Narrative:

While talking with knoxville approach we received clearance for the approach to mcminn county airport. We were inside 10 mi of the beacon and established on the inbound course for runway 20, so I began descent from 3100' to the published MDA. During this descent, approach called with a low altitude alert. When I questioned this, approach said that the clearance was to maintain 3100' until the beacon outbnd. We either did not receive that or it was misunderstood. We did comply, however, with the second request from approach by climbing back to 3100'. We then had to fly to the beacon, perform a 180 degree turn and fly the procedure turn only to get right back to where we were when we first began the descent. In any event, we could not see any reason for a clearance like that because as earlier mentioned, we were already established for the approach. Callback conversation with reporter revealed the following: reporter admits to misunderstanding the procedure and why the clearance was given to maintain their altitude to the NDB and then proceed out in a procedure turn prior to descending to MDA. First officer and captain are now aware that 'nopt' must appear on the approach plate for a straight in approach to be accomplished. Supplemental information from acn 140078: approaching from the nne we were established on the final approach for the NDB runway 20 approach, about 15 mi out. Last assigned altitude given by approach was 3100'. Knoxville, around PM15 local time, cleared us for the approach 8 mi from the beacon which is located on the field. As we started down, approach called informing us that we were 300' below our assigned altitude of 3100'. This we quickly corrected. Knoxville approach again read back our clearance which was to 'maintain 3100' to the beacon.' this we never head the first time, or the clearance would have been flown accordingly.

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Original NASA ASRS Text

Title: DEVIATION FROM CLRNC AND PUBLISHED APCH PROC.

Narrative: WHILE TALKING WITH KNOXVILLE APCH WE RECEIVED CLRNC FOR THE APCH TO MCMINN COUNTY ARPT. WE WERE INSIDE 10 MI OF THE BEACON AND ESTABLISHED ON THE INBND COURSE FOR RWY 20, SO I BEGAN DSCNT FROM 3100' TO THE PUBLISHED MDA. DURING THIS DSCNT, APCH CALLED WITH A LOW ALT ALERT. WHEN I QUESTIONED THIS, APCH SAID THAT THE CLRNC WAS TO MAINTAIN 3100' UNTIL THE BEACON OUTBND. WE EITHER DID NOT RECEIVE THAT OR IT WAS MISUNDERSTOOD. WE DID COMPLY, HOWEVER, WITH THE SECOND REQUEST FROM APCH BY CLBING BACK TO 3100'. WE THEN HAD TO FLY TO THE BEACON, PERFORM A 180 DEG TURN AND FLY THE PROC TURN ONLY TO GET RIGHT BACK TO WHERE WE WERE WHEN WE FIRST BEGAN THE DSCNT. IN ANY EVENT, WE COULD NOT SEE ANY REASON FOR A CLRNC LIKE THAT BECAUSE AS EARLIER MENTIONED, WE WERE ALREADY ESTABLISHED FOR THE APCH. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR ADMITS TO MISUNDERSTANDING THE PROC AND WHY THE CLRNC WAS GIVEN TO MAINTAIN THEIR ALT TO THE NDB AND THEN PROCEED OUT IN A PROC TURN PRIOR TO DSNDING TO MDA. F/O AND CAPT ARE NOW AWARE THAT 'NOPT' MUST APPEAR ON THE APCH PLATE FOR A STRAIGHT IN APCH TO BE ACCOMPLISHED. SUPPLEMENTAL INFO FROM ACN 140078: APCHING FROM THE NNE WE WERE ESTABLISHED ON THE FINAL APCH FOR THE NDB RWY 20 APCH, ABOUT 15 MI OUT. LAST ASSIGNED ALT GIVEN BY APCH WAS 3100'. KNOXVILLE, AROUND PM15 LCL TIME, CLRED US FOR THE APCH 8 MI FROM THE BEACON WHICH IS LOCATED ON THE FIELD. AS WE STARTED DOWN, APCH CALLED INFORMING US THAT WE WERE 300' BELOW OUR ASSIGNED ALT OF 3100'. THIS WE QUICKLY CORRECTED. KNOXVILLE APCH AGAIN READ BACK OUR CLRNC WHICH WAS TO 'MAINTAIN 3100' TO THE BEACON.' THIS WE NEVER HEAD THE FIRST TIME, OR THE CLRNC WOULD HAVE BEEN FLOWN ACCORDINGLY.

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.