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B737 on descent for sjc experienced TCAS RA at FL190 with unrpted traffic.
| Attributes | |
| ACN | 694448 |
| Time | |
| Date | 200604 |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | navaid : sns.vortac |
| State Reference | CA |
| Altitude | msl single value : 19000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : nct.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | B737-700 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | descent : intermediate altitude |
| Route In Use | arrival star : robie2 |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Cessna Citation Undifferentiated or Other Model |
| Operating Under FAR Part | Part 91 |
| Flight Phase | climbout : intermediate altitude |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Experience | flight time last 90 days : 233 flight time total : 25000 flight time type : 20000 |
| ASRS Report | 694448 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Experience | flight time last 90 days : 180 flight time total : 6000 flight time type : 3000 |
| ASRS Report | 694526 |
| Events | |
| Anomaly | conflict : airborne critical |
| Independent Detector | aircraft equipment : tcas other flight crewa other flight crewb |
| Resolutory Action | flight crew : took evasive action |
| Miss Distance | horizontal : 10000 vertical : 100 |
| Supplementary | |
| Problem Areas | ATC Human Performance |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Inter Facility Coordination Failure |
Narrative:
On descent on robie arrival into sjc; crossing restr of 15 NM south of sns at FL200. During the descent; frequency change to another controller who gave us a descent to 15000 ft; leaving FL190; we were cleared direct to gilro. We were descending through FL200 towards FL190. The first officer was bringing direct to gilro up to the top of the legs page so we could go direct to gilro passing FL190. Approaching FL190 we received a TA for traffic about 10 O'clock position low; several mi away. I slowed the rate of descent to look for the traffic. I couldn't locate the traffic visually. We then received an RA climb; which I began to climb. The controller then gave us a right turn of approximately 20 degrees. At about FL200; the TCAS gave a clear of conflict. I finally had a visual contact on the aircraft at about 9 O'clock position several mi away. We continued the descent to an uneventful landing. The flight attendants nor any passenger questioned the maneuver; so they were apparently unaware of the event. I guess the first controller gave us the descent to FL200 because the eventual traffic conflict was climbing to FL190. I think the next controller forgot about the FL190 aircraft when he gave us the descent to 15000 ft and the turn to gilro or thought there would be enough lateral separation because of the turn. I know the second controller gave us an 'out of FL190; cleared direct to gilro;' so we must have had the clearance below FL200. If we didn't have a clearance below FL200; the second controller never questioned our descent below FL200 so I don't think we violated any clrncs. The TCAS did its job.
Original NASA ASRS Text
Title: B737 ON DSCNT FOR SJC EXPERIENCED TCAS RA AT FL190 WITH UNRPTED TFC.
Narrative: ON DSCNT ON ROBIE ARR INTO SJC; XING RESTR OF 15 NM S OF SNS AT FL200. DURING THE DSCNT; FREQ CHANGE TO ANOTHER CTLR WHO GAVE US A DSCNT TO 15000 FT; LEAVING FL190; WE WERE CLRED DIRECT TO GILRO. WE WERE DSNDING THROUGH FL200 TOWARDS FL190. THE FO WAS BRINGING DIRECT TO GILRO UP TO THE TOP OF THE LEGS PAGE SO WE COULD GO DIRECT TO GILRO PASSING FL190. APCHING FL190 WE RECEIVED A TA FOR TFC ABOUT 10 O'CLOCK POS LOW; SEVERAL MI AWAY. I SLOWED THE RATE OF DSCNT TO LOOK FOR THE TFC. I COULDN'T LOCATE THE TFC VISUALLY. WE THEN RECEIVED AN RA CLB; WHICH I BEGAN TO CLB. THE CTLR THEN GAVE US A R TURN OF APPROX 20 DEGS. AT ABOUT FL200; THE TCAS GAVE A CLR OF CONFLICT. I FINALLY HAD A VISUAL CONTACT ON THE ACFT AT ABOUT 9 O'CLOCK POS SEVERAL MI AWAY. WE CONTINUED THE DSCNT TO AN UNEVENTFUL LNDG. THE FLT ATTENDANTS NOR ANY PAX QUESTIONED THE MANEUVER; SO THEY WERE APPARENTLY UNAWARE OF THE EVENT. I GUESS THE FIRST CTLR GAVE US THE DSCNT TO FL200 BECAUSE THE EVENTUAL TFC CONFLICT WAS CLBING TO FL190. I THINK THE NEXT CTLR FORGOT ABOUT THE FL190 ACFT WHEN HE GAVE US THE DSCNT TO 15000 FT AND THE TURN TO GILRO OR THOUGHT THERE WOULD BE ENOUGH LATERAL SEPARATION BECAUSE OF THE TURN. I KNOW THE SECOND CTLR GAVE US AN 'OUT OF FL190; CLRED DIRECT TO GILRO;' SO WE MUST HAVE HAD THE CLRNC BELOW FL200. IF WE DIDN'T HAVE A CLRNC BELOW FL200; THE SECOND CTLR NEVER QUESTIONED OUR DSCNT BELOW FL200 SO I DON'T THINK WE VIOLATED ANY CLRNCS. THE TCAS DID ITS JOB.
Data retrieved from NASA's ASRS site as of January 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.