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Flight crew reads back clearance, starts descent. Informed clearance was for another aircraft. Airborne conflict.
| Attributes | |
| ACN | 135362 |
| Time | |
| Date | 199001 |
| Day | Tue |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : dfw |
| State Reference | TX |
| Altitude | msl bound lower : 10500 msl bound upper : 11000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : dfw |
| Operator | common carrier : air carrier |
| Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
| Navigation In Use | Other Other |
| Flight Phase | descent : approach |
| Route In Use | arrival star : star |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : flight engineer |
| Experience | flight time last 90 days : 200 flight time total : 11300 flight time type : 1000 |
| ASRS Report | 135362 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : flight engineer pilot : commercial pilot : atp |
| Experience | flight time last 90 days : 240 flight time total : 4000 flight time type : 500 |
| ASRS Report | 135363 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance other anomaly other |
| Independent Detector | other controllera other flight crewa |
| Resolutory Action | flight crew : took evasive action |
| Consequence | Other |
| Miss Distance | horizontal : 0 vertical : 500 |
| Supplementary | |
| Primary Problem | Ambiguous |
| Air Traffic Incident | Operational Deviation Pilot Deviation |
Narrative:
Approaching dfw on boids one approximately 15 mi from the airport, both the first officer and I understood clearance by approach control to descend from 11,000' to 6000', the clearance was read back with no response from the controller and descent was commended. At approximately 10,600' controller issued us a traffic advisory at 'about 11 O'clock, 6 mi at 10,000'', then asked us if we were descending. We replied yes, then the controller said 'that clearance was for someone else, climb immediately to 11,000'!' we initiated an abrupt climb to 11,000' as the approaching aircraft passed below us as we passed through approximately 10,500' climbing. We continued our approach and landed without further incident. Traffic in this approach corridor was particularly dense at the time, and may have contributed to either our misunderstanding the clearance or the controller missing our readback of the clearance.
Original NASA ASRS Text
Title: FLT CREW READS BACK CLRNC, STARTS DESCENT. INFORMED CLRNC WAS FOR ANOTHER ACFT. AIRBORNE CONFLICT.
Narrative: APCHING DFW ON BOIDS ONE APPROX 15 MI FROM THE ARPT, BOTH THE F/O AND I UNDERSTOOD CLRNC BY APCH CTL TO DSND FROM 11,000' TO 6000', THE CLRNC WAS READ BACK WITH NO RESPONSE FROM THE CTLR AND DSCNT WAS COMMENDED. AT APPROX 10,600' CTLR ISSUED US A TFC ADVISORY AT 'ABOUT 11 O'CLOCK, 6 MI AT 10,000'', THEN ASKED US IF WE WERE DESCENDING. WE REPLIED YES, THEN THE CTLR SAID 'THAT CLRNC WAS FOR SOMEONE ELSE, CLIMB IMMEDIATELY TO 11,000'!' WE INITIATED AN ABRUPT CLIMB TO 11,000' AS THE APCHING ACFT PASSED BELOW US AS WE PASSED THROUGH APPROX 10,500' CLIMBING. WE CONTINUED OUR APCH AND LANDED WITHOUT FURTHER INCIDENT. TFC IN THIS APCH CORRIDOR WAS PARTICULARLY DENSE AT THE TIME, AND MAY HAVE CONTRIBUTED TO EITHER OUR MISUNDERSTANDING THE CLRNC OR THE CTLR MISSING OUR READBACK OF THE CLRNC.
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.