B727 had a TCASII RA with a descending A320.

Attributes
ACN	464970
Time
Date	200002
Day	Sat
Local Time Of Day	1201 To 1800
Place
State Reference	KS
Altitude	msl bound lower : 26000 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc.artcc
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zkc.artcc
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time last 90 days : 120 flight time total : 18000 flight time type : 7000
ASRS Report	464970
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	conflict : airborne less severe
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	flight crew : took evasive action
Miss Distance	horizontal : 6000 vertical : 1000
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

After passing colorado springs, ride deteriorated at 33000 ft and descent was made to FL270 and smooth air. At point referenced above TCASII commanded 'descend now.' descended to FL260 and observed on TCASII and visually, A320 descending to FL280 (confirmed later). Advised center of deviation, returned to FL270 and continued. I believe the proximity, closure rate and descent rate of A320 may have been greater than the computing time for the TCASII.

Original NASA ASRS Text

Title: B727 HAD A TCASII RA WITH A DSNDING A320.

Narrative: AFTER PASSING COLORADO SPRINGS, RIDE DETERIORATED AT 33000 FT AND DSCNT WAS MADE TO FL270 AND SMOOTH AIR. AT POINT REFED ABOVE TCASII COMMANDED 'DSND NOW.' DSNDED TO FL260 AND OBSERVED ON TCASII AND VISUALLY, A320 DSNDING TO FL280 (CONFIRMED LATER). ADVISED CTR OF DEV, RETURNED TO FL270 AND CONTINUED. I BELIEVE THE PROX, CLOSURE RATE AND DSCNT RATE OF A320 MAY HAVE BEEN GREATER THAN THE COMPUTING TIME FOR THE TCASII.

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.