 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B737-800 flight crew makes a precautionary descent to comply with a TCASII RA. PIC fails to see a target and ATC confirms the lack of traffic. ZHU, tx.
| Attributes | |
| ACN | 473046 |
| Time | |
| Date | 200005 |
| Day | Mon |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : zhu.artcc |
| State Reference | TX |
| Altitude | msl bound lower : 25600 msl bound upper : 26000 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zhu.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | B737 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 473046 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : instrument pilot : commercial |
| Events | |
| Anomaly | aircraft equipment problem : less severe other anomaly other |
| Independent Detector | aircraft equipment : tcas other flight crewa |
| Resolutory Action | flight crew : overcame equipment problem flight crew : returned to assigned altitude flight crew : took precautionary avoidance action other |
| Consequence | faa : reviewed incident with flight crew other other |
| Supplementary | |
| Problem Areas | Aircraft Flight Crew Human Performance |
| Primary Problem | Aircraft |
Narrative:
Cruising along at FL260, TCASII issued a TA. Almost immediately following was issuance of a descend RA. Autoplt and autothrottles were disconnected and first officer started a descent while I switched my map range selector to the 5 range and looked for traffic. Visually, nothing was in sight. I called ZHU and advised them that we were descending due to TCASII RA. The controller from ZHU said there was no traffic in our area. Total altitude deviation was 400 ft from FL260. Approximately 3 mins later the system did the same thing again. However, this time I elected not to follow the TCASII RA as we were both keenly looking outside and there was no traffic. We switched the TCASII system over to the opposite side for altitude information and other transponder and had no further TCASII advisories. I wrote dispatch an ACARS note saying that I would be writing the system up upon arrival in lax. A logbook entry was indeed made upon arrival in lax.
Original NASA ASRS Text
Title: A B737-800 FLC MAKES A PRECAUTIONARY DSCNT TO COMPLY WITH A TCASII RA. PIC FAILS TO SEE A TARGET AND ATC CONFIRMS THE LACK OF TFC. ZHU, TX.
Narrative: CRUISING ALONG AT FL260, TCASII ISSUED A TA. ALMOST IMMEDIATELY FOLLOWING WAS ISSUANCE OF A DSND RA. AUTOPLT AND AUTOTHROTTLES WERE DISCONNECTED AND FO STARTED A DSCNT WHILE I SWITCHED MY MAP RANGE SELECTOR TO THE 5 RANGE AND LOOKED FOR TFC. VISUALLY, NOTHING WAS IN SIGHT. I CALLED ZHU AND ADVISED THEM THAT WE WERE DSNDING DUE TO TCASII RA. THE CTLR FROM ZHU SAID THERE WAS NO TFC IN OUR AREA. TOTAL ALTDEV WAS 400 FT FROM FL260. APPROX 3 MINS LATER THE SYS DID THE SAME THING AGAIN. HOWEVER, THIS TIME I ELECTED NOT TO FOLLOW THE TCASII RA AS WE WERE BOTH KEENLY LOOKING OUTSIDE AND THERE WAS NO TFC. WE SWITCHED THE TCASII SYS OVER TO THE OPPOSITE SIDE FOR ALT INFO AND OTHER XPONDER AND HAD NO FURTHER TCASII ADVISORIES. I WROTE DISPATCH AN ACARS NOTE SAYING THAT I WOULD BE WRITING THE SYS UP UPON ARR IN LAX. A LOGBOOK ENTRY WAS INDEED MADE UPON ARR IN LAX.
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.