Widebody transport receives TCASII RA. Responds.

Attributes
ACN	224532
Time
Date	199210
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lax
State Reference	CA
Altitude	msl bound lower : 23200 msl bound upper : 24000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 15000 flight time type : 3000
ASRS Report	224532
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Widebody transport lax to stl on radar vector heading 070 degree in stop climb, maintaining FL240 assigned. When we received a TCASII RA at FL240, I advised ZLA widebody transport was leaving FL240 due to a TCASII warning. ZLA advised us that the other aircraft was at FL250. We descended to FL23.2 then received a 'clear of conflict.' at that time the other aircraft indicated 1/2 mi behind and at plus 18. It appears that the rate of descent of the other aircraft from FL260 to FL250 caused the RA.

Original NASA ASRS Text

Title: WDB RECEIVES TCASII RA. RESPONDS.

Narrative: WDB LAX TO STL ON RADAR VECTOR HDG 070 DEG IN STOP CLB, MAINTAINING FL240 ASSIGNED. WHEN WE RECEIVED A TCASII RA AT FL240, I ADVISED ZLA WDB WAS LEAVING FL240 DUE TO A TCASII WARNING. ZLA ADVISED US THAT THE OTHER ACFT WAS AT FL250. WE DSNDED TO FL23.2 THEN RECEIVED A 'CLR OF CONFLICT.' AT THAT TIME THE OTHER ACFT INDICATED 1/2 MI BEHIND AND AT PLUS 18. IT APPEARS THAT THE RATE OF DSCNT OF THE OTHER ACFT FROM FL260 TO FL250 CAUSED THE RA.

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.