Narrative:

I was the manual controller at the sector and communicated with mie tower via landlines to pass flight plans and issue departure clrncs. Mie tower requested departure and was given a release on course, climb to 5000 ft. Departure was from runway 32 with on course direct shb (210 degrees approximately). A return call and release was given to aircraft #2 for 3 min interval, with climb to 3000 ft, on course from runway 32 (on course was a 190 degree turn, direct lou). Aircraft #1 checked on frequency 4 mi southwest climbing from 2000 ft to 5000 ft. Aircraft #2 checked on climbing from 1400 ft to 3000 ft 1 mi southwest of mie. I was in error, misusing the departure rules and 5 mi or 1000 ft as not maintained. A review of 7110.65 reveals 6-2-2, multi departures, same course, same runway allowing 3 min interval provided the second aircraft climbs above the first. I did not include the altitude restr. However, it appeared aircraft #1 flew a more extended runway heading prior to his turn than aircraft #2 who turned immediately off the end of the runway. This shorter course possibly compromised my effort to create 5 mi or more. A question then comes to mind, 6-2-2 doesn't seem to dictate same course any further than just that. Common sense for me says that with these large on-course turns, occurring at different times or rates, puts safety at risk. Same course being runway heading or minimal turn appears to be more appropriate. Secondly, in 6-2-2 how does one ensure 3 min interval until altitude is accomplished? 6-2-2 does not mention speed control or similar type. Similar type/performance is mentioned for divergent courses.

Google
 

Original NASA ASRS Text

Title: ZID CTLR APPLIES INCORRECT MANUAL SEPARATION CRITERIA TO A PA28 FOLLOWED BY A PA32 AND SEPARATION IS LOST ON DEP OFF MIE ARPT.

Narrative: I WAS THE MANUAL CTLR AT THE SECTOR AND COMMUNICATED WITH MIE TWR VIA LANDLINES TO PASS FLT PLANS AND ISSUE DEP CLRNCS. MIE TWR REQUESTED DEP AND WAS GIVEN A RELEASE ON COURSE, CLB TO 5000 FT. DEP WAS FROM RWY 32 WITH ON COURSE DIRECT SHB (210 DEGS APPROX). A RETURN CALL AND RELEASE WAS GIVEN TO ACFT #2 FOR 3 MIN INTERVAL, WITH CLB TO 3000 FT, ON COURSE FROM RWY 32 (ON COURSE WAS A 190 DEG TURN, DIRECT LOU). ACFT #1 CHKED ON FREQ 4 MI SW CLBING FROM 2000 FT TO 5000 FT. ACFT #2 CHKED ON CLBING FROM 1400 FT TO 3000 FT 1 MI SW OF MIE. I WAS IN ERROR, MISUSING THE DEP RULES AND 5 MI OR 1000 FT AS NOT MAINTAINED. A REVIEW OF 7110.65 REVEALS 6-2-2, MULTI DEPS, SAME COURSE, SAME RWY ALLOWING 3 MIN INTERVAL PROVIDED THE SECOND ACFT CLBS ABOVE THE FIRST. I DID NOT INCLUDE THE ALT RESTR. HOWEVER, IT APPEARED ACFT #1 FLEW A MORE EXTENDED RWY HDG PRIOR TO HIS TURN THAN ACFT #2 WHO TURNED IMMEDIATELY OFF THE END OF THE RWY. THIS SHORTER COURSE POSSIBLY COMPROMISED MY EFFORT TO CREATE 5 MI OR MORE. A QUESTION THEN COMES TO MIND, 6-2-2 DOESN'T SEEM TO DICTATE SAME COURSE ANY FURTHER THAN JUST THAT. COMMON SENSE FOR ME SAYS THAT WITH THESE LARGE ON-COURSE TURNS, OCCURRING AT DIFFERENT TIMES OR RATES, PUTS SAFETY AT RISK. SAME COURSE BEING RWY HDG OR MINIMAL TURN APPEARS TO BE MORE APPROPRIATE. SECONDLY, IN 6-2-2 HOW DOES ONE ENSURE 3 MIN INTERVAL UNTIL ALT IS ACCOMPLISHED? 6-2-2 DOES NOT MENTION SPD CTL OR SIMILAR TYPE. SIMILAR TYPE/PERFORMANCE IS MENTIONED FOR DIVERGENT COURSES.

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.