Less than standard separation between two IFR aircraft. Operational error.

Attributes
ACN	94228
Time
Date	198809
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : svm airport : dtw
State Reference	MI
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other other
Route In Use	enroute airway : v2
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 2
ASRS Report	94228
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : developmental
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance none taken : insufficient time other
Consequence	faa : investigated
Miss Distance	horizontal : 18900 vertical : 200
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was training a developmental radar controller at the time. We were holding aircraft due to WX at dtw. The developmental controller forgot to clear one aircraft over the holding fix after dtw approach accepted the handoff. I was coordinating with the supervisor about the sequence of arrs at the time, and did not catch the developmental controller's mistake. Our next arrival was on vectors to provide 15 mi in trail behind the first aircraft. I saw the first aircraft make a right turn in the pattern instead of proceeding on towards the airport, then I descended the second inbound immediately to avoid the traffic. The corrective action to prevent a recurrent error like this is to concentrate on training primarily and outside distrs secondarily.

Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN TWO IFR ACFT. OPERATIONAL ERROR.

Narrative: I WAS TRAINING A DEVELOPMENTAL RADAR CTLR AT THE TIME. WE WERE HOLDING ACFT DUE TO WX AT DTW. THE DEVELOPMENTAL CTLR FORGOT TO CLR ONE ACFT OVER THE HOLDING FIX AFTER DTW APCH ACCEPTED THE HDOF. I WAS COORDINATING WITH THE SUPVR ABOUT THE SEQUENCE OF ARRS AT THE TIME, AND DID NOT CATCH THE DEVELOPMENTAL CTLR'S MISTAKE. OUR NEXT ARR WAS ON VECTORS TO PROVIDE 15 MI IN TRAIL BEHIND THE FIRST ACFT. I SAW THE FIRST ACFT MAKE A R TURN IN THE PATTERN INSTEAD OF PROCEEDING ON TOWARDS THE ARPT, THEN I DSNDED THE SECOND INBND IMMEDIATELY TO AVOID THE TFC. THE CORRECTIVE ACTION TO PREVENT A RECURRENT ERROR LIKE THIS IS TO CONCENTRATE ON TRAINING PRIMARILY AND OUTSIDE DISTRS SECONDARILY.

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.