Narrative:

Our aircraft (DC9) departed runway 21R dtw, cleared via the geneva 2 departure at dtw. We were cleared for takeoff runway 21R to fly 200 degree heading and climb to 10000 ft. Jets are to cross the dxo 10 DME arc at or above 5000 ft MSL after takeoff and after cleaning up the aircraft, we climbed at vzf to meet the climb restrs. Prior to our departure an A320 took off ahead of us and assigned a heading of 185 degrees. What happened, the A320 did not make the turn to 185 degrees, but remained runway heading, and we were climbing out of 3000 ft MSL and climb rate was 3500 FPM. Dtw tower told us to level off at 3000 ft. Well, we had passed through 3500 ft already. By the time I stopped the climb, we were at 3700 ft MSL. I had the first officer question the tower, but there was no response, so I started descending to 3000 ft. By this time we were told to contact departure control, told to climb 10000 ft and continue the flight without further incident. When we landed at cmh, I called dtw TRACON to find out what happened. I was told tower thought there was going to be a conflict with the A320 that departed ahead of us. That's why they gave us that clearance. I advised them that we can't stop a climb when passing 3000 ft MSL when we are climbing at 3500 FPM, and that a better clearance would have been to level off at 4000 ft. They agreed. What triggered this was the A320 not turning to 185 degree heading and our high rate of climb and an apparent loss of separation. There was never any TCASII factors to this incident.

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Original NASA ASRS Text

Title: DC9 DEPARTING DTW OVERSHOOTS ATC ASSIGNED ALT.

Narrative: OUR ACFT (DC9) DEPARTED RWY 21R DTW, CLRED VIA THE GENEVA 2 DEP AT DTW. WE WERE CLRED FOR TKOF RWY 21R TO FLY 200 DEG HDG AND CLB TO 10000 FT. JETS ARE TO CROSS THE DXO 10 DME ARC AT OR ABOVE 5000 FT MSL AFTER TKOF AND AFTER CLEANING UP THE ACFT, WE CLBED AT VZF TO MEET THE CLB RESTRS. PRIOR TO OUR DEP AN A320 TOOK OFF AHEAD OF US AND ASSIGNED A HDG OF 185 DEGS. WHAT HAPPENED, THE A320 DID NOT MAKE THE TURN TO 185 DEGS, BUT REMAINED RWY HDG, AND WE WERE CLBING OUT OF 3000 FT MSL AND CLB RATE WAS 3500 FPM. DTW TWR TOLD US TO LEVEL OFF AT 3000 FT. WELL, WE HAD PASSED THROUGH 3500 FT ALREADY. BY THE TIME I STOPPED THE CLB, WE WERE AT 3700 FT MSL. I HAD THE FO QUESTION THE TWR, BUT THERE WAS NO RESPONSE, SO I STARTED DSNDING TO 3000 FT. BY THIS TIME WE WERE TOLD TO CONTACT DEP CTL, TOLD TO CLB 10000 FT AND CONTINUE THE FLT WITHOUT FURTHER INCIDENT. WHEN WE LANDED AT CMH, I CALLED DTW TRACON TO FIND OUT WHAT HAPPENED. I WAS TOLD TWR THOUGHT THERE WAS GOING TO BE A CONFLICT WITH THE A320 THAT DEPARTED AHEAD OF US. THAT'S WHY THEY GAVE US THAT CLRNC. I ADVISED THEM THAT WE CAN'T STOP A CLB WHEN PASSING 3000 FT MSL WHEN WE ARE CLBING AT 3500 FPM, AND THAT A BETTER CLRNC WOULD HAVE BEEN TO LEVEL OFF AT 4000 FT. THEY AGREED. WHAT TRIGGERED THIS WAS THE A320 NOT TURNING TO 185 DEG HDG AND OUR HIGH RATE OF CLB AND AN APPARENT LOSS OF SEPARATION. THERE WAS NEVER ANY TCASII FACTORS TO THIS INCIDENT.

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