Narrative:

Air carrier X handed off to an incorrect ZFW frequency. We checked in on the frequency and were unaware that the frequency was incorrect. About 5 mins later we queried the controller about the possibility of proceeding direct to irw. After a moment of confusion with blocked xmissions, he calmly handed us off to another ZFW frequency. This controller commanded us to descend immediately to FL330 and informed us of opposite direction traffic at 5 mi, same altitude, closing very fast. I responded immediately by descending rapidly to FL330. The traffic, cpr Y, was sighted visually at about 4 mi away. We passed about 1/2 mi horizontal and 2000 ft vertically below cpr Y. We later learned that cpr Y was not in communication contact with ZFW. It was equipped with TCASII and performed a climb in response to an RA command. Our medium large transport was not TCASII equipped. Supplemental information from acn 241294: cpr Y did not receive a center frequency change, our last believed frequency was ZKC on 132.65. Even though we had flown outside of kansas city's airspace we did not realize that we had lost communications with kansas city due to the fact that we kept hearing other aircraft on the frequency. We were approximately 70-100 mi north of act at FL350 when we received a TCASII TA. We had the TCASII on the 40 mi scale and in the normal position which covers 2700 ft above and below our altitude on this system. There was no target on the TCASII screen until we received the advisory and the TCASII alerted 'traffic, 'traffic.' the target at this time was about 4-6 mi away (this is according to ZFW's radar tapes when we started our climb). We immediately scanned the area for the traffic, did not see anything, and then I went back inside to look at the TCASII again.(at that moment the thought crossed my mind that this was a false alert.) when I looked at the TCASII I saw the target turn from yellow to red and was alerted 'climb, climb' and was presented with a 1500 FPM climb resolution. I immediately disconnected the autoplt and climbed the aircraft at the prescribed 1500 FPM. At about 600 ft above our altitude the TCASII alerted 'monitor vertical speed,' at that time I believe I stopped the climb. Shortly after TCASII alerted 'clear of conflict' and I then descended back to our assigned altitude of FL350. We then tried to call center to find out about the traffic and realized that we were well outside of kansas city airspace, however before we switched frequencys we still heard an aircraft check in with kansas city, we went to the chart and found a high altitude WX frequency contacted them and they gave us a frequency for ZFW who we then contacted. I feel that an increased situational awareness as to center boundaries on our part would have avoided this situation all together, because we would have questioned center about a frequency change far sooner. I also feel that being about 11 hours into our duty day might have played a part in our being lured into a false sense of security regarding communications. Supplemental information from acn 241845: I was working the radar associate position on a sector 100 mi or more east of this occurrence. My involvement is because air carrier X was put on my frequency by mistake by ZHU. The sector I was working was hearing overload and a radar handoff controller was added within 1 min of when I was advised that air carrier X was erroneously switched to my frequency. I did not hear air carrier X check on frequency and became aware that he was on my frequency when he requested direct irw. I advised my r-side to switch air carrier X to dallas hi, the sector in which the error occurred. At that time, neither my r-side nor I was aware that air carrier X was in potential confliction with the cpr Y. Cpr Y was lost on a ZKC frequency.

Google
 

Original NASA ASRS Text

Title: CPR Y LOST COM TCASII TA RA HAD LTSS WITH ACR X. EVASIVE ACTION TAKEN. PLTDEV. SYS ERROR.

Narrative: ACR X HANDED OFF TO AN INCORRECT ZFW FREQ. WE CHKED IN ON THE FREQ AND WERE UNAWARE THAT THE FREQ WAS INCORRECT. ABOUT 5 MINS LATER WE QUERIED THE CTLR ABOUT THE POSSIBILITY OF PROCEEDING DIRECT TO IRW. AFTER A MOMENT OF CONFUSION WITH BLOCKED XMISSIONS, HE CALMLY HANDED US OFF TO ANOTHER ZFW FREQ. THIS CTLR COMMANDED US TO DSND IMMEDIATELY TO FL330 AND INFORMED US OF OPPOSITE DIRECTION TFC AT 5 MI, SAME ALT, CLOSING VERY FAST. I RESPONDED IMMEDIATELY BY DSNDING RAPIDLY TO FL330. THE TFC, CPR Y, WAS SIGHTED VISUALLY AT ABOUT 4 MI AWAY. WE PASSED ABOUT 1/2 MI HORIZ AND 2000 FT VERTICALLY BELOW CPR Y. WE LATER LEARNED THAT CPR Y WAS NOT IN COM CONTACT WITH ZFW. IT WAS EQUIPPED WITH TCASII AND PERFORMED A CLB IN RESPONSE TO AN RA COMMAND. OUR MLG WAS NOT TCASII EQUIPPED. SUPPLEMENTAL INFO FROM ACN 241294: CPR Y DID NOT RECEIVE A CTR FREQ CHANGE, OUR LAST BELIEVED FREQ WAS ZKC ON 132.65. EVEN THOUGH WE HAD FLOWN OUTSIDE OF KANSAS CITY'S AIRSPACE WE DID NOT REALIZE THAT WE HAD LOST COMS WITH KANSAS CITY DUE TO THE FACT THAT WE KEPT HEARING OTHER ACFT ON THE FREQ. WE WERE APPROX 70-100 MI N OF ACT AT FL350 WHEN WE RECEIVED A TCASII TA. WE HAD THE TCASII ON THE 40 MI SCALE AND IN THE NORMAL POS WHICH COVERS 2700 FT ABOVE AND BELOW OUR ALT ON THIS SYSTEM. THERE WAS NO TARGET ON THE TCASII SCREEN UNTIL WE RECEIVED THE ADVISORY AND THE TCASII ALERTED 'TFC, 'TFC.' THE TARGET AT THIS TIME WAS ABOUT 4-6 MI AWAY (THIS IS ACCORDING TO ZFW'S RADAR TAPES WHEN WE STARTED OUR CLB). WE IMMEDIATELY SCANNED THE AREA FOR THE TFC, DID NOT SEE ANYTHING, AND THEN I WENT BACK INSIDE TO LOOK AT THE TCASII AGAIN.(AT THAT MOMENT THE THOUGHT CROSSED MY MIND THAT THIS WAS A FALSE ALERT.) WHEN I LOOKED AT THE TCASII I SAW THE TARGET TURN FROM YELLOW TO RED AND WAS ALERTED 'CLB, CLB' AND WAS PRESENTED WITH A 1500 FPM CLB RESOLUTION. I IMMEDIATELY DISCONNECTED THE AUTOPLT AND CLBED THE ACFT AT THE PRESCRIBED 1500 FPM. AT ABOUT 600 FT ABOVE OUR ALT THE TCASII ALERTED 'MONITOR VERT SPD,' AT THAT TIME I BELIEVE I STOPPED THE CLB. SHORTLY AFTER TCASII ALERTED 'CLR OF CONFLICT' AND I THEN DSNDED BACK TO OUR ASSIGNED ALT OF FL350. WE THEN TRIED TO CALL CTR TO FIND OUT ABOUT THE TFC AND REALIZED THAT WE WERE WELL OUTSIDE OF KANSAS CITY AIRSPACE, HOWEVER BEFORE WE SWITCHED FREQS WE STILL HEARD AN ACFT CHK IN WITH KANSAS CITY, WE WENT TO THE CHART AND FOUND A HIGH ALT WX FREQ CONTACTED THEM AND THEY GAVE US A FREQ FOR ZFW WHO WE THEN CONTACTED. I FEEL THAT AN INCREASED SITUATIONAL AWARENESS AS TO CTR BOUNDARIES ON OUR PART WOULD HAVE AVOIDED THIS SIT ALL TOGETHER, BECAUSE WE WOULD HAVE QUESTIONED CTR ABOUT A FREQ CHANGE FAR SOONER. I ALSO FEEL THAT BEING ABOUT 11 HRS INTO OUR DUTY DAY MIGHT HAVE PLAYED A PART IN OUR BEING LURED INTO A FALSE SENSE OF SECURITY REGARDING COMS. SUPPLEMENTAL INFO FROM ACN 241845: I WAS WORKING THE RADAR ASSOCIATE POS ON A SECTOR 100 MI OR MORE E OF THIS OCCURRENCE. MY INVOLVEMENT IS BECAUSE ACR X WAS PUT ON MY FREQ BY MISTAKE BY ZHU. THE SECTOR I WAS WORKING WAS HEARING OVERLOAD AND A RADAR HDOF CTLR WAS ADDED WITHIN 1 MIN OF WHEN I WAS ADVISED THAT ACR X WAS ERRONEOUSLY SWITCHED TO MY FREQ. I DID NOT HEAR ACR X CHK ON FREQ AND BECAME AWARE THAT HE WAS ON MY FREQ WHEN HE REQUESTED DIRECT IRW. I ADVISED MY R-SIDE TO SWITCH ACR X TO DALLAS HI, THE SECTOR IN WHICH THE ERROR OCCURRED. AT THAT TIME, NEITHER MY R-SIDE NOR I WAS AWARE THAT ACR X WAS IN POTENTIAL CONFLICTION WITH THE CPR Y. CPR Y WAS LOST ON A ZKC FREQ.

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.