Air carrier X TCASII TA RA climb had less than standard separation from aircraft Y. System error.

Attributes
ACN	202099
Time
Date	199202
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : bal
State Reference	MD
Altitude	msl bound lower : 10500 msl bound upper : 10500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bwi artcc : zdv
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude descent other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
ASRS Report	202099
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : undershoot conflict : airborne less severe non adherence : required legal separation non adherence : published procedure non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action none taken : unable
Consequence	Other
Miss Distance	horizontal : 6000 vertical : 400
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Traffic conflict was apparent visually and resolution was initiated by pilot before TCASII RA was given. As a result, the maneuver to avoid conflict was much smoother. ATC never gave TA, although ATC requested (several times) for aircraft Y to increase rate of descent. We informed ATC of our need to climb to avoid conflict which was approved.

Original NASA ASRS Text

Title: ACR X TCASII TA RA CLB HAD LTSS FROM ACFT Y. SYS ERROR.

Narrative: TFC CONFLICT WAS APPARENT VISUALLY AND RESOLUTION WAS INITIATED BY PLT BEFORE TCASII RA WAS GIVEN. AS A RESULT, THE MANEUVER TO AVOID CONFLICT WAS MUCH SMOOTHER. ATC NEVER GAVE TA, ALTHOUGH ATC REQUESTED (SEVERAL TIMES) FOR ACFT Y TO INCREASE RATE OF DSCNT. WE INFORMED ATC OF OUR NEED TO CLB TO AVOID CONFLICT WHICH WAS APPROVED.

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.