Trainee approach controller descended an small transport through altitude of enroute mdt. Aircraft initially under separate ATC jurisdiction. Less than standard separation detected by ARTCC oedp and approach controller advised.

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Attributes
ACN	86804
Time
Date	198805
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : eug
State Reference	OR
Altitude	msl bound lower : 9100 msl bound upper : 9800
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : eug
Operator	common carrier : air taxi
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Flight Phase	descent other
Route In Use	enroute : direct enroute airway : zse enroute airway : eug
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air taxi
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
ASRS Report	86804
Person 2
Function	controller : approach
Qualification	controller : developmental
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 700
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was instructing a trnee working the radar flight position. Mdt Y was an overflt at 9000' southbound on V23 about over albany, or. Small transport X was southbound for landing at eug. Altitude was descending from 10400 to 10000' on initial contact. Small transport X was approximately 2 mi east of mdt Y. The radar controller on her first transmission gave small transport X descent to 5000'. She quickly saw a conflict possibility and called the sea center sector for control of mdt Y. She issued a right turn heading 210 degrees to mdt Y, but altitude readout to me showed mdt Y at 9100' and small transport X at 9800'. Shortly a call came to the supervisor's desk which I told my trnee to answer. It was the sea center supervisor with a report that the 2 aircraft were 2 mi apart as shown on their alarm system west/O a thousand ft vertical sep in the clouds. A brief investigation and replay of the taped voice recording followed. The occurrence was dismissed with no further request for data printout from the sea center computer. Planes involved were in clouds and so no visual sighting occurred of each other. Very poor controller judgement in an obvious situation. 1000' and 3 mi sep very doubtful! Prevention: don't do it again.

Original NASA ASRS Text

Title: TRAINEE APCH CTLR DESCENDED AN SMT THROUGH ALT OF ENROUTE MDT. ACFT INITIALLY UNDER SEPARATE ATC JURISDICTION. LESS THAN STANDARD SEPARATION DETECTED BY ARTCC OEDP AND APCH CTLR ADVISED.

Narrative: I WAS INSTRUCTING A TRNEE WORKING THE RADAR FLT POS. MDT Y WAS AN OVERFLT AT 9000' SBND ON V23 ABOUT OVER ALBANY, OR. SMT X WAS SBND FOR LNDG AT EUG. ALT WAS DSNDING FROM 10400 TO 10000' ON INITIAL CONTACT. SMT X WAS APPROX 2 MI E OF MDT Y. THE RADAR CTLR ON HER FIRST XMISSION GAVE SMT X DSCNT TO 5000'. SHE QUICKLY SAW A CONFLICT POSSIBILITY AND CALLED THE SEA CENTER SECTOR FOR CTL OF MDT Y. SHE ISSUED A RIGHT TURN HDG 210 DEGS TO MDT Y, BUT ALT READOUT TO ME SHOWED MDT Y AT 9100' AND SMT X AT 9800'. SHORTLY A CALL CAME TO THE SUPVR'S DESK WHICH I TOLD MY TRNEE TO ANSWER. IT WAS THE SEA CENTER SUPVR WITH A RPT THAT THE 2 ACFT WERE 2 MI APART AS SHOWN ON THEIR ALARM SYS W/O A THOUSAND FT VERT SEP IN THE CLOUDS. A BRIEF INVESTIGATION AND REPLAY OF THE TAPED VOICE RECORDING FOLLOWED. THE OCCURRENCE WAS DISMISSED WITH NO FURTHER REQUEST FOR DATA PRINTOUT FROM THE SEA CENTER COMPUTER. PLANES INVOLVED WERE IN CLOUDS AND SO NO VISUAL SIGHTING OCCURRED OF EACH OTHER. VERY POOR CTLR JUDGEMENT IN AN OBVIOUS SITUATION. 1000' AND 3 MI SEP VERY DOUBTFUL! PREVENTION: DON'T DO IT AGAIN.

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.