Air carrier descending for sfo with ZOA reported a TCAS TA event with opposite direction climbing tr...

Attributes
ACN	938384
Time
Date	201103
Local Time Of Day	0601-1200
Place
Locale Reference	ZOA.ARTCC
State Reference	CA
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Climb
Person 1
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 140 Flight Crew Total 22000 Flight Crew Type 5800
Person 2
Function	First Officer Pilot Flying
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 22000 Flight Crew Type 6000
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict

Narrative:

ATC delayed our request for lower even though we were expected to cross pirat at 8;000; and were at 35;000; 49 NM from pirat. At the last minute; ATC cleared us to 8;000; and we advised that we'd be hard pressed to make the crossing restriction. A high rate of descent with speed brakes fully deployed was initiated by the flying first officer. Passing 30;400; with a rate of descent greater than 6;000 FPM; ATC changed our clearance to 'maintain FL300' smoothly leveling off and re-climbing to FL300; we advised ATC that we were at FL29.4; climbing back to FL300. At this point we got a TA advisory on the TCAS and saw an air carrier at our 12 o'clock position; about 1 1/2 miles; opposite direction; at FL290. ATC was advised; we were instructed to do a 360; then descend to 8;000; direct pirat; sau. This could have been a tragic midair with a less experienced crew.

Original NASA ASRS Text

Title: Air Carrier descending for SFO with ZOA reported a TCAS TA event with opposite direction climbing traffic with minimal separation; ATC issued a 360 degree turn after being advised about the developing conflict.

Narrative: ATC delayed our request for lower even though we were expected to cross PIRAT at 8;000; and were at 35;000; 49 NM from PIRAT. At the last minute; ATC cleared us to 8;000; and we advised that we'd be hard pressed to make the crossing restriction. A high rate of descent with speed brakes fully deployed was initiated by the flying First Officer. Passing 30;400; with a rate of descent greater than 6;000 FPM; ATC changed our clearance to 'Maintain FL300' smoothly leveling off and re-climbing to FL300; we advised ATC that we were at FL29.4; climbing back to FL300. At this point we got a TA advisory on the TCAS and saw an air carrier at our 12 o'clock position; about 1 1/2 miles; opposite direction; at FL290. ATC was advised; we were instructed to do a 360; then descend to 8;000; direct PIRAT; SAU. This could have been a tragic midair with a less experienced crew.

Data retrieved from NASA's ASRS site as of April 2012 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.

Air carrier descending for sfo with ZOA reported a TCAS TA event with opposite direction climbing traffic with minimal separation; ATC issued a 360 degree turn after being advised about the developing conflict.