Narrative:

We, air carrier a, were cleared for the 24R ILS to lax by approach control. WX at lax by latest ATIS as 12 0 8. WX during the approach, however, was overcast on final, approximately 1200-1400' MSL ceiling, tops 4000-4500'. We were told to hold 180 KIAS until romen (OM), then contact tower. This is the usual place aircraft contact tower on approachs into lax from the east. As we were configuring on final past romen and just breaking out of the WX at approximately 1200-1400' MSL, I noticed a rotating beacon at 3 O'clock position just coming out of the clouds. The aircraft was approximately 300-500' horizon and 100-200' above our aircraft, accelerating forward of us. My first reaction was to ask my captain to check who that was to our right since I was on approach (and on centerline) to 24R, the most northern runway at lax (coupled on autoplt and on G/south). The captain immediately, upon seeing the aircraft, asked tower who this aircraft was and where he was going. Tower responded that it was air carrier B and was flying a visibility approach to 24L. They again informed air carrier B that he was cleared to 24L, however air carrier B said that he thought he was cleared to 25R and we were for the left. Tower said no, air carrier a was for the right and air carrier B for the left. At this point, tower then seeing the best way out of this situation, asked if we had 24L in sight and cleared us to land on the left and air carrier to land on the right. On final, we were IMC from approximately 4000-4500' until 1200-1400'. In my opinion, air carrier B may have had us in sight and airport in sight when he was cleared for the visibility approach while north of the airport, but could not have maintained a visibility on us or the airport during the approach. If air carrier B had followed the localizer to 24R this situation could have been disastrous since he was at a higher speed than we--he may have descended into us from above. Once he lost sight of us or the airport, he should have immediately asked for vectors for an approach. Supplemental information from acn 109066: we were on a visibility approach to runway 24L from the north following an medium large transport from the east on an ILS straight in for 24R. He was in sight at 3500' when we accepted a visibility approach behind him. He then entered a cloud. While I could see his lights in the cloud I thought best to turn north of him and stay in the clear. The first officer working the radio had been changed over to the tower. We advised them we were to the north and ahead of our traffic. The tower cleared the other aircraft to land 24L and we were cleared to land 24R. Contributing factors: a few clouds east of the field; we could not see in the dark. How it was discovered: by observing aircraft enter clouds. Corrective actions: changed course to stay clear. I think it worked out ok.

Related reports:

Google
 

Original NASA ASRS Text

Title: WHILE ON FINAL APCH JUST BREAKING OUT OF CLOUDS MLG OBSERVED ANOTHER MLG IN CLOSE PROX SAME DIRECTION.

Narrative: WE, ACR A, WERE CLRED FOR THE 24R ILS TO LAX BY APCH CTL. WX AT LAX BY LATEST ATIS AS 12 0 8. WX DURING THE APCH, HOWEVER, WAS OVCST ON FINAL, APPROX 1200-1400' MSL CEILING, TOPS 4000-4500'. WE WERE TOLD TO HOLD 180 KIAS UNTIL ROMEN (OM), THEN CONTACT TWR. THIS IS THE USUAL PLACE ACFT CONTACT TWR ON APCHS INTO LAX FROM THE E. AS WE WERE CONFIGURING ON FINAL PAST ROMEN AND JUST BREAKING OUT OF THE WX AT APPROX 1200-1400' MSL, I NOTICED A ROTATING BEACON AT 3 O'CLOCK POS JUST COMING OUT OF THE CLOUDS. THE ACFT WAS APPROX 300-500' HORIZON AND 100-200' ABOVE OUR ACFT, ACCELERATING FORWARD OF US. MY FIRST REACTION WAS TO ASK MY CAPT TO CHK WHO THAT WAS TO OUR RIGHT SINCE I WAS ON APCH (AND ON CENTERLINE) TO 24R, THE MOST NORTHERN RWY AT LAX (COUPLED ON AUTOPLT AND ON G/S). THE CAPT IMMEDIATELY, UPON SEEING THE ACFT, ASKED TWR WHO THIS ACFT WAS AND WHERE HE WAS GOING. TWR RESPONDED THAT IT WAS ACR B AND WAS FLYING A VIS APCH TO 24L. THEY AGAIN INFORMED ACR B THAT HE WAS CLRED TO 24L, HOWEVER ACR B SAID THAT HE THOUGHT HE WAS CLRED TO 25R AND WE WERE FOR THE LEFT. TWR SAID NO, ACR A WAS FOR THE RIGHT AND ACR B FOR THE LEFT. AT THIS POINT, TWR THEN SEEING THE BEST WAY OUT OF THIS SITUATION, ASKED IF WE HAD 24L IN SIGHT AND CLRED US TO LAND ON THE LEFT AND ACR TO LAND ON THE RIGHT. ON FINAL, WE WERE IMC FROM APPROX 4000-4500' UNTIL 1200-1400'. IN MY OPINION, ACR B MAY HAVE HAD US IN SIGHT AND ARPT IN SIGHT WHEN HE WAS CLRED FOR THE VIS APCH WHILE N OF THE ARPT, BUT COULD NOT HAVE MAINTAINED A VIS ON US OR THE ARPT DURING THE APCH. IF ACR B HAD FOLLOWED THE LOC TO 24R THIS SITUATION COULD HAVE BEEN DISASTROUS SINCE HE WAS AT A HIGHER SPD THAN WE--HE MAY HAVE DSNDED INTO US FROM ABOVE. ONCE HE LOST SIGHT OF US OR THE ARPT, HE SHOULD HAVE IMMEDIATELY ASKED FOR VECTORS FOR AN APCH. SUPPLEMENTAL INFO FROM ACN 109066: WE WERE ON A VIS APCH TO RWY 24L FROM THE N FOLLOWING AN MLG FROM THE E ON AN ILS STRAIGHT IN FOR 24R. HE WAS IN SIGHT AT 3500' WHEN WE ACCEPTED A VIS APCH BEHIND HIM. HE THEN ENTERED A CLOUD. WHILE I COULD SEE HIS LIGHTS IN THE CLOUD I THOUGHT BEST TO TURN N OF HIM AND STAY IN THE CLEAR. THE F/O WORKING THE RADIO HAD BEEN CHANGED OVER TO THE TWR. WE ADVISED THEM WE WERE TO THE N AND AHEAD OF OUR TFC. THE TWR CLRED THE OTHER ACFT TO LAND 24L AND WE WERE CLRED TO LAND 24R. CONTRIBUTING FACTORS: A FEW CLOUDS E OF THE FIELD; WE COULD NOT SEE IN THE DARK. HOW IT WAS DISCOVERED: BY OBSERVING ACFT ENTER CLOUDS. CORRECTIVE ACTIONS: CHANGED COURSE TO STAY CLR. I THINK IT WORKED OUT OK.

Data retrieved from NASA's ASRS site as of August 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.