARPT). I ALLOWED HIM TO CONTINUE, WISHING FOR HIM TO 'SUCCESSFULLY' COMPLETE THE APCH, AND APPRECIATE THE LIMITATIONS OF ADF EQUIP. I CANCELED OUR IFR STATUS WITH THE TWR, SO THAT THEY COULD ALLOW US TO CONTINUE THE APCH 'OFF COURSE.' THE AREA AROUND THE ARPT IS MOSTLY UNDEVELOPED. HOWEVER, THERE IS A CORRECTIONAL FACILITY 2- 3 MI NE OF ARPT. WHILE I WAS VIGILANT FOR TFC IN VICINITY, I INADVERTENTLY ALLOWED ACFT TO OVERFLY THE FACILITY AT MDA (400 FT AGL). I BELIEVE THIS WAS IMPROPER, DUE TO MY KNOWLEDGE OF OUR OFF-COURSE STATUS, AND SINCE OUR LOW ALT WAS A RESULT OF MY DESIRE FOR REALISM IN TRAINING, NOT 'NECESSARY FOR TKOF OR LNDG' (91.119). AN ALT OF 500 FT AGL SHOULD HAVE BEEN MAINTAINED IN THIS SIT. I COULD HAVE SPECIFIED CIRCLING MINIMUMS, OR SIMPLY REVISED MDA TO 500 FT. I AM NORMALLY ALERT TO THIS SORT OF TRAINING EXCURSION INTO A POSSIBLE CONFLICT WITH A REGULATORY (OR COMMON SENSE SAFETY) REQUIREMENT DUE TO MY 3000 HRS AS CFI-IA-MEI. I AM NOT COMPLACENT. HOWEVER, ON THIS DAY, I WAS FATIGUED AND UNCOMFORTABLE FROM A MEDICAL CONDITION WHICH I THOUGHT WOULD NOT IMPACT MY JUDGEMENT OR VIGILANCE. ALSO, THIS PLT WAS ABSORBING MORE OF MY ATTN THAN USUAL DUE TO HIS PROBS WITH NDB PROCS. THE IMPORTANT CONSIDERATION OF WHAT WAS UNDERNEATH US ESCAPED MY SITUATIONAL AWARENESS. I WILL BE MORE ALERT TO THIS SIT IN THE FUTURE.

Data retrieved from NASA's ASRS site as of July 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.