Narrative:

I was working radar combined in the tower. Local control had launched the DC9 runway heading off runway 27; with no restr. I climbed the DC9 to 10000 ft and started the DC9 in a left turn to the south until he could climb above the 3 aircraft on final and vectors to final to runway 31. I then turned the DC9 further to a 130 degree heading. Local then gave me another departure; the C525 on a 180 heading; climbing to 5000 ft. On contact; it appeared to me that the C525 might not get behind the DC9 and diverge; so I told him to stop his climb at 4000 ft. The citation had a very high rate of climb and had turned extremely tight to 180 degrees. By the time the C525 acknowledged the stop at 4000 ft; he was past it and still climbing and had to descend back. The tight turn put him inside the DC9's track; combined with the DC9's slow rate of climb and turn; put them both in the same airspace at the same time. Causal factors; in my opinion: 1) local had just taken the position. 2) the previous local controller had launched the DC9; the relieving controller launched the C525. 3) I was about to be relieved and was trying to clean up the arrs. 4) unusual influx of inbounds and outbounds; while combined in the tower. 5) a strong north wind aloft. 6) the DC9 would usually go on a northeast heading; but filed for an ese course. 7) the DC9 turned and climbed unusually slow. 8) the citation climbed and turned unusually fast; a normal turn would have had him diverge correctly from the DC9. 9) local was getting the citation out before an arrival on runway 31 (hitting a slot; without the ability to tiph). Prevention: local to take it a bit slower right after taking position. Maybe stick with the fan-headings until the full picture is understood 100%. If we were allowed tiph (taxi into position and hold) the local controller may have had the time to look at the picture closer.

Related reports:

Google
 

Original NASA ASRS Text

Title: CID DEP CTLR EXPERIENCED OPERROR AT 4000 FT WHEN SECOND DEP TURNED INSIDE PREVIOUS DEP AND CLBED TO OCCUPIED ALT.

Narrative: I WAS WORKING RADAR COMBINED IN THE TWR. LCL CTL HAD LAUNCHED THE DC9 RWY HDG OFF RWY 27; WITH NO RESTR. I CLBED THE DC9 TO 10000 FT AND STARTED THE DC9 IN A L TURN TO THE S UNTIL HE COULD CLB ABOVE THE 3 ACFT ON FINAL AND VECTORS TO FINAL TO RWY 31. I THEN TURNED THE DC9 FURTHER TO A 130 DEG HDG. LCL THEN GAVE ME ANOTHER DEP; THE C525 ON A 180 HDG; CLBING TO 5000 FT. ON CONTACT; IT APPEARED TO ME THAT THE C525 MIGHT NOT GET BEHIND THE DC9 AND DIVERGE; SO I TOLD HIM TO STOP HIS CLB AT 4000 FT. THE CITATION HAD A VERY HIGH RATE OF CLB AND HAD TURNED EXTREMELY TIGHT TO 180 DEGS. BY THE TIME THE C525 ACKNOWLEDGED THE STOP AT 4000 FT; HE WAS PAST IT AND STILL CLBING AND HAD TO DSND BACK. THE TIGHT TURN PUT HIM INSIDE THE DC9'S TRACK; COMBINED WITH THE DC9'S SLOW RATE OF CLB AND TURN; PUT THEM BOTH IN THE SAME AIRSPACE AT THE SAME TIME. CAUSAL FACTORS; IN MY OPINION: 1) LCL HAD JUST TAKEN THE POS. 2) THE PREVIOUS LCL CTLR HAD LAUNCHED THE DC9; THE RELIEVING CTLR LAUNCHED THE C525. 3) I WAS ABOUT TO BE RELIEVED AND WAS TRYING TO CLEAN UP THE ARRS. 4) UNUSUAL INFLUX OF INBOUNDS AND OUTBOUNDS; WHILE COMBINED IN THE TWR. 5) A STRONG N WIND ALOFT. 6) THE DC9 WOULD USUALLY GO ON A NE HDG; BUT FILED FOR AN ESE COURSE. 7) THE DC9 TURNED AND CLBED UNUSUALLY SLOW. 8) THE CITATION CLBED AND TURNED UNUSUALLY FAST; A NORMAL TURN WOULD HAVE HAD HIM DIVERGE CORRECTLY FROM THE DC9. 9) LCL WAS GETTING THE CITATION OUT BEFORE AN ARR ON RWY 31 (HITTING A SLOT; WITHOUT THE ABILITY TO TIPH). PREVENTION: LCL TO TAKE IT A BIT SLOWER RIGHT AFTER TAKING POS. MAYBE STICK WITH THE FAN-HEADINGS UNTIL THE FULL PICTURE IS UNDERSTOOD 100%. IF WE WERE ALLOWED TIPH (TAXI INTO POS AND HOLD) THE LCL CTLR MAY HAVE HAD THE TIME TO LOOK AT THE PICTURE CLOSER.

Data retrieved from NASA's ASRS site as of January 2009 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.