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Reporter situation of frequency failure with 2 air carrier aircraft in potential conflict at the same altitude. Frequency had been returned after release to maintenance for previous problems. Reporter stated backup frequencys were out of order. Other controller used his frequency to relay control data to avoid conflict less than standard separation.
| Attributes | |
| ACN | 359263 |
| Time | |
| Date | 199701 |
| Day | Tue |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : azq |
| State Reference | KY |
| Altitude | msl bound lower : 33000 msl bound upper : 33000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zid |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise other descent other |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Experience | controller radar : 11 |
| ASRS Report | 359263 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Events | |
| Anomaly | conflict : airborne less severe other anomaly other |
| Independent Detector | other controllera |
| Resolutory Action | controller : issued new clearance other |
| Consequence | Other |
| Miss Distance | vertical : 2000 |
| Supplementary | |
| Primary Problem | Navigational Facility |
| Air Traffic Incident | other |
Narrative:
Air carrier Y at FL330 was in conflict with air carrier X at FL330 in the beckley, wv, high altitude sector at ZID. I was preparing to vector the 2 aircraft when I experienced a total radio failure of frequency 124.57. Backup frequencys were also out of order. Another controller offered to relay a clearance through an aircraft he was working. I advised him to have air carrier X descend to FL310 immediately. Air carrier X did not initially accept the clearance, but he did contact the other controller on 119.52, who reiterated the clearance. The aircraft were 4 mins from collision when the frequency failed. Air carrier X finally initiated his descent about 1 1/2 mins from merger, descending rapidly enough to maintain separation. This frequency, 124.57, had been causing problems all day. It had been released to maintenance, and it was returned to service only shortly before this incident. Had the adjacent controller not suggested relaying the clearance, a serious accident may have resulted.
Original NASA ASRS Text
Title: RPTR SIT OF FREQ FAILURE WITH 2 ACR ACFT IN POTENTIAL CONFLICT AT THE SAME ALT. FREQ HAD BEEN RETURNED AFTER RELEASE TO MAINT FOR PREVIOUS PROBS. RPTR STATED BACKUP FREQS WERE OUT OF ORDER. OTHER CTLR USED HIS FREQ TO RELAY CTL DATA TO AVOID CONFLICT LTSS.
Narrative: ACR Y AT FL330 WAS IN CONFLICT WITH ACR X AT FL330 IN THE BECKLEY, WV, HIGH ALT SECTOR AT ZID. I WAS PREPARING TO VECTOR THE 2 ACFT WHEN I EXPERIENCED A TOTAL RADIO FAILURE OF FREQ 124.57. BACKUP FREQS WERE ALSO OUT OF ORDER. ANOTHER CTLR OFFERED TO RELAY A CLRNC THROUGH AN ACFT HE WAS WORKING. I ADVISED HIM TO HAVE ACR X DSND TO FL310 IMMEDIATELY. ACR X DID NOT INITIALLY ACCEPT THE CLRNC, BUT HE DID CONTACT THE OTHER CTLR ON 119.52, WHO REITERATED THE CLRNC. THE ACFT WERE 4 MINS FROM COLLISION WHEN THE FREQ FAILED. ACR X FINALLY INITIATED HIS DSCNT ABOUT 1 1/2 MINS FROM MERGER, DSNDING RAPIDLY ENOUGH TO MAINTAIN SEPARATION. THIS FREQ, 124.57, HAD BEEN CAUSING PROBS ALL DAY. IT HAD BEEN RELEASED TO MAINT, AND IT WAS RETURNED TO SVC ONLY SHORTLY BEFORE THIS INCIDENT. HAD THE ADJACENT CTLR NOT SUGGESTED RELAYING THE CLRNC, A SERIOUS ACCIDENT MAY HAVE RESULTED.
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.