Narrative:

Approach to runway 24R while over (approaching) smo VOR during profile descent (from over fim VOR) was reclred almost immediately to 'depart smo heading 070 degrees and maintain 4000'.' was to be 'vectored to follow an mlt at 12-1 O'clock on the ILS 24L.' shortly thereafter we sighted the mlt approximately 5-6 mi east of romen LOM, which we reported. Lax approach (124.5 MHZ) then cleared us 'a visibility approach to runway 24R,' and specifically to 'follow' the mlt! This of course wasn't what we wanted, especially in interest of avoiding wake turbulence. We questioned approach if we could proceed the mlt on the visibility (as we felt we could easily stay a minimum of 3 mi in front of the mlt), but were quickly turned down! The captain had been working the radio as I was flying. I asked the captain if I could try a different approach with the controller, which he ok'd. So I asked: 'could we, in the interest of wake avoidance, fly so as to be above and along side the mlt?' the controller responded, 'you may fly about and north of the mlt on the visibility,' (runway 24L and right, 249 degree magnetic heading). We acknowledged and then asked for a comparison on speeds, which we were told the mlt was 20 KTS faster. So, based on this, I turned what I judged was a base turn approximately 1 1/2 mi ahead of the mlt so as to be just about 1/2 mi ahead of the mlt as we turned final (on a 35 degree converging course to final for 24R), ie: which with the 20 KTS greater speed, and us slowing further and configuring, would not only keep us north of the mlt, but completely out of his way while we kept him in sight. And, what I judged would be along side him also. But unfortunately it worked out we ended up about 3/4-1/2 mi ahead of the mlt, which I still felt would put us on about a 3 mi final. Evidently the mlt slowed more (when we first saw him he appeared completely configured). Anyway, we landed approximately 1/3 mi ahead of him. Upon taxiing in ground control asked us to call approach upon arrival (a controller named X). He was quite upset as he felt we purposely turned ahead against his instructions, which was to stay above and north, which I tried to explain was my intention, except for the mlt's unexpected slowing. After more talking he said he was satisfied and no further worry was needed. I hope he understood I was trying to keep us (87 of us) out of the wake while complying with his instructions, but unfortunately miscalculating the turn on. The captain expressed his support for my explanation while wishing we could talk one-on-one, face-to-face with the controller. Safety, I feel, was never a question--just my intentions in the mind of the controller.

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Original NASA ASRS Text

Title: AFTER BEING CLEARED FOR A VISUAL APCH, REPORTER ACFT PASSED ACFT BEING FOLLOWED ON APCH TO PARALLEL RWY.

Narrative: APCH TO RWY 24R WHILE OVER (APCHING) SMO VOR DURING PROFILE DSCNT (FROM OVER FIM VOR) WAS RECLRED ALMOST IMMEDIATELY TO 'DEPART SMO HDG 070 DEGS AND MAINTAIN 4000'.' WAS TO BE 'VECTORED TO FOLLOW AN MLT AT 12-1 O'CLOCK ON THE ILS 24L.' SHORTLY THEREAFTER WE SIGHTED THE MLT APPROX 5-6 MI E OF ROMEN LOM, WHICH WE RPTED. LAX APCH (124.5 MHZ) THEN CLRED US 'A VIS APCH TO RWY 24R,' AND SPECIFICALLY TO 'FOLLOW' THE MLT! THIS OF COURSE WASN'T WHAT WE WANTED, ESPECIALLY IN INTEREST OF AVOIDING WAKE TURB. WE QUESTIONED APCH IF WE COULD PROCEED THE MLT ON THE VIS (AS WE FELT WE COULD EASILY STAY A MINIMUM OF 3 MI IN FRONT OF THE MLT), BUT WERE QUICKLY TURNED DOWN! THE CAPT HAD BEEN WORKING THE RADIO AS I WAS FLYING. I ASKED THE CAPT IF I COULD TRY A DIFFERENT APCH WITH THE CTLR, WHICH HE OK'D. SO I ASKED: 'COULD WE, IN THE INTEREST OF WAKE AVOIDANCE, FLY SO AS TO BE ABOVE AND ALONG SIDE THE MLT?' THE CTLR RESPONDED, 'YOU MAY FLY ABOUT AND N OF THE MLT ON THE VIS,' (RWY 24L AND R, 249 DEG MAGNETIC HDG). WE ACKNOWLEDGED AND THEN ASKED FOR A COMPARISON ON SPDS, WHICH WE WERE TOLD THE MLT WAS 20 KTS FASTER. SO, BASED ON THIS, I TURNED WHAT I JUDGED WAS A BASE TURN APPROX 1 1/2 MI AHEAD OF THE MLT SO AS TO BE JUST ABOUT 1/2 MI AHEAD OF THE MLT AS WE TURNED FINAL (ON A 35 DEG CONVERGING COURSE TO FINAL FOR 24R), IE: WHICH WITH THE 20 KTS GREATER SPD, AND US SLOWING FURTHER AND CONFIGURING, WOULD NOT ONLY KEEP US N OF THE MLT, BUT COMPLETELY OUT OF HIS WAY WHILE WE KEPT HIM IN SIGHT. AND, WHAT I JUDGED WOULD BE ALONG SIDE HIM ALSO. BUT UNFORTUNATELY IT WORKED OUT WE ENDED UP ABOUT 3/4-1/2 MI AHEAD OF THE MLT, WHICH I STILL FELT WOULD PUT US ON ABOUT A 3 MI FINAL. EVIDENTLY THE MLT SLOWED MORE (WHEN WE FIRST SAW HIM HE APPEARED COMPLETELY CONFIGURED). ANYWAY, WE LANDED APPROX 1/3 MI AHEAD OF HIM. UPON TAXIING IN GND CTL ASKED US TO CALL APCH UPON ARR (A CTLR NAMED X). HE WAS QUITE UPSET AS HE FELT WE PURPOSELY TURNED AHEAD AGAINST HIS INSTRUCTIONS, WHICH WAS TO STAY ABOVE AND N, WHICH I TRIED TO EXPLAIN WAS MY INTENTION, EXCEPT FOR THE MLT'S UNEXPECTED SLOWING. AFTER MORE TALKING HE SAID HE WAS SATISFIED AND NO FURTHER WORRY WAS NEEDED. I HOPE HE UNDERSTOOD I WAS TRYING TO KEEP US (87 OF US) OUT OF THE WAKE WHILE COMPLYING WITH HIS INSTRUCTIONS, BUT UNFORTUNATELY MISCALCULATING THE TURN ON. THE CAPT EXPRESSED HIS SUPPORT FOR MY EXPLANATION WHILE WISHING WE COULD TALK ONE-ON-ONE, FACE-TO-FACE WITH THE CTLR. SAFETY, I FEEL, WAS NEVER A QUESTION--JUST MY INTENTIONS IN THE MIND OF THE CTLR.

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.