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A B747 and a B757 are set up on a visual side-by approach to sfo runway's 28, told to maintain visual separation, cleared for the approach and cleared to tower frequency. The B747 starts approximately 300 ft behind the B757, but comes along side-by at approximately 500 ft. Tower local controller observes situation as B757 further reduces power for landing. Tower advises B747 to remain behind B757 and is told unable. Tower sends B757 around. B747 PIC states approach control should have made adjustments further out and planned for the B747 flight crew to remain behind the B757 in order to plan for the short final, reduced speed of the B757.
| Attributes | |
| ACN | 411852 |
| Time | |
| Date | 199808 |
| Day | Sun |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : sfo |
| State Reference | CA |
| Altitude | agl bound lower : 500 agl bound upper : 500 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : oak tower : sfo |
| Operator | common carrier : air carrier |
| Make Model Name | B747-400 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | descent : approach descent other landing other |
| Route In Use | approach : visual arrival other |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | B757 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | descent : approach landing : go around landing other |
| Route In Use | approach : visual arrival other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : flight engineer |
| Experience | flight time last 90 days : 100 flight time total : 14000 flight time type : 2000 |
| ASRS Report | 411852 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Events | |
| Anomaly | non adherence : clearance non adherence : published procedure other anomaly other |
| Independent Detector | other controllera other flight crewa |
| Resolutory Action | controller : issued new clearance other other |
| Consequence | Other |
Narrative:
Approach control (bay approach) asked us (flight from hkg to sfo) if we had a B757 in sight land on runway 28R. We replied that we did. Approach then said, 'the B757 has you in sight maintain visual separation cleared for the visual to runway 28L.' the 4 pilots in the cockpit discussed the clearance, in that was there a restr not to pass the B757. We concluded since there was no such statement that it was not part of clearance as long as we could maintain visual. The first officer flew the approach approximately 100 yds behind the B757 at minimum speed of 149 KTS until 500 ft AGL when the B757 slowed dramatically. Tower then called and said 'no not pass the B757.' this was the first time we heard that restr. At that point we were abeam the B757 and could not slow further. I told the tower that 'we were unable to comply.' the B757 was issued a go around clearance (wake turbulence issues). Note: if not passing an aircraft is so critical then I feel it should be stated in the clearance, and not assumed. I called the tower supervisor to suggest that approach make it clear what is required when 2 aircraft are on a visual approach to runways 28.
Original NASA ASRS Text
Title: A B747 AND A B757 ARE SET UP ON A VISUAL SIDE-BY APCH TO SFO RWY'S 28, TOLD TO MAINTAIN VISUAL SEPARATION, CLRED FOR THE APCH AND CLRED TO TWR FREQ. THE B747 STARTS APPROX 300 FT BEHIND THE B757, BUT COMES ALONG SIDE-BY AT APPROX 500 FT. TWR LCL CTLR OBSERVES SIT AS B757 FURTHER REDUCES PWR FOR LNDG. TWR ADVISES B747 TO REMAIN BEHIND B757 AND IS TOLD UNABLE. TWR SENDS B757 AROUND. B747 PIC STATES APCH CTL SHOULD HAVE MADE ADJUSTMENTS FURTHER OUT AND PLANNED FOR THE B747 FLC TO REMAIN BEHIND THE B757 IN ORDER TO PLAN FOR THE SHORT FINAL, REDUCED SPD OF THE B757.
Narrative: APCH CTL (BAY APCH) ASKED US (FLT FROM HKG TO SFO) IF WE HAD A B757 IN SIGHT LAND ON RWY 28R. WE REPLIED THAT WE DID. APCH THEN SAID, 'THE B757 HAS YOU IN SIGHT MAINTAIN VISUAL SEPARATION CLRED FOR THE VISUAL TO RWY 28L.' THE 4 PLTS IN THE COCKPIT DISCUSSED THE CLRNC, IN THAT WAS THERE A RESTR NOT TO PASS THE B757. WE CONCLUDED SINCE THERE WAS NO SUCH STATEMENT THAT IT WAS NOT PART OF CLRNC AS LONG AS WE COULD MAINTAIN VISUAL. THE FO FLEW THE APCH APPROX 100 YDS BEHIND THE B757 AT MINIMUM SPD OF 149 KTS UNTIL 500 FT AGL WHEN THE B757 SLOWED DRAMATICALLY. TWR THEN CALLED AND SAID 'NO NOT PASS THE B757.' THIS WAS THE FIRST TIME WE HEARD THAT RESTR. AT THAT POINT WE WERE ABEAM THE B757 AND COULD NOT SLOW FURTHER. I TOLD THE TWR THAT 'WE WERE UNABLE TO COMPLY.' THE B757 WAS ISSUED A GAR CLRNC (WAKE TURB ISSUES). NOTE: IF NOT PASSING AN ACFT IS SO CRITICAL THEN I FEEL IT SHOULD BE STATED IN THE CLRNC, AND NOT ASSUMED. I CALLED THE TWR SUPVR TO SUGGEST THAT APCH MAKE IT CLR WHAT IS REQUIRED WHEN 2 ACFT ARE ON A VISUAL APCH TO RWYS 28.
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.