Narrative:

On apr/xa/97, and apr/xf/97, ZME south area was subjected to an unsafe condition due to the loss of the primary cable feeding the coordination lines and frequencys. On apr/xa/97, the loss was from approximately YA45 am to YB15 pm local time and caused 60 lines to be lost. On apr/xf/97, the loss was from approximately XA30 am to XC15 pm. These outages caused sectors to lose all frequency sites (main, standby, and buec) and numerous communication lines with other facilities. These frequency losses caused one sector to work aircraft within 2-3 sectors, thus increasing the traffic load and causing an extremely large area to be monitored by the controller. The sector workload was additionally impacted by the loss of the coordination lines and computer interfacility with adjacent facilities. The controller was unable to call the adjacent facilities, and the automated data and handoffs to these facilities were failing and required excess time contacting these facilities through the ring-and-flash lines. With the advanced technology we have today, the FAA should not be dependent on ground cables for their operations. Microwaves or satellites should be used for frequencys and coordination lines. The ground cable should be a back-up for the primary system. There is currently no immediate backup in the event of the loss of a ground cable. Where ground cables are used, they should be secure from loss by accidental means.

Related reports:

Google
 

Original NASA ASRS Text

Title: RPTR SIT OF A PRIMARY CABLE PROVIDING FREQ AND COORD LINES TO ALL S AREA CTR SECTORS BEING CUT ON 2 SEPARATE OCCASIONS. OUTAGE REQUIRED OTHER SECTORS TO HANDLE WORKLOAD WHICH WAS IMPACTED WITH THE LOSS OF COM LINES AND COMPUTER INTERFACE. INTERFAC COORD AND AUTOMATED HDOF CAPABILITIES WERE AFFECTED BY OUTAGE.

Narrative: ON APR/XA/97, AND APR/XF/97, ZME S AREA WAS SUBJECTED TO AN UNSAFE CONDITION DUE TO THE LOSS OF THE PRIMARY CABLE FEEDING THE COORD LINES AND FREQS. ON APR/XA/97, THE LOSS WAS FROM APPROX YA45 AM TO YB15 PM LCL TIME AND CAUSED 60 LINES TO BE LOST. ON APR/XF/97, THE LOSS WAS FROM APPROX XA30 AM TO XC15 PM. THESE OUTAGES CAUSED SECTORS TO LOSE ALL FREQ SITES (MAIN, STANDBY, AND BUEC) AND NUMEROUS COM LINES WITH OTHER FACILITIES. THESE FREQ LOSSES CAUSED ONE SECTOR TO WORK ACFT WITHIN 2-3 SECTORS, THUS INCREASING THE TFC LOAD AND CAUSING AN EXTREMELY LARGE AREA TO BE MONITORED BY THE CTLR. THE SECTOR WORKLOAD WAS ADDITIONALLY IMPACTED BY THE LOSS OF THE COORD LINES AND COMPUTER INTERFAC WITH ADJACENT FACILITIES. THE CTLR WAS UNABLE TO CALL THE ADJACENT FACILITIES, AND THE AUTOMATED DATA AND HDOFS TO THESE FACILITIES WERE FAILING AND REQUIRED EXCESS TIME CONTACTING THESE FACILITIES THROUGH THE RING-AND-FLASH LINES. WITH THE ADVANCED TECHNOLOGY WE HAVE TODAY, THE FAA SHOULD NOT BE DEPENDENT ON GND CABLES FOR THEIR OPS. MICROWAVES OR SATELLITES SHOULD BE USED FOR FREQS AND COORD LINES. THE GND CABLE SHOULD BE A BACK-UP FOR THE PRIMARY SYS. THERE IS CURRENTLY NO IMMEDIATE BACKUP IN THE EVENT OF THE LOSS OF A GND CABLE. WHERE GND CABLES ARE USED, THEY SHOULD BE SECURE FROM LOSS BY ACCIDENTAL MEANS.

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.