ZKC controller experienced TCASII RA event resulting in loss of separation.

Attributes
ACN	594337
Time
Date	200309
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : cap.vortac
State Reference	IL
Altitude	msl single value : 29000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc.artcc tower : las.tower
Operator	common carrier : air carrier
Make Model Name	BAe 146 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zkc.artcc
Operator	common carrier : air carrier
Make Model Name	B717 (Formerly MD-95)
Operating Under FAR Part	Part 121
Flight Phase	cruise : enroute altitude change
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller military : 4 controller non radar : 1 controller radar : 18 controller time certified in position1 : 12 controller time certified in position2 : 8
ASRS Report	594337
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : required legal separation
Independent Detector	atc equipment : conflict alert aircraft equipment : tcas other controllera
Resolutory Action	controller : issued advisory controller : issued new clearance flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 8000 vertical : 400
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

Sector exceeded established saturation parameters at the time of the incident, however, that was not a causal factor, it merely precluded the issuance of TA or non-merging targets. A BA46 air carrier at FL270 experienced a TCASII monitor error to reduce rate of climb while the aircraft was in level flight, which caused the B712 to get a TCASII alert and climb from FL280 to FL290. The B712 pilot advised ATC that he was in a TCASII climb. ATC advised the B712 pilot to maintain his altitude and issued converging traffic (A319 at FL290), and the BA46 traffic at FL220. The B712 pilot advised he was leaving FL290 for FL280. ATC issued an immediate 90 degree right turn to the A319, who in turn advised that he had the B712 traffic in sight and was responding to a TCASII alert. ATC advised the A319 to return to FL290 as soon as possible.

Original NASA ASRS Text

Title: ZKC CTLR EXPERIENCED TCASII RA EVENT RESULTING IN LOSS OF SEPARATION.

Narrative: SECTOR EXCEEDED ESTABLISHED SATURATION PARAMETERS AT THE TIME OF THE INCIDENT, HOWEVER, THAT WAS NOT A CAUSAL FACTOR, IT MERELY PRECLUDED THE ISSUANCE OF TA OR NON-MERGING TARGETS. A BA46 AIR CARRIER AT FL270 EXPERIENCED A TCASII MONITOR ERROR TO REDUCE RATE OF CLB WHILE THE ACFT WAS IN LEVEL FLT, WHICH CAUSED THE B712 TO GET A TCASII ALERT AND CLB FROM FL280 TO FL290. THE B712 PLT ADVISED ATC THAT HE WAS IN A TCASII CLB. ATC ADVISED THE B712 PLT TO MAINTAIN HIS ALT AND ISSUED CONVERGING TFC (A319 AT FL290), AND THE BA46 TFC AT FL220. THE B712 PLT ADVISED HE WAS LEAVING FL290 FOR FL280. ATC ISSUED AN IMMEDIATE 90 DEG R TURN TO THE A319, WHO IN TURN ADVISED THAT HE HAD THE B712 TFC IN SIGHT AND WAS RESPONDING TO A TCASII ALERT. ATC ADVISED THE A319 TO RETURN TO FL290 AS SOON AS POSSIBLE.

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.