B767 flight crew makes evasive maneuver to follow traffic causing aircraft to question sequencing.

Attributes
ACN	510057
Time
Date	200105
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sfo.airport
State Reference	CA
Altitude	msl bound lower : 1800 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : o90.tracon tower : sfo.tower tracon : azo.tracon
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : o90.tracon tower : sfo.tower
Operator	common carrier : air carrier
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	arrival star : ns
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 : 120 flight time total : 12200 flight time type : 700
ASRS Report	510027
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : airborne critical non adherence : required legal separation other anomaly other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	controller : issued advisory flight crew : took precautionary avoidance action flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Airspace Structure Flight Crew Human Performance Airport ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

Given clearance to expect FMS arrival to runway 28R with clearance direct to archi, maintain 7000 ft. ATC put a B777 in front of us, apparently short-cutting arrival. We were now receiving numerous xcourse vectors and progressive descent clearance to gain spacing this causes confusion in aircraft behind us that was told to follow us. On last vector, cleared to continue approach, we got TCASII TA and then RA on B737-800 on approach for runway 28L. RA gave us descent command of 2000 FPM at 2000 ft MSL. It finally stopped at 1800 ft MSL. Additionally, approach winds were 360 degrees at 24 KTS. On ground, ATC admitted it was probably a mistake to put B777 in. Sfo is bad enough coming into on a good day. It was a hazardous environment today. The push for capacity seems to be making safety take a back seat.

Original NASA ASRS Text

Title: B767 FLC MAKES EVASIVE MANEUVER TO FOLLOW TFC CAUSING ACFT TO QUESTION SEQUENCING.

Narrative: GIVEN CLRNC TO EXPECT FMS ARR TO RWY 28R WITH CLRNC DIRECT TO ARCHI, MAINTAIN 7000 FT. ATC PUT A B777 IN FRONT OF US, APPARENTLY SHORT-CUTTING ARR. WE WERE NOW RECEIVING NUMEROUS XCOURSE VECTORS AND PROGRESSIVE DSCNT CLRNC TO GAIN SPACING THIS CAUSES CONFUSION IN ACFT BEHIND US THAT WAS TOLD TO FOLLOW US. ON LAST VECTOR, CLRED TO CONTINUE APCH, WE GOT TCASII TA AND THEN RA ON B737-800 ON APCH FOR RWY 28L. RA GAVE US DSCNT COMMAND OF 2000 FPM AT 2000 FT MSL. IT FINALLY STOPPED AT 1800 FT MSL. ADDITIONALLY, APCH WINDS WERE 360 DEGS AT 24 KTS. ON GND, ATC ADMITTED IT WAS PROBABLY A MISTAKE TO PUT B777 IN. SFO IS BAD ENOUGH COMING INTO ON A GOOD DAY. IT WAS A HAZARDOUS ENVIRONMENT TODAY. THE PUSH FOR CAPACITY SEEMS TO BE MAKING SAFETY TAKE A BACK SEAT.

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.