Narrative:

We were on a visual approach to runway 25L at lax. When we switched to tower we were changed to and cleared to land on runway 25R. At this point we received a TCASII TA indicating an intruder at 2-3 O'clock at 1 mi. We visually sighted a learjet from the north pass in front of us and line up on the runway 25L final. I asked lax tower about this aircraft. Tower indicated it was an overshoot from the north complex. In my opinion, this aircraft confused runway 25L as runway 24L at lax. Compounding this problem was that the learjet was on the wrong communication frequency and was not communicating with any ground station. Shortly after this, the learjet suddenly changed from runway 25L to runway 25R. It was now 1/2 - 1 mi ahead of me for my runway. I told tower of this and tower canceled my approach clearance and instructed me to climb to 2000 ft MSL. Then the learjet, at about 200 ft AGL above runway 25R, began his own missed approach. I told the tower the lear was executing a go around. Tower asked if I could still land on runway 25R. I indicated I could and landed without incident. Landing was definitely the best choice because it kept me behind and away from this unpredictable 'lost communication' jet. Tower later thanked us for our performance and vigilance in this highly irregular situation.

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Original NASA ASRS Text

Title: ACFT #1 WAS ESTABLISHED ON APCH, RECEIVED A TCASII TA. ACFT #2 PASSED IN FRONT OF ACFT #1 AND LINED UP ON THE WRONG RWY. BOTH ACFT BEGAN A MISSED APCH. ACFT #1 DETERMINED IT SAFER TO LAND AND MAINTAINED AN IN TRAIL SEPARATION.

Narrative: WE WERE ON A VISUAL APCH TO RWY 25L AT LAX. WHEN WE SWITCHED TO TWR WE WERE CHANGED TO AND CLRED TO LAND ON RWY 25R. AT THIS POINT WE RECEIVED A TCASII TA INDICATING AN INTRUDER AT 2-3 O'CLOCK AT 1 MI. WE VISUALLY SIGHTED A LEARJET FROM THE N PASS IN FRONT OF US AND LINE UP ON THE RWY 25L FINAL. I ASKED LAX TWR ABOUT THIS ACFT. TWR INDICATED IT WAS AN OVERSHOOT FROM THE N COMPLEX. IN MY OPINION, THIS ACFT CONFUSED RWY 25L AS RWY 24L AT LAX. COMPOUNDING THIS PROB WAS THAT THE LEARJET WAS ON THE WRONG COM FREQ AND WAS NOT COMMUNICATING WITH ANY GND STATION. SHORTLY AFTER THIS, THE LEARJET SUDDENLY CHANGED FROM RWY 25L TO RWY 25R. IT WAS NOW 1/2 - 1 MI AHEAD OF ME FOR MY RWY. I TOLD TWR OF THIS AND TWR CANCELED MY APCH CLRNC AND INSTRUCTED ME TO CLB TO 2000 FT MSL. THEN THE LEARJET, AT ABOUT 200 FT AGL ABOVE RWY 25R, BEGAN HIS OWN MISSED APCH. I TOLD THE TWR THE LEAR WAS EXECUTING A GAR. TWR ASKED IF I COULD STILL LAND ON RWY 25R. I INDICATED I COULD AND LANDED WITHOUT INCIDENT. LNDG WAS DEFINITELY THE BEST CHOICE BECAUSE IT KEPT ME BEHIND AND AWAY FROM THIS UNPREDICTABLE 'LOST COM' JET. TWR LATER THANKED US FOR OUR PERFORMANCE AND VIGILANCE IN THIS HIGHLY IRREGULAR SIT.

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.