Narrative:

On socal approach frequency 128.5 at XA50 local, approach cleared us for a visual approach to runway 24R, behind a B747. The B747 was for runway 24L, 1/4 mi ahead. The frequency was busy and the controller did not hear our request to fly the visual in front of the heavy. Runway 24L/right are too close together to fly parallel visual approachs without adequate wake turbulence separation. I queried the controller again and stated that we needed to be in front of the heavy or 5 mi in trail. He said, and I quote, 'we do it all the time.' he then handed us off to tower, avoiding the responsibility. Well, I do not do it all the time. We were 1/4 mi in trail and above so we elected to pass and fly slightly ahead of the B747. When switching to tower (133.9) she said do not pass, after we had already done so. She then assumed responsibility for separation. Lax doesn't usually fly parallel visuals to runway 24L/right. This was an unusual situation, but definitely an unsafe practice. Wake turbulence separation is not something to make light of, especially when flying a B737. The controller's response was inexcusable. In reality he was too busy to provide adequate separation and could have been very bad if I had not been proactive. Callback conversation with reporter revealed the following information: reporter stated that they were in trail to the B747 on a downwind when the B747 was turned toward the airport for a visual approach but reported they did not see the airport. The reporter thought the controller then put the B747 on the ILS for runway 24L and then asked the reporter to report the airport and the B747 in sight while turning a base leg for runway 24R. Reporter indicated wake turbulence separation was lost when they turned base leg and that they were about 1 DOT high on the GS to avoid the wake turbulence. Reporter received a wake turbulence advisory when they were initially put in trail to the B747. Reporter stated the B747 flight crew were advised of reporter's aircraft but did not report it in sight. Reporter alleges the charted visual approach procedures are not being used.

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Original NASA ASRS Text

Title: RPTR ALLEGES LOSS OF WAKE TURB SEPARATION BEHIND A B747 ONE QUARTER MI AHEAD WHEN GIVEN A VISUAL APCH TO THE PARALLEL RWY. OPERROR.

Narrative: ON SOCAL APCH FREQ 128.5 AT XA50 LCL, APCH CLRED US FOR A VISUAL APCH TO RWY 24R, BEHIND A B747. THE B747 WAS FOR RWY 24L, 1/4 MI AHEAD. THE FREQ WAS BUSY AND THE CTLR DID NOT HEAR OUR REQUEST TO FLY THE VISUAL IN FRONT OF THE HVY. RWY 24L/R ARE TOO CLOSE TOGETHER TO FLY PARALLEL VISUAL APCHS WITHOUT ADEQUATE WAKE TURB SEPARATION. I QUERIED THE CTLR AGAIN AND STATED THAT WE NEEDED TO BE IN FRONT OF THE HVY OR 5 MI IN TRAIL. HE SAID, AND I QUOTE, 'WE DO IT ALL THE TIME.' HE THEN HANDED US OFF TO TWR, AVOIDING THE RESPONSIBILITY. WELL, I DO NOT DO IT ALL THE TIME. WE WERE 1/4 MI IN TRAIL AND ABOVE SO WE ELECTED TO PASS AND FLY SLIGHTLY AHEAD OF THE B747. WHEN SWITCHING TO TWR (133.9) SHE SAID DO NOT PASS, AFTER WE HAD ALREADY DONE SO. SHE THEN ASSUMED RESPONSIBILITY FOR SEPARATION. LAX DOESN'T USUALLY FLY PARALLEL VISUALS TO RWY 24L/R. THIS WAS AN UNUSUAL SIT, BUT DEFINITELY AN UNSAFE PRACTICE. WAKE TURB SEPARATION IS NOT SOMETHING TO MAKE LIGHT OF, ESPECIALLY WHEN FLYING A B737. THE CTLR'S RESPONSE WAS INEXCUSABLE. IN REALITY HE WAS TOO BUSY TO PROVIDE ADEQUATE SEPARATION AND COULD HAVE BEEN VERY BAD IF I HAD NOT BEEN PROACTIVE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THEY WERE IN TRAIL TO THE B747 ON A DOWNWIND WHEN THE B747 WAS TURNED TOWARD THE ARPT FOR A VISUAL APCH BUT RPTED THEY DID NOT SEE THE ARPT. THE RPTR THOUGHT THE CTLR THEN PUT THE B747 ON THE ILS FOR RWY 24L AND THEN ASKED THE RPTR TO RPT THE ARPT AND THE B747 IN SIGHT WHILE TURNING A BASE LEG FOR RWY 24R. RPTR INDICATED WAKE TURB SEPARATION WAS LOST WHEN THEY TURNED BASE LEG AND THAT THEY WERE ABOUT 1 DOT HIGH ON THE GS TO AVOID THE WAKE TURB. RPTR RECEIVED A WAKE TURB ADVISORY WHEN THEY WERE INITIALLY PUT IN TRAIL TO THE B747. RPTR STATED THE B747 FLC WERE ADVISED OF RPTR'S ACFT BUT DID NOT RPT IT IN SIGHT. RPTR ALLEGES THE CHARTED VISUAL APCH PROCS ARE NOT BEING USED.

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.