Narrative:

Working arrivals; VFR weather with very good visual approaches. The session was very busy with westerly winds complicating the situation. The bases were fast and compression on the final was substantial. Aircraft X requested an ILS autoland approach for currency. I cleared aircraft X at the marker for an ILS approach and assigned him 160 knots to 5 mile final. I brought aircraft Y behind him and slowed the aircraft down early to maintain wake turbulence separation. I cleared aircraft Y for the visual approach with 5.5 miles separation and assigned the flight 160 knots to 5 mile final and I instructed him to contact the tower. As I monitored the final I realized that aircraft Y was compressing too much on the heavy aircraft X; I immediately called the tower and I instructed them to break aircraft Y out to a 270 heading and to climb and maintain 4000 feet. Aircraft Y was still within the wake turbulence parameters at 5.01 NM behind the heavy. The local controller replied 'I think we have visual...hold on'; 5 second break then 'yes we have visual'. I let it go and it compressed further to 4.8 NM. As I thought about the situation and knowing that the tower controllers cannot waive wake turbulence separation unless the aircraft waives it with visual separation I was left wondering if that is what the tower meant. As this was a specific occurrence due to bad winds and compression I see no recommendation I can give. This was a very busy session with difficult winds; maybe there should have been a consideration to using a different runway.

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Original NASA ASRS Text

Title: TRACON Controller reported of two aircraft on final that were going to lose wake turbulence separation. TRACON Controller advised Tower Controller to break the trailing aircraft out and relayed go around instructions. Tower Controller advised TRACON Controller they would apply tower visual separation between the aircraft.

Narrative: Working Arrivals; VFR weather with very good visual approaches. The session was very busy with westerly winds complicating the situation. The bases were fast and compression on the final was substantial. Aircraft X requested an ILS autoland approach for currency. I cleared Aircraft X at the marker for an ILS approach and assigned him 160 knots to 5 mile final. I brought Aircraft Y behind him and slowed the aircraft down early to maintain Wake Turbulence separation. I cleared Aircraft Y for the visual approach with 5.5 miles separation and assigned the flight 160 knots to 5 mile final and I instructed him to contact the tower. As I monitored the final I realized that Aircraft Y was compressing too much on the heavy Aircraft X; I immediately called the tower and I instructed them to break Aircraft Y out to a 270 heading and to climb and maintain 4000 feet. Aircraft Y was still within the Wake Turbulence parameters at 5.01 NM behind the heavy. The local controller replied 'I think we have visual...hold on'; 5 second break then 'Yes we have visual'. I let it go and it compressed further to 4.8 NM. As I thought about the situation and knowing that the Tower controllers cannot waive wake turbulence separation unless the aircraft waives it with visual separation I was left wondering if that is what the tower meant. As this was a specific occurrence due to bad winds and compression I see no recommendation I can give. This was a very busy session with difficult winds; maybe there should have been a consideration to using a different runway.

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.