Medium large transport flight crew has TCASII RA. Responds with climb.

Attributes
ACN	203976
Time
Date	199203
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : okk
State Reference	IN
Altitude	msl bound lower : 24000 msl bound upper : 24400
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 15000 flight time type : 2400
ASRS Report	203976
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 0 vertical : 1000
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

Approximately 50 south of okk en route bna ord on radar vectors, received a TA on TCASII. Noted traffic at 12 O'clock climbing out of FL220 (we were at FL240). The intruder aircraft apparently overshot his leveloff at FL230 because we received an RA to 'climb.' we commended a climb and noted intruder was at 23100. At 24400 we received a 'clear of traffic.' we advised ATC of our climb and was told that our traffic was at his assigned altitude of 230. We then descended back to FL240. ATC had not informed us of the traffic so we were not aware of his cleared altitude. When we saw he was at 23100 and because we received an RA we commenced climb not knowing at that time if the intruder was going to level off. As it turns out there was no real conflict. However, the TCASII did its job because it noted the intruder overshot his level off and ordered us to climb.

Original NASA ASRS Text

Title: MLG FLC HAS TCASII RA. RESPONDS WITH CLB.

Narrative: APPROX 50 S OF OKK ENRTE BNA ORD ON RADAR VECTORS, RECEIVED A TA ON TCASII. NOTED TFC AT 12 O'CLOCK CLBING OUT OF FL220 (WE WERE AT FL240). THE INTRUDER ACFT APPARENTLY OVERSHOT HIS LEVELOFF AT FL230 BECAUSE WE RECEIVED AN RA TO 'CLB.' WE COMMENDED A CLB AND NOTED INTRUDER WAS AT 23100. AT 24400 WE RECEIVED A 'CLR OF TFC.' WE ADVISED ATC OF OUR CLB AND WAS TOLD THAT OUR TFC WAS AT HIS ASSIGNED ALT OF 230. WE THEN DSNDED BACK TO FL240. ATC HAD NOT INFORMED US OF THE TFC SO WE WERE NOT AWARE OF HIS CLRED ALT. WHEN WE SAW HE WAS AT 23100 AND BECAUSE WE RECEIVED AN RA WE COMMENCED CLB NOT KNOWING AT THAT TIME IF THE INTRUDER WAS GOING TO LEVEL OFF. AS IT TURNS OUT THERE WAS NO REAL CONFLICT. HOWEVER, THE TCASII DID ITS JOB BECAUSE IT NOTED THE INTRUDER OVERSHOT HIS LEVEL OFF AND ORDERED US TO CLB.

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.