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|
Attributes | |
ACN | 255410 |
Time | |
Date | 199310 |
Day | Sun |
Local Time Of Day | 1201 To 1800 |
Place | |
Locale Reference | atc facility : bpr |
State Reference | TX |
Altitude | msl bound lower : 28000 msl bound upper : 28300 |
Environment | |
Flight Conditions | Mixed |
Light | Daylight |
Aircraft 1 | |
Controlling Facilities | artcc : zfw tower : msp |
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 | arrival other |
Flight Plan | IFR |
Aircraft 2 | |
Operator | common carrier : air carrier |
Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
Flight Plan | IFR |
Person 1 | |
Affiliation | company : air carrier |
Function | flight crew : captain oversight : pic |
Qualification | pilot : flight engineer pilot : atp |
Experience | flight time last 90 days : 70 flight time total : 9300 flight time type : 3000 |
ASRS Report | 255410 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : first officer |
Qualification | pilot : atp pilot : flight engineer |
Experience | flight time last 90 days : 70 flight time total : 9000 flight time type : 640 |
ASRS Report | 255409 |
Events | |
Anomaly | conflict : airborne less severe non adherence : published procedure non adherence : required legal separation |
Independent Detector | other controllera |
Resolutory Action | other |
Consequence | faa : reviewed incident with flight crew |
Miss Distance | horizontal : 21120 vertical : 0 |
Supplementary | |
Primary Problem | ATC Human Performance |
Air Traffic Incident | Operational Error |
Narrative:
Flight had originated in san jose, ca, and was bound for the dfw international airport. We had established ourselves on the boids 3 arrival via texico (txo) and the turki transition and were cruising at FL330. A few mins after establishing ourselves inbound to bpr VOR on the 287 degree radial, ZFW issued us flow control holding clearance. At this time the activity in this controller's sector seemed quite busy. The controller cleared us to the ryann intersection to hold west, as published, using left turns, and at FL280. We were told to expect further clearance at XA12Z and we were authority/authorized for 10 mi legs. As the PF, I initiated a speed reduction to 250 KTS. Ryann intersection is located at 70 DME on the bpr 287 degree radial. A holding pattern is depicted on the boids 3 arrival chart and shows a holding pattern to the west of ryann with left turns. Upon reaching ryann intersection, I initiated a left turn direct entry into the holding pattern and we reported to ZFW that we were at ryann intersection entering the hold and descending to FL280. The controller acknowledged our report with a somewhat garbled response that hinted of bewilderment. The most prudent entry into the holding pattern as depicted and instructed was a direct entry. Using a 25 degree bank angle, I continued my turn to the outbound leg. Upon reaching FL280, I leveled the aircraft and continued my turn to the outbound heading. I had selected a heading of 270 degrees to compensate for the strong southwest wind component. I continued outbound on this heading until reaching our leg limit at 80 DME. As I began my left turn to intercept the holding radial inbound, the controller issued urgent instructions to another aircraft to turn 'immediately' to a heading of 010 degrees. The controller's voice was that of a different controller and its tone showed a sense of concern and urgency. A few moments later, this new controller instructed us to turn to a 260 degree heading. Since I had already established a left turn, I simply rolled out on the 260 degree heading. Shortly after stopping our turn at 260 degrees, we received a TCASII alert from an aircraft at our 12:30 position which had penetrated our TCASII parameters. Following the TCASII commands I began a climb and the first officer alerted the controller that we were responding to a TCASII alert. The controller acknowledged with a sigh and then a comment to the effect that the traffic should pass well clear. After climbing about 300 ft, the TCASII alert subsided and I returned to FL280. During the TCASII alert our traffic conflict close to the edge of our 5 mi range mark. I would estimate that there was no less than 4 mi separation. We continued under radar vectors until we were once again cleared to rejoin the boids 3 arrival. It is possible that the airspace incursion might have been averted if the controller's heading instructions had been worded differently. He had assumed that my outbound heading was 287 degrees and when he instructed me to turn to 260 degrees he was essentially trying to modify my heading by 27 degrees. In reality his instructions really only modified my wind compensated outbound heading by 10 degrees. Had he instructed me to turn 30 degrees left, I would have turned to 240 degrees and the other aircraft may not have penetrated our TCASII parameters. Still this does not address the underlying reasons why 2 aircraft were occupying the same airspace at similar altitudes. It is my impression that the original controller who initially cleared us to the holding fix at ryann intersection was not the same controller who later issued the conflict avoidance vectors to ours and the other aircraft. It is possible that the earlier controller was a controller in the later stages of training and that as a critical situation developed his control was overridden by a supervising controller.
Original NASA ASRS Text
Title: ACR GETS RADAR VECTORS WHILE IN HOLDING PATTERN TO AVOID CLOSE PROX WITH SECOND ACFT.
Narrative: FLT HAD ORIGINATED IN SAN JOSE, CA, AND WAS BOUND FOR THE DFW INTL ARPT. WE HAD ESTABLISHED OURSELVES ON THE BOIDS 3 ARR VIA TEXICO (TXO) AND THE TURKI TRANSITION AND WERE CRUISING AT FL330. A FEW MINS AFTER ESTABLISHING OURSELVES INBOUND TO BPR VOR ON THE 287 DEG RADIAL, ZFW ISSUED US FLOW CTL HOLDING CLRNC. AT THIS TIME THE ACTIVITY IN THIS CTLR'S SECTOR SEEMED QUITE BUSY. THE CTLR CLRED US TO THE RYANN INTXN TO HOLD W, AS PUBLISHED, USING L TURNS, AND AT FL280. WE WERE TOLD TO EXPECT FURTHER CLRNC AT XA12Z AND WE WERE AUTH FOR 10 MI LEGS. AS THE PF, I INITIATED A SPD REDUCTION TO 250 KTS. RYANN INTXN IS LOCATED AT 70 DME ON THE BPR 287 DEG RADIAL. A HOLDING PATTERN IS DEPICTED ON THE BOIDS 3 ARR CHART AND SHOWS A HOLDING PATTERN TO THE W OF RYANN WITH L TURNS. UPON REACHING RYANN INTXN, I INITIATED A L TURN DIRECT ENTRY INTO THE HOLDING PATTERN AND WE RPTED TO ZFW THAT WE WERE AT RYANN INTXN ENTERING THE HOLD AND DSNDING TO FL280. THE CTLR ACKNOWLEDGED OUR RPT WITH A SOMEWHAT GARBLED RESPONSE THAT HINTED OF BEWILDERMENT. THE MOST PRUDENT ENTRY INTO THE HOLDING PATTERN AS DEPICTED AND INSTRUCTED WAS A DIRECT ENTRY. USING A 25 DEG BANK ANGLE, I CONTINUED MY TURN TO THE OUTBOUND LEG. UPON REACHING FL280, I LEVELED THE ACFT AND CONTINUED MY TURN TO THE OUTBOUND HDG. I HAD SELECTED A HDG OF 270 DEGS TO COMPENSATE FOR THE STRONG SW WIND COMPONENT. I CONTINUED OUTBOUND ON THIS HDG UNTIL REACHING OUR LEG LIMIT AT 80 DME. AS I BEGAN MY L TURN TO INTERCEPT THE HOLDING RADIAL INBOUND, THE CTLR ISSUED URGENT INSTRUCTIONS TO ANOTHER ACFT TO TURN 'IMMEDIATELY' TO A HDG OF 010 DEGS. THE CTLR'S VOICE WAS THAT OF A DIFFERENT CTLR AND ITS TONE SHOWED A SENSE OF CONCERN AND URGENCY. A FEW MOMENTS LATER, THIS NEW CTLR INSTRUCTED US TO TURN TO A 260 DEG HDG. SINCE I HAD ALREADY ESTABLISHED A L TURN, I SIMPLY ROLLED OUT ON THE 260 DEG HDG. SHORTLY AFTER STOPPING OUR TURN AT 260 DEGS, WE RECEIVED A TCASII ALERT FROM AN ACFT AT OUR 12:30 POS WHICH HAD PENETRATED OUR TCASII PARAMETERS. FOLLOWING THE TCASII COMMANDS I BEGAN A CLB AND THE FO ALERTED THE CTLR THAT WE WERE RESPONDING TO A TCASII ALERT. THE CTLR ACKNOWLEDGED WITH A SIGH AND THEN A COMMENT TO THE EFFECT THAT THE TFC SHOULD PASS WELL CLR. AFTER CLBING ABOUT 300 FT, THE TCASII ALERT SUBSIDED AND I RETURNED TO FL280. DURING THE TCASII ALERT OUR TFC CONFLICT CLOSE TO THE EDGE OF OUR 5 MI RANGE MARK. I WOULD ESTIMATE THAT THERE WAS NO LESS THAN 4 MI SEPARATION. WE CONTINUED UNDER RADAR VECTORS UNTIL WE WERE ONCE AGAIN CLRED TO REJOIN THE BOIDS 3 ARR. IT IS POSSIBLE THAT THE AIRSPACE INCURSION MIGHT HAVE BEEN AVERTED IF THE CTLR'S HDG INSTRUCTIONS HAD BEEN WORDED DIFFERENTLY. HE HAD ASSUMED THAT MY OUTBOUND HDG WAS 287 DEGS AND WHEN HE INSTRUCTED ME TO TURN TO 260 DEGS HE WAS ESSENTIALLY TRYING TO MODIFY MY HDG BY 27 DEGS. IN REALITY HIS INSTRUCTIONS REALLY ONLY MODIFIED MY WIND COMPENSATED OUTBOUND HDG BY 10 DEGS. HAD HE INSTRUCTED ME TO TURN 30 DEGS L, I WOULD HAVE TURNED TO 240 DEGS AND THE OTHER ACFT MAY NOT HAVE PENETRATED OUR TCASII PARAMETERS. STILL THIS DOES NOT ADDRESS THE UNDERLYING REASONS WHY 2 ACFT WERE OCCUPYING THE SAME AIRSPACE AT SIMILAR ALTS. IT IS MY IMPRESSION THAT THE ORIGINAL CTLR WHO INITIALLY CLRED US TO THE HOLDING FIX AT RYANN INTXN WAS NOT THE SAME CTLR WHO LATER ISSUED THE CONFLICT AVOIDANCE VECTORS TO OURS AND THE OTHER ACFT. IT IS POSSIBLE THAT THE EARLIER CTLR WAS A CTLR IN THE LATER STAGES OF TRAINING AND THAT AS A CRITICAL SIT DEVELOPED HIS CTL WAS OVERRIDDEN BY A SUPERVISING CTLR.
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.