Medium large transport gets TCASII TA then RA, responds.

Attributes
ACN	273814
Time
Date	199406
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : stl
State Reference	MO
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute airway : zkc
Flight Plan	IFR
Aircraft 2
Operator	other
Make Model Name	Gates Learjet Corp Undifferentiated or Other Model
Operating Under FAR Part	other : other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 15000 flight time type : 350
ASRS Report	273814
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe conflict : airborne less severe non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : took evasive action flight crew : returned to intended course or assigned course
Consequence	Other
Miss Distance	horizontal : 0 vertical : 900
Supplementary
Primary Problem	Navigational Facility
Air Traffic Incident	Operational Error other

Narrative:

I was the PF. ZKC center relayed a substantial route change from ZFW for WX. We made our large heading change over stl VOR and a frequency change. The new frequency (127.22) was blocked by an open microphone and at that moment we got a TCASII TA. As we changed scales on the map display to analyze the situation, we got an RA. I followed the RA guidance that also kept us from conflicting with another opposite direction aircraft at FL330. After the 'clear of traffic' we returned to FL310. ATC later advised the RA was caused by a C21 (non-TCASII) at FL310. Our check-on and ATC attempts to avoid the conflict were blocked by the open microphone. Additionally, I saw the traffic at FL330 (could have cleared that visually) but the captain saw the C-21 only as it passed below us. This seemed to be a textbook TA with the TCASII stopping a disaster in the making.

Original NASA ASRS Text

Title: MLG GETS TCASII TA THEN RA, RESPONDS.

Narrative: I WAS THE PF. ZKC CTR RELAYED A SUBSTANTIAL RTE CHANGE FROM ZFW FOR WX. WE MADE OUR LARGE HDG CHANGE OVER STL VOR AND A FREQ CHANGE. THE NEW FREQ (127.22) WAS BLOCKED BY AN OPEN MIKE AND AT THAT MOMENT WE GOT A TCASII TA. AS WE CHANGED SCALES ON THE MAP DISPLAY TO ANALYZE THE SIT, WE GOT AN RA. I FOLLOWED THE RA GUIDANCE THAT ALSO KEPT US FROM CONFLICTING WITH ANOTHER OPPOSITE DIRECTION ACFT AT FL330. AFTER THE 'CLR OF TFC' WE RETURNED TO FL310. ATC LATER ADVISED THE RA WAS CAUSED BY A C21 (NON-TCASII) AT FL310. OUR CHK-ON AND ATC ATTEMPTS TO AVOID THE CONFLICT WERE BLOCKED BY THE OPEN MIKE. ADDITIONALLY, I SAW THE TFC AT FL330 (COULD HAVE CLRED THAT VISUALLY) BUT THE CAPT SAW THE C-21 ONLY AS IT PASSED BELOW US. THIS SEEMED TO BE A TEXTBOOK TA WITH THE TCASII STOPPING A DISASTER IN THE MAKING.

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.