2 aircraft crossing. Controller descended 1 aircraft and lost standard separation.

Attributes
ACN	147075
Time
Date	199005
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : rke
State Reference	CA
Altitude	msl bound lower : 25000 msl bound upper : 26000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	Heavy Transport, Low Wing, 4 Turbojet Eng
Flight Phase	descent other
Route In Use	arrival star : star
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Military Trainer
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 4
ASRS Report	147075
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 18000 vertical : 500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was working an inbound/outbnd high altitude sector. Heavy transport was southbound on baret 3 arrival to san airport. MTR was eastbound at FL250. I descended heavy transport to FL240 thinking the heavy transport needed to have lower altitude landing san. When heavy transport was descending through FL262 I realized that required sep was not ensured. I turned MTR nebnd and climbed him to FL270. I expedited heavy transport's descend to FL240. I could not turn heavy transport to the left because R2507 was in use at the time. Required sep was lost.

Original NASA ASRS Text

Title: 2 ACFT CROSSING. CTLR DESCENDED 1 ACFT AND LOST STANDARD SEPARATION.

Narrative: I WAS WORKING AN INBND/OUTBND HIGH ALT SECTOR. HVT WAS SBND ON BARET 3 ARR TO SAN ARPT. MTR WAS EBND AT FL250. I DSNDED HVT TO FL240 THINKING THE HVT NEEDED TO HAVE LOWER ALT LNDG SAN. WHEN HVT WAS DSNDING THROUGH FL262 I REALIZED THAT REQUIRED SEP WAS NOT ENSURED. I TURNED MTR NEBND AND CLBED HIM TO FL270. I EXPEDITED HVT'S DSND TO FL240. I COULD NOT TURN HVT TO THE LEFT BECAUSE R2507 WAS IN USE AT THE TIME. REQUIRED SEP WAS LOST.

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.