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An air carrier aircraft in holding reports a loss of separation with another air carrier aircraft; both assigned FL390.
| Attributes | |
| ACN | 778551 |
| Time | |
| Date | 200803 |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : zfw.artcc |
| State Reference | TX |
| Altitude | msl single value : 39000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zfw.artcc tower : zzz.tower |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Transport |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other vortac |
| Flight Phase | cruise : holding |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zfw.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Large Transport |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 778551 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial |
| ASRS Report | 778677 |
| Events | |
| Anomaly | conflict : airborne critical non adherence : published procedure |
| Independent Detector | aircraft equipment : tcas other flight crewa other flight crewb |
| Resolutory Action | controller : issued alert flight crew : took evasive action |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Problem Areas | ATC Human Performance Airspace Structure |
| Primary Problem | ATC Human Performance |
Narrative:
We were en route to dfw. Filed altitude was 37000 ft. We were rerouted due to WX in dfw. We were asked by ZFW if we could accept FL390 for traffic. By this time we were light enough to climb to FL390 and we advised ATC that we could accept FL390. We were cleared to FL390 and advised to copy holding instructions. We were cleared to hold maintain FL390; 20 mile legs. The instructions were accepted and ATC was advised that due to the high altitude we would be turning wider than normal due to the fact that we had to use 1/2 bank due to the high altitude; ATC acknowledged. Nearing completion of the first turn in holding I noted another aircraft at our altitude approximately 10 miles away on TCAS. I was not focused on that AC and assumed it was on a diverging course. A few moments later I noticed it was about 6 miles away. I was ready to take evasive action when ATC issued clearance 'air carrier X turn hard right heading 290 descend and maintain FL380.' it was about this time that TCAS issued a 'traffic traffic' TA. I disconnected the autopilot; forcefully pushed the nose over to unload the wings so I could execute a 30 degree bank at high altitude. We executed the turn and descent with no further difficulties. The first officer inquired on the radio to ATC 'what just happened' and the response was 'I don't know.' I do not know why the event occurred. We were on the protected side of the hold; but since we were turning wider than normal due to the 1/2 bank I'm not sure if ATC expected us to be in a different position.supplemental information from acn 778677: center issued multiple apologies to us on the frequency we were on and the subsequent frequency we were assigned. ZFW directed two aircraft into converging flight paths at the same altitude. They created a loss of separation and near midair collision. This is the second time in less than 6 months that I've had a loss of separation directly resulting from mistakes made by ZFW. This needs to stop.
Original NASA ASRS Text
Title: AN ACR ACFT IN HOLDING RPTS A LOSS OF SEPARATION WITH ANOTHER ACR ACFT; BOTH ASSIGNED FL390.
Narrative: WE WERE ENRTE TO DFW. FILED ALTITUDE WAS 37000 FT. WE WERE REROUTED DUE TO WX IN DFW. WE WERE ASKED BY ZFW IF WE COULD ACCEPT FL390 FOR TFC. BY THIS TIME WE WERE LIGHT ENOUGH TO CLIMB TO FL390 AND WE ADVISED ATC THAT WE COULD ACCEPT FL390. WE WERE CLRED TO FL390 AND ADVISED TO COPY HOLDING INSTRUCTIONS. WE WERE CLRED TO HOLD MAINTAIN FL390; 20 MILE LEGS. THE INSTRUCTIONS WERE ACCEPTED AND ATC WAS ADVISED THAT DUE TO THE HIGH ALTITUDE WE WOULD BE TURNING WIDER THAN NORMAL DUE TO THE FACT THAT WE HAD TO USE 1/2 BANK DUE TO THE HIGH ALTITUDE; ATC ACKNOWLEDGED. NEARING COMPLETION OF THE FIRST TURN IN HOLDING I NOTED ANOTHER ACFT AT OUR ALTITUDE APPROX 10 MILES AWAY ON TCAS. I WAS NOT FOCUSED ON THAT AC AND ASSUMED IT WAS ON A DIVERGING COURSE. A FEW MOMENTS LATER I NOTICED IT WAS ABOUT 6 MILES AWAY. I WAS READY TO TAKE EVASIVE ACTION WHEN ATC ISSUED CLRNC 'ACR X TURN HARD RIGHT HEADING 290 DSND AND MAINTAIN FL380.' IT WAS ABOUT THIS TIME THAT TCAS ISSUED A 'TRAFFIC TRAFFIC' TA. I DISCONNECTED THE AUTOPILOT; FORCEFULLY PUSHED THE NOSE OVER TO UNLOAD THE WINGS SO I COULD EXECUTE A 30 DEG BANK AT HIGH ALTITUDE. WE EXECUTED THE TURN AND DSCNT WITH NO FURTHER DIFFICULTIES. THE FO INQUIRED ON THE RADIO TO ATC 'WHAT JUST HAPPENED' AND THE RESPONSE WAS 'I DON'T KNOW.' I DO NOT KNOW WHY THE EVENT OCCURRED. WE WERE ON THE PROTECTED SIDE OF THE HOLD; BUT SINCE WE WERE TURNING WIDER THAN NORMAL DUE TO THE 1/2 BANK I'M NOT SURE IF ATC EXPECTED US TO BE IN A DIFFERENT POSITION.SUPPLEMENTAL INFO FROM ACN 778677: CENTER ISSUED MULTIPLE APOLOGIES TO US ON THE FREQUENCY WE WERE ON AND THE SUBSEQUENT FREQUENCY WE WERE ASSIGNED. ZFW DIRECTED TWO ACFT INTO CONVERGING FLT PATHS AT THE SAME ALTITUDE. THEY CREATED A LOSS OF SEPARATION AND NEAR MIDAIR COLLISION. THIS IS THE SECOND TIME IN LESS THAN 6 MONTHS THAT I'VE HAD A LOSS OF SEPARATION DIRECTLY RESULTING FROM MISTAKES MADE BY ZFW. THIS NEEDS TO STOP.
Data retrieved from NASA's ASRS site as of May 2009 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.