,WHEN ALL TWENTY-TWO ,,US AIR ROUTE
TRAFFIC CONTROL CENTERS WENT DARK
TOGETHER ON ,FRIDAY1 THE ARCHITECTURE
TOLD THE STORY BEFORE THE INVESTIGATORS
COULD3 THEY ALL RIDE THE SAME WIRE4
,AMERICA'S AIR TRAFFIC CONTROL DOES NOT
RUN ON TWENTY-TWO INDEPENDENT NETWORKS 
IT RUNS ON ONE1 A PRIVATE
CONTRACTOR-OPERATED BACKBONE THAT HAS
BEEN FAILING REGIONALLY FOR EIGHTEEN
MONTHS STRAIGHT4 ,FRIDAY MAY SIMPLY BE
THE DAY IT FAILED NATIONALLY4
,THE NETWORK NOBODY'S HEARD OF
,THE ,,FAA ,TELECOMMUNICATIONS
,INFRASTRUCTURE "<,,FTI"> IS THE
CONNECTIVE TISSUE OF THE ,NATIONAL
,AIRSPACE ,SYSTEM3 A PRIVATE1 NATIONWIDE
WIDE-AREA NETWORK DESIGNED1 BUILT1
OWNED1 OPERATED AND MAINTAINED BY
,L#C;,HARRIS UNDER A MANAGED-SERVICES
CONTRACT4 ,PER ,L#C;,HARRIS'S OWN
PROGRAM LITERATURE1 IT INTERCONNECTS
MORE THAN #D1DJJ ,,FAA SITES CARRYING
MORE THAN #BI1JJJ TELECOMMUNICATIONS
SERVICES  VOICE1 DATA1 RADAR AND VIDEO 
SPANNING TERRESTRIAL1 SATELLITE AND
MICROWAVE LAST-MILE LINKS1 MARKETED AT
#II4IIIGA.0 RELIABILITY4 ,CRITICALLY1
,L#C;,HARRIS OWNS THE EQUIPMENT AND
LEASES THE UNDERLYING TELECOM CAPACITY3
WHEN THE ,,FAA'S SYSTEMS TALK TO EACH
OTHER1 THEY ARE TALKING OVER A
CONTRACTOR'S WIRES4.<CITE3 ,L#C;,HARRIS1
.<8,,FAA ,TELECOMMUNICATIONS
,INFRASTRUCTURE "<,,FTI"> ,PROGRAM01
PROGRAM LITERATURE.>.>
,THE PARADE OF FAILURES
,REGIONAL VERSIONS OF ,FRIDAY'S EVENT
HAVE BEEN ARRIVING ON A NEAR-MONTHLY
CADENCE  EVERY ONE MUNDANE1 EVERY ONE
INSTRUCTIVE3
"9 ,SPRING #BJBE  ,PHILADELPHIA4
,REPEATED RADAR OUTAGES AT ,PHILADELPHIA
,,TRACON2 IN ONE INCIDENT THE FACILITY
LOST BOTH PRIMARY AND BACKUP DATA LINES
SIMULTANEOUSLY4 ,,AP TRACED A FAILURE TO
A SWITCH ON THE PRIMARY COMMUNICATIONS
LINE4.<CITE3 ,ASSOCIATED ,PRESS1
.<8,TECHNICAL PROBLEMS WITH AIR TRAFFIC
CONTROL SHOW THE NEED FOR AN OVERHAUL01
#BJBE.>.> "9 ,JUNE #BJBE  ,JACKSONVILLE
,,ARTCC4 ,A FIBER CUT TOOK RADAR1
FREQUENCIES AND AUTOMATION OFFLINE2
,L#C;,HARRIS AND THE LOCAL EXCHANGE
CARRIER WERE DISPATCHED TO REPAIR
IT4.<CITE3 ,REUTERS1 .<8,,FAA SAYS
,JACKSONVILLE ,,ARTCC EXPERIENCING
TELECOMMUNICATIONS ISSUE01 #BJ ,JUNE
#BJBE.>.> "9 ,SEPTEMBER #AI1 #BJBF 
,DALLAS4 ,FRONTIER ,COMMUNICATIONS CREWS
ACCIDENTALLY SEVERED TWO FIBER CABLES
CARRYING BOTH PRIMARY AND BACKUP LINKS
INTO ,DALLAS ,,TRACON  AND
,L#C;,HARRIS'S REDUNDANCY FAILED TO
OPERATE CORRECTLY4 ,HUNDREDS OF FLIGHTS
CANCELED1 #AJJ1JJJ"6 TRAVELERS
STRANDED4.<CITE3 ,AERO,TIME1 .<8,DALLAS
,,ATC OUTAGE EXPOSES MORE WEAKNESSES IN
,,US AVIATION INFRASTRUCTURE01
,SEPTEMBER #BJBF.>.> "9 ,SEPTEMBER
#BA#BC1 #BJBF  ,PHILADELPHIA AGAIN4
,ERROR MESSAGES ON A TELECOM CIRCUIT
PROMPTED ,L#C;,HARRIS TO SHIFT TO A
BACKUP FIBER LINE2 THE RESULTING OUTAGE
STILL SNARLED THOUSANDS OF ,EAST ,COAST
FLIGHTS4.<CITE3 ,REUTERS1 .<8,,US ,,FAA
SAYS ERROR MESSAGES IN
TELECOMMUNICATIONS CIRCUIT PROMPTED
SHIFT TO BACKUP01 #BC ,SEPTEMBER
#BJBF.>.> "9 ,NOVEMBER #AC1 #BJBF 
EVERYWHERE4 ,THE SAME FAILURE SIGNATURE1
NOW AT ALL #BB CENTERS SIMULTANEOUSLY3 A
8TELECOMMUNICATIONS OUTAGE10 PER
,,DHS4.<CITE3 ,THE ,WASHINGTON ,POST1
.<8,,FAA GROUNDS FLIGHTS AT ,U4,S4
AIRPORTS01 #AC ,NOVEMBER #BJBF.>.>
,WHY THE REDUNDANCY KEEPS FAILING
,THE RECURRING THEME ACROSS THESE EVENTS
IS NOT A SINGLE WEAK LINK  IT IS
DESIGNED REDUNDANCY THAT DOESN'T SURVIVE
CONTACT3 TWO FIBER PATHS CUT IN THE SAME
TRENCH "<,DALLAS">1 A BACKUP THAT
DOESN'T TAKE OVER CLEANLY
"<,PHILADELPHIA1 ,DALLAS">1 MAINTENANCE
ON A PRIMARY THAT EXPOSES A FRAGILE
SECONDARY "<,SEPTEMBER">4 ,,FAA
OFFICIALS HAVE CONCEDED THAT MUCH OF THE
SYSTEM STILL RUNS ON DECADES-OLD
INFRASTRUCTURE DEPENDENT ON EXTERNAL
TELECOM PROVIDERS1 PATCHED AND UPGRADED
BUT RETAINING ANALOG-ERA
EQUIPMENT4.<CITE3 ,AERO,TIME1 .<8,DALLAS
,,ATC OUTAGE EXPOSES MORE WEAKNESSES IN
,,US AVIATION INFRASTRUCTURE01
,SEPTEMBER #BJBF.>.>
,A SHARED BACKBONE IS EFFICIENT EXACTLY
UNTIL IT ISN'T4 ,EVERY REGIONAL EVENT
SINCE MID-#BJBE WAS A DRESS REHEARSAL3
THE BLAST RADIUS GROWS ONLY BECAUSE THE
DEPENDENCY IS NATIONAL4 ,A SINGLE
BACKBONE FAULT TOUCHING ALL #BB CENTERS
PRODUCES THE OBSERVED SIGNATURE  A
SIMULTANEOUS NATIONAL STOP  WITH NO
ADVERSARY REQUIRED4
,WHAT IT MEANS FOR THE INVESTIGATION
,FRIDAY'S EVENT IS UNREMARKABLE IN
EVERYTHING EXCEPT SCALE  AND SCALE IS
WHAT A COMMON-MODE FAILURE LOOKS LIKE
WHEN IT FINALLY HAPPENS4 ,THE COMPANION
ANALYSIS ARGUING THIS IS THE MOST
PROBABLE EXPLANATION IS AT ,WHY ,THE
,SKIES ,WENT ,DARK2 THE CASE THAT THE
SAME SIGNATURE COULD CONCEAL A
DEMONSTRATION ATTACK  SINCE
LIVING-OFF-THE-LAND INTRUSIONS ARE BUILT
TO LOOK LIKE FAULTS  IS AT ,CHINAS
,FIRST ,CYBER ,PEARL ,HARBOR4 ,BOTH REST
ON THE SAME UNCOMFORTABLE TRUTH THIS
ARTICLE DOCUMENTS3 THE ,,FAA CANNOT
CURRENTLY TELL THE DIFFERENCE BETWEEN
ITS OWN DECAY AND SOMEONE ELSE'S WORK4
,SEE ALSO
"9 ,,FAA ,GROUNDS ,ALL ,,US ,FLIGHTS
,NOVEMBER #AC  HUB COVERAGE "9 ,WHAT ,IS
,,,SMART FAA AI,' ,AIR ,TRAFFIC ,SYSTEM 
THE NEW VARIABLE RIDING THE SAME
BACKBONE "9 ,EVERY ,TIME ,AMERICA
,GROUNDED ,EVERY ,FLIGHT "9 ,,ALB ,WIKI
,LAUNCHES ,NEWS