Air carrier X had less than standard separation from B-757 on approach. System error.

Attributes
ACN	299689
Time
Date	199503
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : atl
State Reference	GA
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : atl tracon : fsm
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	ATR 72
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller radar : 14
ASRS Report	299689
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	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 21000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Air carrier X was cleared for ILS runway 9R 4.5 mi behind air carrier Y, b- 757. Y reduced speed inside the OM. X closed to 3.5 mi behind Y and was taken off the approach and resequenced. X should not have been turned onto final so close to Y. Supervisors and industry pressure tend to push controllers to use minimum spacing without room for error. With the volume of traffic at atl we constantly 'push the limit' when we should be adding more spacing for safety reasons.

Original NASA ASRS Text

Title: ACR X HAD LTSS FROM B-757 ON APCH. SYS ERROR.

Narrative: ACR X WAS CLRED FOR ILS RWY 9R 4.5 MI BEHIND ACR Y, B- 757. Y REDUCED SPD INSIDE THE OM. X CLOSED TO 3.5 MI BEHIND Y AND WAS TAKEN OFF THE APCH AND RESEQUENCED. X SHOULD NOT HAVE BEEN TURNED ONTO FINAL SO CLOSE TO Y. SUPVRS AND INDUSTRY PRESSURE TEND TO PUSH CTLRS TO USE MINIMUM SPACING WITHOUT ROOM FOR ERROR. WITH THE VOLUME OF TFC AT ATL WE CONSTANTLY 'PUSH THE LIMIT' WHEN WE SHOULD BE ADDING MORE SPACING FOR SAFETY REASONS.

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.