ZDV controller lost separation with 2 climbing aircraft.

Attributes
ACN	573989
Time
Date	200302
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : gjt.airport
State Reference	CO
Altitude	msl single value : 15000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv.artcc tower : sle.tower
Operator	general aviation : personal
Make Model Name	Challenger CL600
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Route In Use	departure sid : n/s
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air taxi
Make Model Name	Beech 1900
Operating Under FAR Part	Part 135
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller time certified in position1 : 15
ASRS Report	573989
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera
Resolutory Action	controller : issued alert
Consequence	faa : investigated
Miss Distance	horizontal : 21000
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Aircraft X cleared from ril to sjc, climbed to 16000 ft, called ZDV leaving 90 ft. 4 mins later, aircraft Y gjt to ril checked on climbing to 14000 ft. Radar controller climbed aircraft Y to 15000 ft. I told radar controller aircraft Y was a factor. Aircraft X never called ZDV until aircraft was level at 16000 ft.

Original NASA ASRS Text

Title: ZDV CTLR LOST SEPARATION WITH 2 CLBING ACFT.

Narrative: ACFT X CLRED FROM RIL TO SJC, CLBED TO 16000 FT, CALLED ZDV LEAVING 90 FT. 4 MINS LATER, ACFT Y GJT TO RIL CHKED ON CLBING TO 14000 FT. RADAR CTLR CLBED ACFT Y TO 15000 FT. I TOLD RADAR CTLR ACFT Y WAS A FACTOR. ACFT X NEVER CALLED ZDV UNTIL ACFT WAS LEVEL AT 16000 FT.

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.