ZLA controller experienced operational error at FL260 when climbing aircraft above cruise aircraft.

Attributes
ACN	628239
Time
Date	200408
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : gmn.vortac
State Reference	CA
Altitude	msl single value : 26000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc tower : atl.tower
Operator	common carrier : air taxi
Make Model Name	Beechcraft Twin Turboprop Jet Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 5 controller time certified in position1 : 2 controller time certified in position2 : 6
ASRS Report	628239
Person 2
Affiliation	company : air taxi
Function	flight crew : single pilot
Events
Anomaly	non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera
Resolutory Action	controller : issued alert controller : issued new clearance
Consequence	faa : investigated
Miss Distance	horizontal : 24000 vertical : 300
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was working R-27 (area B) with moderate traffic. I had an aircraft #1 from pmd-mry at FL260. An air carrier Y checked on climbing to FL230. I had climbed to air carrier Y to FL310 to get above aircraft #1. I made a call to another aircraft then checked back on the air carrier Y and aircraft #1. I expedited the air carrier Y through FL270 to maintain FL310. Air carrier Y said he was doing 2000 FPM if that was enough. With that climb rate and distance from aircraft #1, it was sufficient to get above. When I realized it was not going to work I turned air carrier Y 30 degrees right to turn behind the aircraft #1 and keep separation. At that time it was too late. I asked for a report out of FL270 and separation was lost.

Original NASA ASRS Text

Title: ZLA CTLR EXPERIENCED OPERROR AT FL260 WHEN CLBING ACFT ABOVE CRUISE ACFT.

Narrative: I WAS WORKING R-27 (AREA B) WITH MODERATE TFC. I HAD AN ACFT #1 FROM PMD-MRY AT FL260. AN ACR Y CHKED ON CLBING TO FL230. I HAD CLBED TO ACR Y TO FL310 TO GET ABOVE ACFT #1. I MADE A CALL TO ANOTHER ACFT THEN CHKED BACK ON THE ACR Y AND ACFT #1. I EXPEDITED THE ACR Y THROUGH FL270 TO MAINTAIN FL310. ACR Y SAID HE WAS DOING 2000 FPM IF THAT WAS ENOUGH. WITH THAT CLB RATE AND DISTANCE FROM ACFT #1, IT WAS SUFFICIENT TO GET ABOVE. WHEN I REALIZED IT WAS NOT GOING TO WORK I TURNED ACR Y 30 DEGS R TO TURN BEHIND THE ACFT #1 AND KEEP SEPARATION. AT THAT TIME IT WAS TOO LATE. I ASKED FOR A RPT OUT OF FL270 AND SEPARATION 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.