Narrative:

During an instrument approach to ktn I was informed by ATC of a possible sep occurrence. At the time, I was acting and PIC onboard an light transport turbojet aircraft. 1) at approximately xa hours local, on 3/tue/89, I was directed by ATC to maintain 8000' MSL until 11.0 DME northwest of ann and cleared for the ILS DME 1 runway 11 approach at ktn. WX was IFR with tops at 11000' MSL, bases at 1800' MSL, surface visibility 7 mi in light rain, wind gusts to 35 KTS. 2) I proceeded outbnd on the ann 308 degree right to intercept the iech localizer at the iech ILS localizer DME 11.0 fix. The iech 11.0 DME fix is crossed by the ann 308 degree right at 27.8 DME from ann. After passing the 8000' restriction, I initiated a descent to 5700' MSL. Upon arriving at the ann 308 degree right, 27.8 DME fix, I still had not intercepted or crossed the ILS localizer course. Xchking with the first officer's and captain's HSI displays, we verified the lack of course presentation. I continued on the ann 308 degree right to 28.8 DME in hope of getting CDI movement. At this point the NDB, tuned to cmj, confirmed the DME indication that we had passed the ILS localizer course. The ILS localizer course deviation indicator still indicated that course intercept, or passage had not occurred. The localizer navigation warning flags were not in view, and the audio identify signal was still clear. 4) my problem, now, is executing a missed approach based partly on a NAVAID on which I cannot rely for safe navigation. This is further complicated by light to moderate turbulence and icing in IMC. Since I was now doubtful of my exact position, safe terrain clearance became my immediate concern. This approach chart contains several notes: caution: do not permit full scale CDI deflection. Use iech ILS DME when on localizer course. ADF required for missed approach. Caution: rising terrain both side of final approach. Strong winds may cause severe turbulence. Any go around after passing the map will not provide standard obstruction clearance. If approach aborted no turns permitted after passing D8.0 iech ILS inbound, execute published missed approach. The published missed approach, from the missed approach point is climb direct to cmj NDB, thence on the 109 bearing from cmj NDB to D3.5 iech ILS. Intercept ann VOR 326 degree right or 330 degree bearing from ick NDB and continue climb to 5000' to ann VOR or ick NDB. 5) unable to navigation to the missed approach point due to the invalid localizer presentation, and unable to determine our position relative to the course centerline, the only method to join the published missed approach would be to proceed from our present position direct to the cmj NDB. Due to the angular displacement of this NAVAID from the aircraft, I was unable to ensure safe terrain clearance via this route. 6) believing that an emergency was now in progress, I initiated a maximum performance climbing left turn to the ann VOR, the final fix on the missed approach, and my only reliable NAVAID. I instructed the first officer to declare the missed and advise center of our situation. After some difficulty communications with center were re-established. By this time I was approaching 9000' MSL and was advised by center, 'radar contact, maintain 10000' direct ann,' and was given holding instructions. At this point center advised me of a possible sep occurrence. 7) after holding, I was again cleared for the approach. This time I requested and received clearance via the 30.0 DME arc northwest. On this approach the CDI remained at full deflection until after I had passed through the inbound course centerline. This cause a later intercept, however, I was able to regain the localizer before the 11.0 DME fix and completed the approach. 8) contributing factors, in my opinion, were WX, a questionable NAVAID, and a possible DME equipment malfunction on the aircraft. On the final segment of this trip the first officer's DME failed. With respect to the iech ILS localizer, it was reported to me by local ground personnel that an air carrier airline's flight was unable to complete the approach earlier in the day and that it had been OTS in the preceding day. Another source advised me that numerous aircraft have had problems with the iech localizer, that following an aircraft accident 6 yrs ago, the localizer antenna is still existing on top of a decaying temporary structure and that FAA intends to decommission the iech localizer for 3 months for proper repairs but the local pop and air carrier airlines continues to fight against such an outage. The immediate proximity of high terrain with high winds and rain may have an effect on the signal reception as well as the close proximity of aircraft on the ground. I feel this is something that should be investigated immediately. Supplemental information from acn 107771: the contributing factors, we believe after discussing it among ourselves, were of course a very questionable localizer, which seemed to exhibit characteristics of an electronic device with a short in it somewhere, where occasionally it might work unpredictably, and most of the time it works fine. The other factor was WX, not being able to see where the mountains were.

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Original NASA ASRS Text

Title: DUE TO AN APPARENT NAVIGAIONAL AID MALFUNCTION REPORTER ACFT WAS UNABLE TO ESTABLISH ON THE FINAL APCH COURSE AND EXECUTED AN UNPUBLISHED MISSED APCH PROC UNDER EMERGENCY CONDITIONS WHICH MAY OR MAY NOT HAVE RESULTED IN ATC LOSS OF SEPARATION. CONTRIBUTING WAS THE DIFFICULTY REPORTER HAD IN RE-ESTABLISHING CONTACT WITH ATC DURING THE MISSED APCH.

Narrative: DURING AN INSTRUMENT APCH TO KTN I WAS INFORMED BY ATC OF A POSSIBLE SEP OCCURRENCE. AT THE TIME, I WAS ACTING AND PIC ONBOARD AN LTT TURBOJET ACFT. 1) AT APPROX XA HRS LCL, ON 3/TUE/89, I WAS DIRECTED BY ATC TO MAINTAIN 8000' MSL UNTIL 11.0 DME NW OF ANN AND CLRED FOR THE ILS DME 1 RWY 11 APCH AT KTN. WX WAS IFR WITH TOPS AT 11000' MSL, BASES AT 1800' MSL, SURFACE VISIBILITY 7 MI IN LIGHT RAIN, WIND GUSTS TO 35 KTS. 2) I PROCEEDED OUTBND ON THE ANN 308 DEG R TO INTERCEPT THE IECH LOC AT THE IECH ILS LOC DME 11.0 FIX. THE IECH 11.0 DME FIX IS CROSSED BY THE ANN 308 DEG R AT 27.8 DME FROM ANN. AFTER PASSING THE 8000' RESTRICTION, I INITIATED A DSCNT TO 5700' MSL. UPON ARRIVING AT THE ANN 308 DEG R, 27.8 DME FIX, I STILL HAD NOT INTERCEPTED OR CROSSED THE ILS LOC COURSE. XCHKING WITH THE F/O'S AND CAPT'S HSI DISPLAYS, WE VERIFIED THE LACK OF COURSE PRESENTATION. I CONTINUED ON THE ANN 308 DEG R TO 28.8 DME IN HOPE OF GETTING CDI MOVEMENT. AT THIS POINT THE NDB, TUNED TO CMJ, CONFIRMED THE DME INDICATION THAT WE HAD PASSED THE ILS LOC COURSE. THE ILS LOC COURSE DEVIATION INDICATOR STILL INDICATED THAT COURSE INTERCEPT, OR PASSAGE HAD NOT OCCURRED. THE LOC NAV WARNING FLAGS WERE NOT IN VIEW, AND THE AUDIO IDENT SIGNAL WAS STILL CLEAR. 4) MY PROB, NOW, IS EXECUTING A MISSED APCH BASED PARTLY ON A NAVAID ON WHICH I CANNOT RELY FOR SAFE NAV. THIS IS FURTHER COMPLICATED BY LIGHT TO MODERATE TURB AND ICING IN IMC. SINCE I WAS NOW DOUBTFUL OF MY EXACT POS, SAFE TERRAIN CLRNC BECAME MY IMMEDIATE CONCERN. THIS APCH CHART CONTAINS SEVERAL NOTES: CAUTION: DO NOT PERMIT FULL SCALE CDI DEFLECTION. USE IECH ILS DME WHEN ON LOC COURSE. ADF REQUIRED FOR MISSED APCH. CAUTION: RISING TERRAIN BOTH SIDE OF FINAL APCH. STRONG WINDS MAY CAUSE SEVERE TURB. ANY GAR AFTER PASSING THE MAP WILL NOT PROVIDE STANDARD OBSTRUCTION CLRNC. IF APCH ABORTED NO TURNS PERMITTED AFTER PASSING D8.0 IECH ILS INBND, EXECUTE PUBLISHED MISSED APCH. THE PUBLISHED MISSED APCH, FROM THE MISSED APCH POINT IS CLB DIRECT TO CMJ NDB, THENCE ON THE 109 BEARING FROM CMJ NDB TO D3.5 IECH ILS. INTERCEPT ANN VOR 326 DEG R OR 330 DEG BEARING FROM ICK NDB AND CONTINUE CLB TO 5000' TO ANN VOR OR ICK NDB. 5) UNABLE TO NAV TO THE MISSED APCH POINT DUE TO THE INVALID LOC PRESENTATION, AND UNABLE TO DETERMINE OUR POS RELATIVE TO THE COURSE CENTERLINE, THE ONLY METHOD TO JOIN THE PUBLISHED MISSED APCH WOULD BE TO PROCEED FROM OUR PRESENT POS DIRECT TO THE CMJ NDB. DUE TO THE ANGULAR DISPLACEMENT OF THIS NAVAID FROM THE ACFT, I WAS UNABLE TO ENSURE SAFE TERRAIN CLRNC VIA THIS ROUTE. 6) BELIEVING THAT AN EMER WAS NOW IN PROGRESS, I INITIATED A MAX PERFORMANCE CLBING LEFT TURN TO THE ANN VOR, THE FINAL FIX ON THE MISSED APCH, AND MY ONLY RELIABLE NAVAID. I INSTRUCTED THE F/O TO DECLARE THE MISSED AND ADVISE CENTER OF OUR SITUATION. AFTER SOME DIFFICULTY COMS WITH CENTER WERE RE-ESTABLISHED. BY THIS TIME I WAS APCHING 9000' MSL AND WAS ADVISED BY CENTER, 'RADAR CONTACT, MAINTAIN 10000' DIRECT ANN,' AND WAS GIVEN HOLDING INSTRUCTIONS. AT THIS POINT CENTER ADVISED ME OF A POSSIBLE SEP OCCURRENCE. 7) AFTER HOLDING, I WAS AGAIN CLRED FOR THE APCH. THIS TIME I REQUESTED AND RECEIVED CLRNC VIA THE 30.0 DME ARC NW. ON THIS APCH THE CDI REMAINED AT FULL DEFLECTION UNTIL AFTER I HAD PASSED THROUGH THE INBND COURSE CENTERLINE. THIS CAUSE A LATER INTERCEPT, HOWEVER, I WAS ABLE TO REGAIN THE LOC BEFORE THE 11.0 DME FIX AND COMPLETED THE APCH. 8) CONTRIBUTING FACTORS, IN MY OPINION, WERE WX, A QUESTIONABLE NAVAID, AND A POSSIBLE DME EQUIP MALFUNCTION ON THE ACFT. ON THE FINAL SEGMENT OF THIS TRIP THE F/O'S DME FAILED. WITH RESPECT TO THE IECH ILS LOC, IT WAS RPTED TO ME BY LCL GND PERSONNEL THAT AN ACR AIRLINE'S FLT WAS UNABLE TO COMPLETE THE APCH EARLIER IN THE DAY AND THAT IT HAD BEEN OTS IN THE PRECEDING DAY. ANOTHER SOURCE ADVISED ME THAT NUMEROUS ACFT HAVE HAD PROBS WITH THE IECH LOC, THAT FOLLOWING AN ACFT ACCIDENT 6 YRS AGO, THE LOC ANTENNA IS STILL EXISTING ON TOP OF A DECAYING TEMPORARY STRUCTURE AND THAT FAA INTENDS TO DECOMMISSION THE IECH LOC FOR 3 MONTHS FOR PROPER REPAIRS BUT THE LCL POP AND ACR AIRLINES CONTINUES TO FIGHT AGAINST SUCH AN OUTAGE. THE IMMEDIATE PROX OF HIGH TERRAIN WITH HIGH WINDS AND RAIN MAY HAVE AN EFFECT ON THE SIGNAL RECEPTION AS WELL AS THE CLOSE PROX OF ACFT ON THE GND. I FEEL THIS IS SOMETHING THAT SHOULD BE INVESTIGATED IMMEDIATELY. SUPPLEMENTAL INFO FROM ACN 107771: THE CONTRIBUTING FACTORS, WE BELIEVE AFTER DISCUSSING IT AMONG OURSELVES, WERE OF COURSE A VERY QUESTIONABLE LOC, WHICH SEEMED TO EXHIBIT CHARACTERISTICS OF AN ELECTRONIC DEVICE WITH A SHORT IN IT SOMEWHERE, WHERE OCCASIONALLY IT MIGHT WORK UNPREDICTABLY, AND MOST OF THE TIME IT WORKS FINE. THE OTHER FACTOR WAS WX, NOT BEING ABLE TO SEE WHERE THE MOUNTAINS WERE.

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.