Narrative:

I was the PF from myr to rdu. We had a high pitch squeeling sound at 4.5 psi at 10000 ft at cruise. The captain was on communication #2 talking to maintenance while I checked in with rdu approach. I was told to expect runway 23L and given a frequency change. I was waiting for a break in frequency congestion on the new frequency when the captain said he was back on communication #1. He checked in and we were cleared to 6000 ft. We were then cleared to 4000 ft and given a heading of 320 degrees. An medium large transport at 10:30 - 11 O'clock position on a right base to runway 23R was pointed out and our runway was switched to runway 23R. The captain reported the medium large transport in sight and we were cleared for the visual approach to runway 23R and told to maintain visual contact with the medium large transport. Then another voice on rdu approach said 'you can descend from 4000 ft to 2000 ft if you want.' this nonstandard terminology made me wonder why, if in fact we were already cleared for the visual approach, were we given a new altitude. It sounded like there was some confusion in this voice and there was possibly more than 1 controller on this frequency. At this time I lost visual contact with the medium large transport so I flew through final to avoid a potential midair collision with the medium large transport. I attempted to tell the captain I had lost sight of the medium large transport when the captain told me he had lost sight of our traffic. There was a haze layer at our altitude while looking to the west into the sun. The captain was unable to notify ATC that we had lost sight of the traffic because there was some frequency congestion. I noticed a widebody transport at 12 O'clock and 3 mi that appeared to be at 4000 ft. I increased my descent rate through 3000 ft and turned back toward final. Then we received an RA on the TCASII. The TCASII advisory commanded a descent so I further increased my descent, then the clear of conflict voice came on. During this time the captain was unable to advise ATC that we had lost sight of the medium large transport because ATC was advising us of the widebody transport traffic. ATC followed by giving the widebody transport alternate instructions to increase the space between us. This widebody transport had previously been cleared to follow us on a visual to runway 23R. I made a normal landing and exited the runway as expeditiously as possible. The widebody transport also made a normal landing. Frequency congestion, ATC position change, backgnd noise created by communication #2, glaring sun and haze on final, different types of head sets and microphones, fatigue created by 4 days of flying, wake turbulence, position of GS antenna on an medium large transport, are all contributing factors. This situation involved many human and mechanical factors that are affected by many variables. I believe that the TCASII is the major factor that prevented a near miss.

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Original NASA ASRS Text

Title: LTT FO, PF, LOSES SIGHT OF TFC SIGHTED DURING VISUAL APCH PROC AND EXECUTES A HDG TRACK DEV IN REMAINDER OF APCH, ENCOUNTERING A TCASII RA ENRTE.

Narrative: I WAS THE PF FROM MYR TO RDU. WE HAD A HIGH PITCH SQUEELING SOUND AT 4.5 PSI AT 10000 FT AT CRUISE. THE CAPT WAS ON COM #2 TALKING TO MAINT WHILE I CHKED IN WITH RDU APCH. I WAS TOLD TO EXPECT RWY 23L AND GIVEN A FREQ CHANGE. I WAS WAITING FOR A BREAK IN FREQ CONGESTION ON THE NEW FREQ WHEN THE CAPT SAID HE WAS BACK ON COM #1. HE CHKED IN AND WE WERE CLRED TO 6000 FT. WE WERE THEN CLRED TO 4000 FT AND GIVEN A HDG OF 320 DEGS. AN MLG AT 10:30 - 11 O'CLOCK POS ON A R BASE TO RWY 23R WAS POINTED OUT AND OUR RWY WAS SWITCHED TO RWY 23R. THE CAPT RPTED THE MLG IN SIGHT AND WE WERE CLRED FOR THE VISUAL APCH TO RWY 23R AND TOLD TO MAINTAIN VISUAL CONTACT WITH THE MLG. THEN ANOTHER VOICE ON RDU APCH SAID 'YOU CAN DSND FROM 4000 FT TO 2000 FT IF YOU WANT.' THIS NONSTANDARD TERMINOLOGY MADE ME WONDER WHY, IF IN FACT WE WERE ALREADY CLRED FOR THE VISUAL APCH, WERE WE GIVEN A NEW ALT. IT SOUNDED LIKE THERE WAS SOME CONFUSION IN THIS VOICE AND THERE WAS POSSIBLY MORE THAN 1 CTLR ON THIS FREQ. AT THIS TIME I LOST VISUAL CONTACT WITH THE MLG SO I FLEW THROUGH FINAL TO AVOID A POTENTIAL MIDAIR COLLISION WITH THE MLG. I ATTEMPTED TO TELL THE CAPT I HAD LOST SIGHT OF THE MLG WHEN THE CAPT TOLD ME HE HAD LOST SIGHT OF OUR TFC. THERE WAS A HAZE LAYER AT OUR ALT WHILE LOOKING TO THE W INTO THE SUN. THE CAPT WAS UNABLE TO NOTIFY ATC THAT WE HAD LOST SIGHT OF THE TFC BECAUSE THERE WAS SOME FREQ CONGESTION. I NOTICED A WDB AT 12 O'CLOCK AND 3 MI THAT APPEARED TO BE AT 4000 FT. I INCREASED MY DSCNT RATE THROUGH 3000 FT AND TURNED BACK TOWARD FINAL. THEN WE RECEIVED AN RA ON THE TCASII. THE TCASII ADVISORY COMMANDED A DSCNT SO I FURTHER INCREASED MY DSCNT, THEN THE CLR OF CONFLICT VOICE CAME ON. DURING THIS TIME THE CAPT WAS UNABLE TO ADVISE ATC THAT WE HAD LOST SIGHT OF THE MLG BECAUSE ATC WAS ADVISING US OF THE WDB TFC. ATC FOLLOWED BY GIVING THE WDB ALTERNATE INSTRUCTIONS TO INCREASE THE SPACE BTWN US. THIS WDB HAD PREVIOUSLY BEEN CLRED TO FOLLOW US ON A VISUAL TO RWY 23R. I MADE A NORMAL LNDG AND EXITED THE RWY AS EXPEDITIOUSLY AS POSSIBLE. THE WDB ALSO MADE A NORMAL LNDG. FREQ CONGESTION, ATC POS CHANGE, BACKGND NOISE CREATED BY COM #2, GLARING SUN AND HAZE ON FINAL, DIFFERENT TYPES OF HEAD SETS AND MICROPHONES, FATIGUE CREATED BY 4 DAYS OF FLYING, WAKE TURB, POS OF GS ANTENNA ON AN MLG, ARE ALL CONTRIBUTING FACTORS. THIS SIT INVOLVED MANY HUMAN AND MECHANICAL FACTORS THAT ARE AFFECTED BY MANY VARIABLES. I BELIEVE THAT THE TCASII IS THE MAJOR FACTOR THAT PREVENTED A NEAR MISS.

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.