RPTR CLAIMS THERE IS AN INTERMITTENT PROB WHEN THE LCL CTLR LOSES COM WITH ACFT IN POS ON RWY 5R. RPTR STATES IN THE RPTED INCIDENT THAT ANOTHER ACFT NEAR THE APCH END OF THE RWY WAS USED TO RELAY THE TKOF CLRNC FROM THE TWR. TFC ON FINAL FOR RWY 5R HAD TO BE SWITCHED TO RWY 5L BECAUSE OF THE COM PROB. PROB IS ONGOING AND IS ADDRESSED IN THE LCL SOP.

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THERE IS A LONG STANDING; INTERMITTENT PROB AT THE RDU ARPT THAT IS A SEVERE IMPEDIMENT TO SAFETY. THE PROB DEALS WITH A 'BLANK SPOT' ON THE APCH END OF RWY 5R. WE HAVE SITS WHEN A DEPARTING ACFT IS TAXIED INTO POS TO HOLD; AND WHEN THE TKOF CLRNC IS ISSUED; WE HAVE LOST COMS WITH THE ACFT. THE PROB IS RECOGNIZED AS SERIOUS ENOUGH TO BE ADDRESSED IN OUR LCL SOP ORDER RDU 7110.65 AS A POTENTIAL PROB AREA (ATTACHMENT 2). THIS ISSUE HAS BEEN ADDRESSED ON AND OFF FOR YRS WITH NO PERMANENT RESOLUTION. WHILE THE APPLICATION OF ATC PROCS SHOULD; IN THEORY; PREVENT ANY MISHAPS; THIS PARTICULAR PROB IS A DISASTER WAITING TO HAPPEN. WHEN YOU CLR AN ACFT FOR TKOF AND YOUR ACTIONS ARE BASED ON ANTICIPATED PLT ACTION; AND THE PLT DOES NOT DO WHAT YOU EXPECTED; ANY DIVERSION OF ATTN COULD RESULT; IN THIS CASE; IN AN ARRIVING ACFT LNDG ON TOP OF THE ACFT SITTING ON THE RWY. BUT FOR THE LOSS OF COMS; THE ACFT WOULD NOT BE SITTING ON THE RWY. AN INCIDENT THAT OCCURRED ON JUN/XA/97 EXEMPLIFIES THIS SCENARIO. AT APPROX XX02Z A C560 WAS TAXIED INTO POS TO HOLD ON RWY 5R. AN ACR MD80 WAS ON A 7 MI FINAL TO RWY 5R AND CLRED TO LAND. WHEN THE PRECEDING ARR CLRED THE RWY; THE C560 WAS CLRED FOR TKOF. NO RESPONSE WAS RECEIVED. AFTER SEVERAL XMISSIONS ATTEMPTING TO ESTABLISH COMS; THE LCL CTLR ATTEMPTED TO USE THE BACKUP RADIO IN THE TWR (THIS HAS BECOME STANDARD PROC FOR THIS SIT). THE BACKUP RADIO DID NOT WORK BECAUSE THE ANTENNA CABLE HAD BEEN BROKEN OFF. BY THIS TIME; THE ACR WAS 2.5 MI FINAL; AND CHANGED TO RWY 5L TO PREVENT A GAR. WITH SAFETY NOW ENSURED; A RELAY BTWN THE LCL CTLR AND ANOTHER DEPARTING ACFT WAS ESTABLISHED; AND THE C560 RECEIVED AND ACKNOWLEDGED HIS TKOF CLRNC THROUGH A BA31 AT THE APCH END OF RWY 5R. ONCE AGAIN; LUCK WAS ON OUR SIDE. VISUAL APCHS WERE IN USE. THERE WAS ANOTHER ACFT IN THE VICINITY TO ASSIST THE LCL CTLR. THERE WAS NO OTHER ACFT ON FINAL FOR RWY 5L. THERE WAS NO OTHER ACFT ON RWY 5L WAITING DEP. THE CTLR'S ATTN WAS NOT DIVERTED AND THE SIT WAS RECOGNIZED IMMEDIATELY. THESE ARE JUST TOO MANY UNCTLED VARIABLES THAT WE ARE DEPENDING ON TO ENSURE A SAFE OP. ONE OTHER FACTOR THAT IS CONSISTENT THROUGHOUT EACH OF THESE INCIDENTS IS THAT WE ARE ALWAYS (AT LEAST WHEN THE EQUIP IS NOT PHYSICALLY BROKEN) ABLE TO ESTABLISH COMS; WITH THE ACFT ON RWY 5R; USING THE BACKUP TRANSCEIVERS LOCATED IN THE TWR CAB. THE ANTENNA FOR THIS TRANSCEIVER IS LOCATED ON THE TOP OF THE TWR. AIRWAYS FACILITIES AT RDU ATCT HAS INDICATED THAT A POSSIBLE REMEDY TO THE PROB IS TO RELOCATE THE XMITTER INVOLVED (TWR FREQ 119.3) TO THE TOP OF THE TWR CAB. YRS AGO WHEN DEALING WITH THE PROB; AN AIRWAYS FACILITIES TECHNICIAN INDICATED THAT PLACING A REMOTE XMITTER/RECEIVER (RTR) AT THE APCH END OF RWY 5R SHOULD ALSO RESOLVE THE PROB.