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Air carrier medium large transport had interference between two VOR stations on the same frequency 180 NM apart.
| Attributes | |
| ACN | 120219 |
| Time | |
| Date | 198908 |
| Day | Fri |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : esl |
| State Reference | WV |
| Altitude | msl bound lower : 19000 msl bound upper : 23000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zdc |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other |
| Flight Phase | cruise other |
| Route In Use | arrival star : star |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : cfi pilot : flight engineer |
| Experience | flight time last 90 days : 250 flight time total : 26000 |
| ASRS Report | 120219 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Events | |
| Anomaly | other anomaly other |
| Independent Detector | other flight crewa |
| Resolutory Action | controller : issued new clearance |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Navigational Facility |
| Air Traffic Incident | other |
| Situations | |
| Navigational Aid | Unspecified |
Narrative:
En route pit to dca, issued the bucko two arrival (esc bucko 2). At 47 DME west of kessel VOR (esl-110.8) and climbing out of FL190 the HSI went full left and the RMI swung to the 7 O'clock position. I selected the volume to check the identify and found erie (eri 110.8) loud and clear. Upon arriving at FL230 found the signal from eri strong on the VOR but the DME continued to count down to esl. Out of FL200 advised ATC we were unable to navigate on the bucko arrival due esl navigation loss. ATC advised the esl was operating normally and cleared us direct dca. It appears that these two locations, eri and esl are too close, 180 NM, to be used in the high altitude structure and could cause serious errors in navigation due to signal interference.
Original NASA ASRS Text
Title: ACR MLG HAD INTERFERENCE BETWEEN TWO VOR STATIONS ON THE SAME FREQ 180 NM APART.
Narrative: ENRTE PIT TO DCA, ISSUED THE BUCKO TWO ARR (ESC BUCKO 2). AT 47 DME W OF KESSEL VOR (ESL-110.8) AND CLIMBING OUT OF FL190 THE HSI WENT FULL LEFT AND THE RMI SWUNG TO THE 7 O'CLOCK POSITION. I SELECTED THE VOLUME TO CHECK THE IDENT AND FOUND ERIE (ERI 110.8) LOUD AND CLEAR. UPON ARRIVING AT FL230 FOUND THE SIGNAL FROM ERI STRONG ON THE VOR BUT THE DME CONTINUED TO COUNT DOWN TO ESL. OUT OF FL200 ADVISED ATC WE WERE UNABLE TO NAVIGATE ON THE BUCKO ARR DUE ESL NAV LOSS. ATC ADVISED THE ESL WAS OPERATING NORMALLY AND CLRED US DIRECT DCA. IT APPEARS THAT THESE TWO LOCATIONS, ERI AND ESL ARE TOO CLOSE, 180 NM, TO BE USED IN THE HIGH ALT STRUCTURE AND COULD CAUSE SERIOUS ERRORS IN NAVIGATION DUE TO SIGNAL INTERFERENCE.
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.