Narrative:

I was the radar controller at ZDV, sector 3 (VHF 135.65) which encompasses a fairly large geographical airspace. There were approximately 20 radar-idented aircraft in the sector when the frequency failed -- no main standby or backups available -- with no warning. At the time of the failure, there were at least 2 separate conflicts that needed resolving, 1 within 3 mins. When it was determined that the actual problem was the failure of equipment at the sector, not with the frequency, a controller at neighboring sector had to issue emergency descent and turn clrncs to the aircraft in conflict. After approximately 15 mins, the problem was temporarily corrected at the interphone jack (non-radar controller) but not the radar jack. After a short time, less than 30 mins, the interphone jack failed again and the sector had to be closed. Frequency problems at this sector are recurring. This is a totally unacceptable situation, in addition to being dangerous.

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Original NASA ASRS Text

Title: TELCO JACK AT RADAR SECTOR FAILS RENDERING THE SECTOR INOP.

Narrative: I WAS THE RADAR CTLR AT ZDV, SECTOR 3 (VHF 135.65) WHICH ENCOMPASSES A FAIRLY LARGE GEOGRAPHICAL AIRSPACE. THERE WERE APPROX 20 RADAR-IDENTED ACFT IN THE SECTOR WHEN THE FREQ FAILED -- NO MAIN STANDBY OR BACKUPS AVAILABLE -- WITH NO WARNING. AT THE TIME OF THE FAILURE, THERE WERE AT LEAST 2 SEPARATE CONFLICTS THAT NEEDED RESOLVING, 1 WITHIN 3 MINS. WHEN IT WAS DETERMINED THAT THE ACTUAL PROBLEM WAS THE FAILURE OF EQUIP AT THE SECTOR, NOT WITH THE FREQ, A CTLR AT NEIGHBORING SECTOR HAD TO ISSUE EMER DSCNT AND TURN CLRNCS TO THE ACFT IN CONFLICT. AFTER APPROX 15 MINS, THE PROBLEM WAS TEMPORARILY CORRECTED AT THE INTERPHONE JACK (NON-RADAR CTLR) BUT NOT THE RADAR JACK. AFTER A SHORT TIME, LESS THAN 30 MINS, THE INTERPHONE JACK FAILED AGAIN AND THE SECTOR HAD TO BE CLOSED. FREQ PROBLEMS AT THIS SECTOR ARE RECURRING. THIS IS A TOTALLY UNACCEPTABLE SITUATION, IN ADDITION TO BEING DANGEROUS.

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.