Small transport X had less than standard separation from air carrier Y. System error.

Attributes
ACN	146083
Time
Date	199005
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : scy
State Reference	TX
Altitude	msl bound lower : 7000 msl bound upper : 7000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw tower : cvg
Operator	general aviation : personal
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller military : 6 controller radar : 3
ASRS Report	146083
Person 2
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation non adherence : clearance
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	controller : issued new clearance other
Consequence	faa : investigated
Miss Distance	horizontal : 27600 vertical : 700
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

C/a activated. Immediate control instructions issued to both aircraft. It appeared one aircraft did not comply. Transmission was made for air carrier Y in question to 'disregard.' 'disregard' was a separate transmission that did not cancel the immediate control inspection. Callback conversation with reporter revealed the following: the reporter stated small transport X was at 8000' headon to air carrier Y light transport at 7000'. Small transport X had to be descended to get below a holding pattern in another area of the reporter's sector. He told the small transport X to expedite descent to 6000'. He was distracted separating aircraft in the holding pattern when the C/a activated between small transport X and air carrier Y. He issued an immediate turn 30 degrees right to both aircraft. It appeared that air carrier Y did not comply so he made a call to air carrier Y, thought he would have separation, and told air carrier Y to disregard. 7 seconds went by from the time air carrier Y was told to turn and the reporter made the next call. Separation was lost between air carrier Y and small transport X. System error was filed.

Original NASA ASRS Text

Title: SMT X HAD LESS THAN STANDARD SEPARATION FROM ACR Y. SYSTEM ERROR.

Narrative: C/A ACTIVATED. IMMEDIATE CTL INSTRUCTIONS ISSUED TO BOTH ACFT. IT APPEARED ONE ACFT DID NOT COMPLY. XMISSION WAS MADE FOR ACR Y IN QUESTION TO 'DISREGARD.' 'DISREGARD' WAS A SEPARATE XMISSION THAT DID NOT CANCEL THE IMMEDIATE CONTROL INSPECTION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: THE RPTR STATED SMT X WAS AT 8000' HEADON TO ACR Y LTT AT 7000'. SMT X HAD TO BE DSNDED TO GET BELOW A HOLDING PATTERN IN ANOTHER AREA OF THE REPORTER'S SECTOR. HE TOLD THE SMT X TO EXPEDITE DESCENT TO 6000'. HE WAS DISTRACTED SEPARATING ACFT IN THE HOLDING PATTERN WHEN THE C/A ACTIVATED BTWN SMT X AND ACR Y. HE ISSUED AN IMMEDIATE TURN 30 DEGS RIGHT TO BOTH ACFT. IT APPEARED THAT ACR Y DID NOT COMPLY SO HE MADE A CALL TO ACR Y, THOUGHT HE WOULD HAVE SEPARATION, AND TOLD ACR Y TO DISREGARD. 7 SECS WENT BY FROM THE TIME ACR Y WAS TOLD TO TURN AND THE RPTR MADE THE NEXT CALL. SEPARATION WAS LOST BTWN ACR Y AND SMT X. SYSTEM ERROR WAS FILED.

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.