Air carrier was sequenced 2 miles behind another air carrier resulting in less than standard separat...

Attributes
ACN	127945
Time
Date	198910
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : den
State Reference	CO
Altitude	msl bound lower : 8000 msl bound upper : 9000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : den
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	descent : approach descent other
Route In Use	arrival other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent : approach descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller radar : 23
ASRS Report	127945
Person 2
Affiliation	government : faa
Function	oversight : coordinator
Qualification	controller : radar
Events
Anomaly	non adherence : required legal separation non adherence : published procedure other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Miss Distance	horizontal : 12000 vertical : 600
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Intra Facility Coordination Failure

Narrative:

Air carrier Y was placed 2 mi in trail of air carrier X on the ILS runway 26L final approach. The ci controller was advised and no action was taken to take aircraft off the final. Callback conversation with reporter revealed the following: the reporter said that the incident occurred on a 12 mi final between 8000' and 9000' within the den TCA. Positions were not combined. The second aircraft was an medium large transport about the same airspeed as the first aircraft. The ci controller took the handoff on the second aircraft with less than 3 mi between them. When she mentioned the separation problem, nothing was done about it. The reporter has 23 yrs as an fpl. No error or pilot deviation was filed.

Original NASA ASRS Text

Title: ACR WAS SEQUENCED 2 MILES BEHIND ANOTHER ACR RESULTING IN LESS THAN STANDARD SEPARATION.

Narrative: ACR Y WAS PLACED 2 MI IN TRAIL OF ACR X ON THE ILS RWY 26L FINAL APCH. THE CI CTLR WAS ADVISED AND NO ACTION WAS TAKEN TO TAKE ACFT OFF THE FINAL. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: THE REPORTER SAID THAT THE INCIDENT OCCURRED ON A 12 MI FINAL BETWEEN 8000' AND 9000' WITHIN THE DEN TCA. POSITIONS WERE NOT COMBINED. THE SECOND ACFT WAS AN MLG ABOUT THE SAME AIRSPEED AS THE FIRST ACFT. THE CI CTLR TOOK THE HANDOFF ON THE SECOND ACFT WITH LESS THAN 3 MI BETWEEN THEM. WHEN SHE MENTIONED THE SEPARATION PROBLEM, NOTHING WAS DONE ABOUT IT. THE REPORTER HAS 23 YRS AS AN FPL. NO ERROR OR PLT DEVIATION WAS FILED.

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

Air carrier was sequenced 2 miles behind another air carrier resulting in less than standard separation.