Narrative:

Situation: an arrival rush at dtw using runways 3. Downwind traffic descended to 7000' by feeder position and handed off to final east arrival. The east arrival controller is also working the northwest fix and taking handoffs from ZOB. Traffic inbound to det (which is northeast of dtw) from the northwest fix is vectored 3-5 mi south of dtw at 6000', turned eastbound, pointed out to arrival east and handed off to a departure controller over the dtw locs. I was working east arrival. I descended a downwind air carrier from 7000 to 3000'. I forgot about the pointout at 6000'. 30 seconds after issuing the descent I realized the conflict, issued traffic and turned the air carrier to miss the traffic eastbound at 6000', a cga. The air carrier passed behind cga at approximately the same altitude. I accept responsibility for this mistake. However, this procedure is inherently unsafe and contributed to the problem. This procedure (called the 'md route') is recognized as being dangerous and has been eliminated from new airspace being implemented in this fall 1989. There have been numerous attempts by controllers at dtw to change the procedure by moving it or changing the altitude, but management has resisted. There have been numerous close calls (documented and otherwise) involving the 'md,' but no change has been allowed. Management has insisted this route be run at 6000' and has removed controller discretion to use alternate altitudes or routing.

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Original NASA ASRS Text

Title: ACR WAS DESCENDED TO AN ALT OCCUPIED BY ANOTHER ACFT.

Narrative: SITUATION: AN ARR RUSH AT DTW USING RWYS 3. DOWNWIND TFC DSNDED TO 7000' BY FEEDER POS AND HANDED OFF TO FINAL E ARR. THE E ARR CTLR IS ALSO WORKING THE NW FIX AND TAKING HDOFS FROM ZOB. TFC INBND TO DET (WHICH IS NE OF DTW) FROM THE NW FIX IS VECTORED 3-5 MI S OF DTW AT 6000', TURNED EBND, POINTED OUT TO ARR E AND HANDED OFF TO A DEP CTLR OVER THE DTW LOCS. I WAS WORKING E ARR. I DSNDED A DOWNWIND ACR FROM 7000 TO 3000'. I FORGOT ABOUT THE POINTOUT AT 6000'. 30 SECS AFTER ISSUING THE DSCNT I REALIZED THE CONFLICT, ISSUED TFC AND TURNED THE ACR TO MISS THE TFC EBND AT 6000', A CGA. THE ACR PASSED BEHIND CGA AT APPROX THE SAME ALT. I ACCEPT RESPONSIBILITY FOR THIS MISTAKE. HOWEVER, THIS PROC IS INHERENTLY UNSAFE AND CONTRIBUTED TO THE PROB. THIS PROC (CALLED THE 'MD ROUTE') IS RECOGNIZED AS BEING DANGEROUS AND HAS BEEN ELIMINATED FROM NEW AIRSPACE BEING IMPLEMENTED IN THIS FALL 1989. THERE HAVE BEEN NUMEROUS ATTEMPTS BY CTLRS AT DTW TO CHANGE THE PROC BY MOVING IT OR CHANGING THE ALT, BUT MGMNT HAS RESISTED. THERE HAVE BEEN NUMEROUS CLOSE CALLS (DOCUMENTED AND OTHERWISE) INVOLVING THE 'MD,' BUT NO CHANGE HAS BEEN ALLOWED. MGMNT HAS INSISTED THIS ROUTE BE RUN AT 6000' AND HAS REMOVED CTLR DISCRETION TO USE ALTERNATE ALTS OR ROUTING.

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.