Medium large transport receives a TA then RA on TCASII at cruise.

Attributes
ACN	249217
Time
Date	199308
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : uin
State Reference	IL
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc tower : cdg
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent 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 : 100 flight time total : 11000 flight time type : 2500
ASRS Report	249217
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot conflict : airborne less severe non adherence : clearance non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 24000 vertical : 800
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation Operational Error

Narrative:

Noticed intruder aircraft at 12 O'clock and 10 plus mi, 2200 ft above us, descending. We were level at FL310 wbound towards uin VOR as intruder descended through 2000 ft above our altitude. We selected 10 mi range on TCASII. Intruder continued to descend on reciprocal course and a TA was issued, followed by an RA. As I initiated the descent the first officer reported the RA to ATC, who then issued TA. First officer sighted intruder and pointed him out to me. Since it was evident that intruder would pass off to our right, I discontinued descent and leveled at FL310. Total altitude deviation was approximately 100 ft. ATC advised that his conflict alert sounded as we were reporting our RA. A brief discussion between ATC and the other aircraft indicated some confusion between them regarding the clearance that had been assigned to that aircraft. I believe that the other aircraft was going direct to capitol VOR.

Original NASA ASRS Text

Title: MLG RECEIVES A TA THEN RA ON TCASII AT CRUISE.

Narrative: NOTICED INTRUDER ACFT AT 12 O'CLOCK AND 10 PLUS MI, 2200 FT ABOVE US, DSNDING. WE WERE LEVEL AT FL310 WBOUND TOWARDS UIN VOR AS INTRUDER DSNDED THROUGH 2000 FT ABOVE OUR ALT. WE SELECTED 10 MI RANGE ON TCASII. INTRUDER CONTINUED TO DSND ON RECIPROCAL COURSE AND A TA WAS ISSUED, FOLLOWED BY AN RA. AS I INITIATED THE DSCNT THE FO RPTED THE RA TO ATC, WHO THEN ISSUED TA. FO SIGHTED INTRUDER AND POINTED HIM OUT TO ME. SINCE IT WAS EVIDENT THAT INTRUDER WOULD PASS OFF TO OUR R, I DISCONTINUED DSCNT AND LEVELED AT FL310. TOTAL ALTDEV WAS APPROX 100 FT. ATC ADVISED THAT HIS CONFLICT ALERT SOUNDED AS WE WERE RPTING OUR RA. A BRIEF DISCUSSION BTWN ATC AND THE OTHER ACFT INDICATED SOME CONFUSION BTWN THEM REGARDING THE CLRNC THAT HAD BEEN ASSIGNED TO THAT ACFT. I BELIEVE THAT THE OTHER ACFT WAS GOING DIRECT TO CAPITOL VOR.

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.