D21 controller described a loss of legal heavy separation on final for runway 4L when all the techni...

Attributes
ACN	884630
Time
Date	201004
Local Time Of Day	1201-1800
Place
Locale Reference	DTW.Airport
State Reference	MI
Aircraft 1
Make Model Name	Widebody Low Wing 4 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	Visual Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Approach
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance

Narrative:

I was vectoring for visual approaches to runway 4 left at dtw. Air carrier X was cleared for a visual approach to 4 left and air carrier Y was next for the approach. Air carrier Y reported air carrier X in sight and I told air carrier Y to plan to follow and turned to a base heading. I realized that air carrier Y might pass less than 5 miles behind and I told air carrier Y to maintain visual separation from that traffic and the pilot responded 'roger'. Because the pilot did not use its call sign no visual separation could be used. Air carrier Y was turned in shortly after and followed air carrier X on a visual approach. Recommendation; air carrier Y had previously called air carrier X in sight and I should have said maintain visual separation instead of plan to follow especially with wake turbulence involved. Lesson learned.

Original NASA ASRS Text

Title: D21 Controller described a loss of legal heavy separation on final for Runway 4L when all the technicalities and phraseology's for visual separation were not completed.

Narrative: I was vectoring for visual approaches to Runway 4 left at DTW. Air Carrier X was cleared for a visual approach to 4 left and Air Carrier Y was next for the approach. Air Carrier Y reported Air Carrier X in sight and I told Air Carrier Y to plan to follow and turned to a base heading. I realized that Air Carrier Y might pass less than 5 miles behind and I told Air Carrier Y to maintain visual separation from that traffic and the pilot responded 'Roger'. Because the pilot did not use its call sign no visual separation could be used. Air Carrier Y was turned in shortly after and followed Air Carrier X on a visual approach. Recommendation; Air Carrier Y had previously called Air Carrier X in sight and I should have said maintain visual separation instead of plan to follow especially with wake turbulence involved. Lesson learned.

Data retrieved from NASA's ASRS site as of April 2012 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.

D21 controller described a loss of legal heavy separation on final for runway 4L when all the technicalities and phraseology's for visual separation were not completed.