ZSE controller witnessed minimum separation event with two opposite direction aircraft with closure ...

Attributes
ACN	864002
Time
Date	200912
Local Time Of Day	0001-0600
Place
Locale Reference	ZSE.ARTCC
State Reference	WA
Aircraft 1
Make Model Name	Piper Twin Turboprop Undifferentiated or Other Model
Operating Under FAR Part	Part 135
Flight Phase	Cruise
Route In Use	None
Flight Plan	IFR
Aircraft 2
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Other Instrument Approach
Flight Plan	IFR
Person 1
Function	Supervisor / CIC
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Procedural Published Material / Policy

Narrative:

Aircraft X was in level flight at 150 direct to sfo. Aircraft Y was leaving FL185; the data block showing aircraft Y descending to 10;000 MSL. These aircraft were nose to nose; with a 600 KT closure rate less than 20 NM apart. The ZSE R30 controller asked ZOA sector 42 if he was aware of the pending situation. The ZOA controller responded the he would get aircraft Y below the other aircraft. When aircraft Y left 140 when there was no more than 5 NM separation. This situation was very hard to watch and the ZSE sector 30 controller acted appropriately by asking ZOA what they were doing. Recommendation; teach ZOA controllers that running minimum separation; when aircraft are on nose to nose courses and merging; is unacceptable.

Original NASA ASRS Text

Title: ZSE controller witnessed minimum separation event with two opposite direction aircraft with closure rates in the 600 KT range; reporter indicating ZOA controller was using unacceptable separation practices.

Narrative: Aircraft X was in level flight at 150 direct to SFO. Aircraft Y was leaving FL185; the data block showing Aircraft Y descending to 10;000 MSL. These aircraft were nose to nose; with a 600 KT closure rate less than 20 NM apart. The ZSE R30 controller asked ZOA Sector 42 if he was aware of the pending situation. The ZOA controller responded the he would get Aircraft Y below the other aircraft. When Aircraft Y left 140 when there was no more than 5 NM separation. This situation was very hard to watch and the ZSE Sector 30 controller acted appropriately by asking ZOA what they were doing. Recommendation; teach ZOA controllers that running minimum separation; when aircraft are on nose to nose courses and merging; is unacceptable.

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.