AN ACR FLC HAS THEIR WX RADAR BECOME UNUSABLE DUE TO ATTENUATION FROM WATER ON THE RADOME CAUSING THE SCREEN TO TURN GREEN WITH NO DEFINITIVE RETURNS. ADDITIONALLY; THE WINDSCREEN WIPERS WERE UNABLE TO WIPE MORE THAN A NARROW STRIP CLR DUE TO THE BULGING OF THE GLASS COMPOSITE FROM PAST PRESSURIZATION CYCLES.

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WHILE OPERATING A FLT ON AN A320-232 AIRBUS; ON MAY/SAT/96 FROM ORD TO DCA WE EXPERIENCED SEVERAL OPERATIONAL DIFFICULTIES. THE FLT WAS CONDUCTED ON A RECENTLY DELIVERED ACFT AND DEPARTED THE GATE IN CHICAGO AT XA17 CST AND ARRIVED AT THE GATE IN WASHINGTON DC AT XD23 EST. IN ADDITION TO THE TWO REGULAR MEMBERS OF THE COCKPIT CREW; WE HAD A COMPANY PLT ON THE JUMP SEAT DURING THE ENTIRE FLT. THE WX FORECAST FOR DCA WAS 45 BROKEN; WIND 300 DEGS AT 10 KTS; GUSTS TO 20 KTS; OCCASIONALLY C20 BROKEN 2 MI; RAIN AND TSTMS WITH FRONTAL GUSTS AT 30 KTS. THE FLT WAS UNEVENTFUL UNTIL THE DSCNT PHASE. THE CURRENT DCA ATIS INFO RPTED THE SKY CONDITION AS 35 BROKEN 10 MI VISIBILITY; WINDS 180 DEGS AT 08 KTS WITH TSTMS IN THE AREA WITH RIVER VISUAL APCHS TO RWY 18 BEING CONDUCTED. DURING THE ARR INTO THE WASHINGTON AREA WE OBSERVED AN AREA OF WX RETURNS BTWN DULLES AND DCA. AS WE DSNDED INTO THE TERMINAL AREA; WE ENTERED AN AREA OF LIGHT RAIN SHOWERS THAT WERE SHOWING UP ON THE ALLIED SIGNAL AEROSPACE; BENDIX RDR-4B AIRBORNE WX RADAR AS AN AREA OF LIGHT GREEN RADAR RETURNS. AFTER SEVERAL MINS OF OP IN THE LIGHT RAIN; WHILE BEING VECTORED TO THE RIVER VISUAL FINAL APCH THE RADAR DISPLAY BEGAN TO SLOWLY ATTENUATE THE DISPLAY. WITHIN A FEW MINS; THE RADAR WX DISPLAY WAS NOT ABLE TO DISPLAY ANY USABLE STORM CELL INFO. THE RADAR DISPLAY INDICATED A SOLID AREA OF GREEN AND AMBER FROM THE RADOME OUT TO 30 MI WITH NOTHING BEING DISPLAYED BEYOND THAT RANGE. THIS DISPLAY WAS INDICATED IN ALL OF THE RADAR MODES; WX/TURB; MAP OR WX. THE USE OF MANUAL GAIN DID NOT ELIMINATE THIS ATTENUATION. WHILE TURNING ONTO THE FINAL APCH PATH; WHILE IN CONTINUOUS MODERATE TURB AND MODERATE RAIN SHOWERS; THE APCH CTLR INFORMED US THAT A PRECEDING FLT MISSED THE APCH AND INFORMED US THAT WE MIGHT HAVE BETTER LUCK WITH THE ROSSLYN LDA RWY 18. THE CTLR THEN CLRED US FOR THE ROSSLYN LDA RWY 18 APCH. SINCE THIS WAS THE FIRST WE HEARD THAT THE ROSSLYN LDA WAS IN USE; WE WERE VERY RUSHED PREPARING FOR THE APCH. SINCE WE WERE NOT ABLE TO DETERMINE THE LOCATION AND INTENSITY OF THE STORMS IN THE AREA WE DID NOT WANT TO EXECUTE A MISSED APCH TO ALLOW MORE TIME TO SET UP THE APCH. WE BROKE OUT OF THE OVCST APPROX 4 MI NW OF THE ARPT AND I BEGAN TO FOLLOW THE POTOMAC RIVER VISUALLY WHILE OPERATING IN MODERATE RAIN SHOWERS. DURING THE DSCNT; WHILE FOLLOWING THE RIVER; BOTH THE FO AND I HAD OUR WINDSHIELD WIPERS ON. THE A320- 232 HAS WINDSHIELD PRODUCED BY OTHER THAN OEM. THESE WINDSHIELDS ARE APPARENTLY MADE OF A SOFTER MATERIAL THAN THE STANDARD AIRBUS WINDSHIELD AND THESE WINDSHIELDS DEVELOP A PERMANENT BULGE IN THEM WITH PRESSURIZATION CYCLES. THIS BULGE IN THE WINDSHIELD DOES NOT ALLOW THE RUBBER WINDSHIELD WIPER BLADE TO PHYSICALLY TOUCH THE OUTER FOUR INCHES OF THE WIPER ARC. DUE THE POOR WATER REMOVAL FROM THE WINDOWS ALL THREE OF US IN THE COCKPIT WERE UNABLE TO KEEP THE ARPT IN SIGHT DURING THE VISUAL PORTION OF THE APCH. SINCE NO ONE HAD THE ARPT IN SIGHT I STOPPED THE DSCNT. SHORTLY THEREAFTER WE WERE NOT IN A POS TO CONTINUE THE APCH AND I RELUCTANTLY EXECUTED A MISSED APCH; CLBING BACK INTO AN AREA OF TSTMS WITHOUT AN OPERATIONAL WX RADAR UNIT. WE ATTEMPTED TO REMAIN IN VMC AND STAY OUT OF THE STORMS AS MUCH AS POSSIBLE. APCH THEN ADVISED US THAT THE WINDS HAD NOW SHIFTED TO 340 DEGS AT 22 KTS; GUSTS TO 28 KTS. WE SET UP FOR THE VOR RWY 36 DUE TO THE FACT THAT THE ILS WAS OTS. WE COMPLETED AN UNEVENTFUL LNDG ON RWY 36. THIS EXPERIENCE POINTS OUT SEVERAL PROBS. DCA NEEDS TO PUT MORE REALISTIC WX INFO ON THE ATIS. WE HAD 4 ACRS MISS THE APCH WHEN THE ATIS INDICATED IT WAS VFR WITH 10 MI VISIBILITY. APCH INFO NEEDS TO BE DISSEMINATED IN A MORE TIMELY MANNER. NONE OF THE INST APCHS TO RWY 18 AT DCA ARE LINE SELECTABLE IN THE FMC DATABASE. MINIMAL APCH LIGHT SYS FOR RWY 18 AT DCA. AIRBUS WINDSHIELD WIPERS NEED TO BE DESIGNED SO AS TO TOUCH THE WINDSHIELD. IS THAT TOO MUCH TO ASK FOR? THE KNOWN AIRBUS WX RADAR ATTENUATION AT LOW ALT WITH A WET RADOME NEEDS TO BE GIVEN HIGHPRIORITY TO BE FIXED. THE WX RADAR MANUFACTURER; ALLIED SIGNAL; PRODUCES A 40 MIN VIDEO TAPE ON THE USE OF ITS SYS ENTITLED 'PLT TRAINING; WX RADAR.' 13 MINS INTO THIS TRAINING TAPE; RADAR ATTENUATION IS FOR 2 MINS. THE TAPE INDICATES THAT RADAR ATTENUATION CAN BE CAUSED BY HVY SHEETS OF WATER OR ICE ON THE RADOME AND THAT THIS WILL INHIBIT THE PULSES OF RADAR ENERGY FROM BEING REFLECTED BACK TO THE RADAR RECEIVER AND WILL THUS CAUSE A RADAR SHADOW. THIS RADAR SHADOW RENDERS THE WX RADAR IMAGE USELESS IN THE DETERMINATION OF CELL LOCATION AND STRENGTH. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THIS RPTR WAS FLYING AN AIRBUS A320-232 EQUIPPED WITH AN ALLIED SIGNAL AEROSPACE; BENDIX RDR-48 AIRBORNE WX RADAR WHILE ON AN APCH IN LIGHT TO MODERATE RAIN AND RAIN SHOWERS. THE FLC WAS USING THEIR WINDSHIELD WIPERS DURING THE APCH ALSO. DURING A PERIOD OF LIGHT RAIN THE COLOR RADAR PICTURE BEGAN TO ATTENUATE AND IT TURNED SOLID GREEN WITH SOME AMBER ON THE SCREEN. THE RPTR SAID THAT THIS HAPPENS WHEN WATER OR ICE STAYS ON THE RADOME CAUSING INTERFERENCE WITH THE RETURNING SIGNAL. THE MANUFACTURER AND THE OPERATING AIRLINE HAVE KNOWN ABOUT THE PROB FOR MORE THAN A YR; HOWEVER; NO FIX HAS WORKED TO THIS DATE. THIS ATTENUATION PROB IS INTERMITTENT AND THE SAME CONDITIONS THAT AFFECTED THE RADAR ONCE MAY HAVE NO EFFECT AT ALL THE NEXT TIME. THE FLC THEN ENTERED MODERATE RAIN WHILE MANEUVERING ON THE RIVER VISUAL APCH. THEY REALIZED THAT THEY COULD ONLY SEE THROUGH A SMALL PORTION OF THE WINDSCREEN BECAUSE THE WIPERS WERE ONLY CONTACTING THAT PORTION. THIS IS BECAUSE THE WINDSCREENS ORDERED BY THIS COMPANY TEND TO BULGE FROM THE EFFECTS OF PRESSURIZATION. THIS ACFT HAD BEEN IN SVC ONLY ABOUT 15 HRS; ACCORDING TO THE RPTR; AND ALREADY HAD THE CHARACTERISTIC. THE RPTR SAID THAT THESE UNIQUE WINDSCREENS WERE MADE FOR HIS AIRLINE'S PARTICULAR ORDER AND NOBODY ELSE IS AFFECTED. AGAIN THE MANUFACTURER IS ATTEMPTING TO FIX THE PROB. THE SOLUTION; ACCORDING TO THE RPTR IS A MORE FLEXIBLE WINDSCREEN WIPER WHICH SHOULD BECOME AVAILABLE LATER THIS YR WHEN THE AIRLINE REMOVES THE CHEMICAL RAIN REMOVAL SYS FROM THE ACFT. IN THIS CASE; THE LACK OF FORWARD VISIBILITY CAUSED THE GAR; THE RPTR ALLEGED. THE LAST PROB AREA MENTIONED BY THE RPTR WAS THE LACK OF STORED APCH INFO FOR THE APCHS TO RWY 18. THIS; HE ADMITTED WAS A PROB FOR THE AIRLINE; BUT HE WANTED THE FAA AND THE CTLRS TO KNOW THAT IN THIS UNSTORED SIT; THE FLC EITHER HAS TO FLY THE APCH USING THE APCH PLATE ONLY OR TAKE THE TIME (WHICH WAS NOT AVAILABLE) AND ENTER EACH WAYPOINT INTO THE FMC. THE APCH PLATE ITSELF MUST BE BRIEFED AND THESE LAST MIN CHANGES CREATE A VERY HIGH WORKLOAD; HIGH STRESS; ENVIRONMENT IN THE COCKPIT.