Narrative:

On arrival into lax we were being vectored off of the VISTA2 behind a 747 for a visual approach to 25L. Approach asked if we had the preceding heavy 747 in sight. We acknowledged that we did and were subsequently cleared for the visual approach to 25L; caution wake turbulence. We were on a base leg and the 747 was on final at 12 o'clock and approximately 4 miles so we continued on the base leg to square off the intercept in order to create sufficient clearance for wake turbulence. However a few moments after clearing us for the visual and us taking responsibility for wake turbulence the controller instructed us to turn left 280 for the intercept. We made the turn but were now closer than we felt comfortable and proceeded with plan b for wake avoidance and flew the approach above the 747's approach path. We both noted the quartering tailwind and in spite of descending slightly above profile had intermittent wake encounters. Nothing violent; but better described as light turbulence or dirty air. As we approached the 500 ft gate we felt that the air was too unstable to continue the approach and initiated the go around. Shortly before our decision to go around the controller issued a takeoff clearance to a heavy on 25R. We were climbing out on runway heading while the heavy was climbing out on an RNAV (wind corrected) track. I pointed out the heavy at 1 o'clock and perhaps a quarter to a half mile to the captain and we agreed that we did not like how this was developing as the crosswind was drifting us towards the heavy. As we were leveling off at 2;000 ft the tower controller issued a left turn to the proceeding heavy which had him turning directly into our path. As the heavy went wing up in the turn the controller gave us a left turn away from the heavy. The controller then switched us over to approach control. The approach controller climbed us and vectored us around for another visual where we completed an uneventful landing.several aspects of the approach and the missed bothered both of us; and we both agreed that we are seeing more and more of these occurrences. The first is being cleared for a visual approach and then after being cleared for the visual being issued a vector. While most of the time this results in no harm it does create ambiguity. Because by accepting the visual we are responsible for maneuvering ourselves for a stabilized approach and/or for spacing on the preceding aircraft and yet the controller is chipping away at our intercept that we need for a stabilized visual or worse chipping away at our spacing with the preceding aircraft - which we are now responsible for. The second issue is launching aircraft on an RNAV departure with an aircraft on a visual approach to the parallel runway. In the event of a go around the aircraft on the visual is flying a heading while the aircraft on departure is on a wind corrected RNAV track. This can create a dangerous situation on its own. The third issue; and perhaps the most dangerous; is issuing a clearance to an aircraft before issuing a clearance to the aircraft that could be endangered. For example; ground control telling a taxiing aircraft that other traffic will give way before telling those aircraft to give way - I hear this constantly. In this instance the preceding heavy was given a turn toward us before we were given a turn to remain clear. It is out of order and could lead to another tenerife. All it takes is a stuck mic; a blocked transmission; or missed radio call and the chain of events is in motion.

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Original NASA ASRS Text

Title: A320 First Officer reported executing a go-around after encountering wake turbulence in trail of a B747 on approach to LAX.

Narrative: On arrival into LAX we were being vectored off of the VISTA2 behind a 747 for a visual approach to 25L. Approach asked if we had the preceding heavy 747 in sight. We acknowledged that we did and were subsequently cleared for the visual approach to 25L; caution wake turbulence. We were on a base leg and the 747 was on final at 12 o'clock and approximately 4 miles so we continued on the base leg to square off the intercept in order to create sufficient clearance for wake turbulence. However a few moments after clearing us for the visual and us taking responsibility for wake turbulence the controller instructed us to turn left 280 for the intercept. We made the turn but were now closer than we felt comfortable and proceeded with plan b for wake avoidance and flew the approach above the 747's approach path. We both noted the quartering tailwind and in spite of descending slightly above profile had intermittent wake encounters. Nothing violent; but better described as light turbulence or dirty air. As we approached the 500 ft gate we felt that the air was too unstable to continue the approach and initiated the go around. Shortly before our decision to go around the controller issued a takeoff clearance to a heavy on 25R. We were climbing out on runway heading while the heavy was climbing out on an RNAV (wind corrected) track. I pointed out the heavy at 1 o'clock and perhaps a quarter to a half mile to the Captain and we agreed that we did not like how this was developing as the crosswind was drifting us towards the heavy. As we were leveling off at 2;000 ft the tower controller issued a left turn to the proceeding heavy which had him turning directly into our path. As the heavy went wing up in the turn the controller gave us a left turn away from the heavy. The controller then switched us over to Approach Control. The Approach Controller climbed us and vectored us around for another visual where we completed an uneventful landing.Several aspects of the approach and the missed bothered both of us; and we both agreed that we are seeing more and more of these occurrences. The first is being cleared for a visual approach and then after being cleared for the visual being issued a vector. While most of the time this results in no harm it does create ambiguity. Because by accepting the visual we are responsible for maneuvering ourselves for a stabilized approach and/or for spacing on the preceding aircraft and yet the controller is chipping away at our intercept that we need for a stabilized visual or worse chipping away at our spacing with the preceding aircraft - which we are now responsible for. The second issue is launching aircraft on an RNAV departure with an aircraft on a visual approach to the parallel runway. In the event of a go around the aircraft on the visual is flying a heading while the aircraft on departure is on a wind corrected RNAV track. This can create a dangerous situation on its own. The third issue; and perhaps the most dangerous; is issuing a clearance to an aircraft BEFORE issuing a clearance to the aircraft that could be endangered. For example; Ground Control telling a taxiing aircraft that other traffic will give way before telling those aircraft to give way - I hear this constantly. In this instance the preceding heavy was given a turn toward us before we were given a turn to remain clear. It is out of order and could lead to another Tenerife. All it takes is a stuck mic; a blocked transmission; or missed radio call and the chain of events is in motion.

Data retrieved from NASA's ASRS site 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.