Air carrier X TCASII RA slowed descent to assigned altitude. Cltr conception knowledge TCASII.

Attributes
ACN	201800
Time
Date	199202
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ord
State Reference	IL
Altitude	msl bound lower : 6000 msl bound upper : 7000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : intermediate altitude
Route In Use	departure other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
ASRS Report	201800
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	vertical : 1000
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

I was working east arrival air carrier X was issued a clearance to descend and maintain 7000. Traffic Y departed midway climbing east bound to 6000. Air carrier X advised me of receiving a RA to slow descent. The targets never merged and separation exceeded 1000 ft vertically. The parameters for this TCASII RA were not appropriate. Since the targets never merged, and neither aircraft turned, the alert should only have been a TA rather than a RA! These type of TCASII reports and TCASII responses are not only disruptive to the controller but could also create a needless unsafe condition.

Original NASA ASRS Text

Title: ACR X TCASII RA SLOWED DSCNT TO ASSIGNED ALT. CLTR CONCEPTION KNOWLEDGE TCASII.

Narrative: I WAS WORKING E ARR ACR X WAS ISSUED A CLRNC TO DSND AND MAINTAIN 7000. TFC Y DEPARTED MIDWAY CLBING E BOUND TO 6000. ACR X ADVISED ME OF RECEIVING A RA TO SLOW DSCNT. THE TARGETS NEVER MERGED AND SEPARATION EXCEEDED 1000 FT VERTICALLY. THE PARAMETERS FOR THIS TCASII RA WERE NOT APPROPRIATE. SINCE THE TARGETS NEVER MERGED, AND NEITHER ACFT TURNED, THE ALERT SHOULD ONLY HAVE BEEN A TA RATHER THAN A RA! THESE TYPE OF TCASII RPTS AND TCASII RESPONSES ARE NOT ONLY DISRUPTIVE TO THE CTLR BUT COULD ALSO CREATE A NEEDLESS UNSAFE CONDITION.

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.