Controller in training descended a MTR too soon and had less than standard separation with an small ...

Attributes
ACN	97372
Time
Date	198811
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : sli airport : sna
State Reference	CA
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sna
Operator	other
Make Model Name	Military Trainer
Flight Phase	descent other
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
ASRS Report	97372
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : developmental
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	none taken : insufficient time
Consequence	Other
Miss Distance	horizontal : 9000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

The small aircraft Y was south of sli VOR nwbnd descending out of 5300, assigned 4000. The MTR X was handed off to me just over the lax localizer southbound descending out of 10500, assigned 8000. On initial contact my student descended the MTR X to 5000 assuming that both aircraft would continue a normal rate of descent. The MTR X descended at approximately 6000 FPM and passed 1.5 mi in front of the small aircraft Y when both were at 5000.

Original NASA ASRS Text

Title: CTLR IN TRAINING DESCENDED A MTR TOO SOON AND HAD LESS THAN STANDARD SEPARATION WITH AN SMA.

Narrative: THE SMA Y WAS SOUTH OF SLI VOR NWBND DSNDING OUT OF 5300, ASSIGNED 4000. THE MTR X WAS HANDED OFF TO ME JUST OVER THE LAX LOC SBND DSNDING OUT OF 10500, ASSIGNED 8000. ON INITIAL CONTACT MY STUDENT DESCENDED THE MTR X TO 5000 ASSUMING THAT BOTH ACFT WOULD CONTINUE A NORMAL RATE OF DSCNT. THE MTR X DESCENDED AT APPROX 6000 FPM AND PASSED 1.5 MI IN FRONT OF THE SMA Y WHEN BOTH WERE AT 5000.

Data retrieved from NASA's ASRS site as of August 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.

Controller in training descended a MTR too soon and had less than standard separation with an small aircraft.