Air carrier X had less than standard separation from small aircraft Y. System error.

Attributes
ACN	182561
Time
Date	199107
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : esc
State Reference	MI
Altitude	agl bound lower : 0 agl bound upper : 3000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zmp
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	climbout : initial
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 11
ASRS Report	182561
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Miss Distance	horizontal : 6000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier X called. Frequency congested. Asked for the aircraft at rhi to go ahead. Air carrier X came on frequency, asked for clearance to grb. Got flight progress gave clearance rhi to grb runway 090 climb to 50 report off. Do not remember if air carrier X read back rhi direct grb or esc direct grb or just cleared to grb 50. Do not remember if I acknowledged readback. Do not think I did. Sent inbound traffic into rhi to allow for departure of air carrier X. Air carrier X called off. No radar target at rhi. Target appeared at esc. Idented him. Reclred air carrier X from present position to grb climb to 100. Approximately 1 min and 12 seconds later small aircraft on ILS 9 at esc called on ground esc. Listening to 11 frequencys and lots of chatter. No excuses, but this was a listening error on my part and also air carrier X. I said rhi direct grb. I don't know if he said esc direct grb. I suspect he must have at some point. I didn't get it. He didn't get rhi direct grb on the clearance delivery. This is a problem with aircraft that shuttle back and forth from airport to airport and we have air carrier X going from both places. The small aircraft had to be on final when air carrier X left. However, air carrier X called airborne out of 2300. I don't know exactly when he departed. Possibly there was separation but most likely not. Single frequency sector here would have helped, also, there was very poor radio discipline by the pilots lately. 2-3 clrncs required to get message through to air carrier X.

Original NASA ASRS Text

Title: ACR X HAD LTSS FROM SMA Y. SYS ERROR.

Narrative: ACR X CALLED. FREQ CONGESTED. ASKED FOR THE ACFT AT RHI TO GO AHEAD. ACR X CAME ON FREQ, ASKED FOR CLRNC TO GRB. GOT FLT PROGRESS GAVE CLRNC RHI TO GRB RWY 090 CLB TO 50 RPT OFF. DO NOT REMEMBER IF ACR X READ BACK RHI DIRECT GRB OR ESC DIRECT GRB OR JUST CLRED TO GRB 50. DO NOT REMEMBER IF I ACKNOWLEDGED READBACK. DO NOT THINK I DID. SENT INBOUND TFC INTO RHI TO ALLOW FOR DEP OF ACR X. ACR X CALLED OFF. NO RADAR TARGET AT RHI. TARGET APPEARED AT ESC. IDENTED HIM. RECLRED ACR X FROM PRESENT POS TO GRB CLB TO 100. APPROX 1 MIN AND 12 SECONDS LATER SMA ON ILS 9 AT ESC CALLED ON GND ESC. LISTENING TO 11 FREQS AND LOTS OF CHATTER. NO EXCUSES, BUT THIS WAS A LISTENING ERROR ON MY PART AND ALSO ACR X. I SAID RHI DIRECT GRB. I DON'T KNOW IF HE SAID ESC DIRECT GRB. I SUSPECT HE MUST HAVE AT SOME POINT. I DIDN'T GET IT. HE DIDN'T GET RHI DIRECT GRB ON THE CLRNC DELIVERY. THIS IS A PROBLEM WITH ACFT THAT SHUTTLE BACK AND FORTH FROM ARPT TO ARPT AND WE HAVE ACR X GOING FROM BOTH PLACES. THE SMA HAD TO BE ON FINAL WHEN ACR X LEFT. HOWEVER, ACR X CALLED AIRBORNE OUT OF 2300. I DON'T KNOW EXACTLY WHEN HE DEPARTED. POSSIBLY THERE WAS SEPARATION BUT MOST LIKELY NOT. SINGLE FREQ SECTOR HERE WOULD HAVE HELPED, ALSO, THERE WAS VERY POOR RADIO DISCIPLINE BY THE PLTS LATELY. 2-3 CLRNCS REQUIRED TO GET MESSAGE THROUGH TO ACR X.

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.