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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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Near midair collision between the rptrs in a B737 descending as assigned on a SID arrival and a cessna crossing underneath them at about 100 ft. ATC advised that they had tried to advise them of the traffic and issue an amended clearance but got no response.
| Attributes | |
| ACN | 374247 |
| Time | |
| Date | 199707 |
| Day | Sun |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : brv airport : iad |
| State Reference | VA |
| Altitude | msl bound lower : 8700 msl bound upper : 9000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : iad |
| Operator | common carrier : air carrier |
| Make Model Name | B737 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | descent other |
| Route In Use | arrival other arrival star : star enroute airway : iad |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Cessna Aircraft Undifferentiated or Other Model |
| Operating Under FAR Part | other : unknown |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 120 flight time total : 6000 flight time type : 250 |
| ASRS Report | 374247 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 200 flight time total : 4700 flight time type : 470 |
| ASRS Report | 374246 |
| Events | |
| Anomaly | conflict : nmac non adherence : required legal separation |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other controllera |
| Resolutory Action | controller : issued new clearance flight crew : took evasive action other |
| Consequence | Other |
| Miss Distance | horizontal : 0 vertical : 100 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
Narrative:
Dulles approach cleared us out of 10000 ft to maintain 5000 ft as we turned to a 330 degree heading from the brv VOR (COATT3 arrival to iad). Completing the turn at about 9000 ft we heard ATC query another aircraft to ask if they could read them. They could. ATC called us as we passed 8800 ft and told us we were to maintain 9000 ft per an updated clearance that we never received (bank of aircraft may have blocked receipt of transmission or controller may have pushed the wrong button). Captain initiated a climb at 8700 ft as we received a TA for traffic below us. TCASII showed 100 ft below us but we never received an RA. TCASII also did not show traffic until we passed 8700 ft in descent. Due to haze and scattered clouds, we never saw the cessna that passed 100 ft below us.
Original NASA ASRS Text
Title: NMAC BTWN THE RPTRS IN A B737 DSNDING AS ASSIGNED ON A SID ARR AND A CESSNA XING UNDERNEATH THEM AT ABOUT 100 FT. ATC ADVISED THAT THEY HAD TRIED TO ADVISE THEM OF THE TFC AND ISSUE AN AMENDED CLRNC BUT GOT NO RESPONSE.
Narrative: DULLES APCH CLRED US OUT OF 10000 FT TO MAINTAIN 5000 FT AS WE TURNED TO A 330 DEG HDG FROM THE BRV VOR (COATT3 ARR TO IAD). COMPLETING THE TURN AT ABOUT 9000 FT WE HEARD ATC QUERY ANOTHER ACFT TO ASK IF THEY COULD READ THEM. THEY COULD. ATC CALLED US AS WE PASSED 8800 FT AND TOLD US WE WERE TO MAINTAIN 9000 FT PER AN UPDATED CLRNC THAT WE NEVER RECEIVED (BANK OF ACFT MAY HAVE BLOCKED RECEIPT OF XMISSION OR CTLR MAY HAVE PUSHED THE WRONG BUTTON). CAPT INITIATED A CLB AT 8700 FT AS WE RECEIVED A TA FOR TFC BELOW US. TCASII SHOWED 100 FT BELOW US BUT WE NEVER RECEIVED AN RA. TCASII ALSO DID NOT SHOW TFC UNTIL WE PASSED 8700 FT IN DSCNT. DUE TO HAZE AND SCATTERED CLOUDS, WE NEVER SAW THE CESSNA THAT PASSED 100 FT BELOW US.
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.