Narrative:

A single ship kc-135 military aircraft on a cross country business mission from eilson AFB, fairbanks, ak, to eglin AFB, valparaiso, fl. Event happened during the final approach and descent phase (and landing phase). Beginning at approximately 300 NM north of eglin AFB, military flight began altering course to avoid numerous embedded thunderstorms. Military flight was under intermittent IMC/VMC until approximately 15 mi north of destination (eglin AFB), at which point the WX cleared significantly to VMC. Prior to breakout from IMC, military flight was on an extended dogleg to final for runway 19, and cleared for ILS to runway 19 at eglin. Upon seeing the runway at approximately 1-2 O'clock position and flying closer to its extended centerline, military flight advised controller that he was turing final to intercept final, navigation #1 and #2 were both tuned to the ILS frequency for runway 19, but identify was scratchy, we think, due to an intercom problem that was subsequently written up after the mission. (By the way, we aborted the same jet 2 days later for the same problem. Intercom in ics mode had all crew members cutting in and out and readable only approximately 80% of the time.) left seat pilot was flying the approach and noticed what he thought to be inoperative ILS localizer courses. On final, military flight was then told to report a 5 mi final, and to follow a cessna aircraft on base. Unknown to military flight X at the time, military flight Y was on final for runway 19 as well. Military flight X told tower he didn't see the cessna and (after a period of time, asked tower if cleared to land). Tower cleared military flight X to land (but in reality, we think it was military flight Y they saw on final, an identical kc-135 aircraft from our same squadron. Military flight X then landed and was told to take a left to exit the runway (but since military flight Y landed at the same time, we think tower saw military flight Y as flight X). Both aircraft, military X or military Y, now at separate airfields, turned left to exit the runway. After several mins of communication confusion with tower, it was finally sorted out that military flight X was not at eglin, but instead at eglin auxiliary. Military flight X then coordination for a VFR departure from eglin auxiliary to eglin, and landed at eglin uneventfully. Relevant factors (in my opinion): 1) crew fatigue - we think this could have been a contributing factor. (Because our show time was XA00, and better rest I think would have helped. 2) perceived inoperative localizer (in reality, the localizer was fine but thought to be inoperative), more inquiry (to tower, for example) to get an update on its status would have helped), ie, more inquiry on the part of the crew at the precise time the perceived ambiguity was discovered. 3) simultaneous, similar aircraft, on the same approach in the same relative position on final led to further confusion and ultimately military flight X being cleared to land.

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Original NASA ASRS Text

Title: RWY INCURSION AFTER LWOC BY A KC135 MAKING A VISUAL APCH TO WHAT HE THOUGHT WAS EGLIN AFB BUT WAS ACTUALLY AN AUX FIELD 10 NM N OF VPS, EGI, FL.

Narrative: A SINGLE SHIP KC-135 MIL ACFT ON A XCOUNTRY BUSINESS MISSION FROM EILSON AFB, FAIRBANKS, AK, TO EGLIN AFB, VALPARAISO, FL. EVENT HAPPENED DURING THE FINAL APCH AND DSCNT PHASE (AND LNDG PHASE). BEGINNING AT APPROX 300 NM N OF EGLIN AFB, MIL FLT BEGAN ALTERING COURSE TO AVOID NUMEROUS EMBEDDED TSTMS. MIL FLT WAS UNDER INTERMITTENT IMC/VMC UNTIL APPROX 15 MI N OF DEST (EGLIN AFB), AT WHICH POINT THE WX CLRED SIGNIFICANTLY TO VMC. PRIOR TO BREAKOUT FROM IMC, MIL FLT WAS ON AN EXTENDED DOGLEG TO FINAL FOR RWY 19, AND CLRED FOR ILS TO RWY 19 AT EGLIN. UPON SEEING THE RWY AT APPROX 1-2 O'CLOCK POS AND FLYING CLOSER TO ITS EXTENDED CTRLINE, MIL FLT ADVISED CTLR THAT HE WAS TURING FINAL TO INTERCEPT FINAL, NAV #1 AND #2 WERE BOTH TUNED TO THE ILS FREQ FOR RWY 19, BUT IDENT WAS SCRATCHY, WE THINK, DUE TO AN INTERCOM PROB THAT WAS SUBSEQUENTLY WRITTEN UP AFTER THE MISSION. (BY THE WAY, WE ABORTED THE SAME JET 2 DAYS LATER FOR THE SAME PROB. INTERCOM IN ICS MODE HAD ALL CREW MEMBERS CUTTING IN AND OUT AND READABLE ONLY APPROX 80% OF THE TIME.) L SEAT PLT WAS FLYING THE APCH AND NOTICED WHAT HE THOUGHT TO BE INOP ILS LOC COURSES. ON FINAL, MIL FLT WAS THEN TOLD TO RPT A 5 MI FINAL, AND TO FOLLOW A CESSNA ACFT ON BASE. UNKNOWN TO MIL FLT X AT THE TIME, MIL FLT Y WAS ON FINAL FOR RWY 19 AS WELL. MIL FLT X TOLD TWR HE DIDN'T SEE THE CESSNA AND (AFTER A PERIOD OF TIME, ASKED TWR IF CLRED TO LAND). TWR CLRED MIL FLT X TO LAND (BUT IN REALITY, WE THINK IT WAS MIL FLT Y THEY SAW ON FINAL, AN IDENTICAL KC-135 ACFT FROM OUR SAME SQUADRON. MIL FLT X THEN LANDED AND WAS TOLD TO TAKE A L TO EXIT THE RWY (BUT SINCE MIL FLT Y LANDED AT THE SAME TIME, WE THINK TWR SAW MIL FLT Y AS FLT X). BOTH ACFT, MIL X OR MIL Y, NOW AT SEPARATE AIRFIELDS, TURNED L TO EXIT THE RWY. AFTER SEVERAL MINS OF COM CONFUSION WITH TWR, IT WAS FINALLY SORTED OUT THAT MIL FLT X WAS NOT AT EGLIN, BUT INSTEAD AT EGLIN AUX. MIL FLT X THEN COORD FOR A VFR DEP FROM EGLIN AUX TO EGLIN, AND LANDED AT EGLIN UNEVENTFULLY. RELEVANT FACTORS (IN MY OPINION): 1) CREW FATIGUE - WE THINK THIS COULD HAVE BEEN A CONTRIBUTING FACTOR. (BECAUSE OUR SHOW TIME WAS XA00, AND BETTER REST I THINK WOULD HAVE HELPED. 2) PERCEIVED INOP LOC (IN REALITY, THE LOC WAS FINE BUT THOUGHT TO BE INOP), MORE INQUIRY (TO TWR, FOR EXAMPLE) TO GET AN UPDATE ON ITS STATUS WOULD HAVE HELPED), IE, MORE INQUIRY ON THE PART OF THE CREW AT THE PRECISE TIME THE PERCEIVED AMBIGUITY WAS DISCOVERED. 3) SIMULTANEOUS, SIMILAR ACFT, ON THE SAME APCH IN THE SAME RELATIVE POS ON FINAL LED TO FURTHER CONFUSION AND ULTIMATELY MIL FLT X BEING CLRED TO LAND.

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.