 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B737 first officer reported that after two TCAS advisories with no confirmed traffic in the area; they determined it was an equipment malfunction.
| Attributes | |
| ACN | 1475604 |
| Time | |
| Date | 201708 |
| Place | |
| Locale Reference | ZZZ.ARTCC |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Make Model Name | B737 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Cruise |
| Route In Use | Oceanic |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Traffic Collision Avoidance System (TCAS) |
| Person 1 | |
| Function | First Officer Pilot Flying |
| Experience | Flight Crew Total 1456 Flight Crew Type 785 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe |
Narrative:
Two TCAS resolution advisories (RA) were received while at cruise altitude with no traffic observed or reported in the vicinity. The first incident occurred at [an] altitude [of] FL370. The TCAS system momentarily displayed amber traffic advisory symbols with the 'traffic; traffic' aural warning; followed immediately by the RA directing a climb. The RA continued until the aircraft was flown to approximately FL374. Prior to the event; the TCAS system was not displaying traffic in the vicinity; nor was traffic observed. The RA was immediately reported to ATC. ATC advised that there was no traffic in the immediate vicinity. The second incident occurred [an hour later] while at FL390. Once again there was no traffic observed or displayed by TCAS near the aircraft. During this incident the TCAS again displayed traffic symbology and aural warning; followed by the RA directing a descent. The RA guidance remained until the aircraft descended to FL386. The RA was reported to ATC. ATC advised the nearest traffic was 40NM from our position. During both incidents; transponder #2 was in use. Suspecting an equipment malfunction; the #1 transponder was utilized for the remainder of the flight. A logbook entry was made providing the details. Maintenance elected to defer the #2 transponder for the subsequent flight.
Original NASA ASRS Text
Title: A B737 First Officer reported that after two TCAS advisories with no confirmed traffic in the area; they determined it was an equipment malfunction.
Narrative: Two TCAS Resolution Advisories (RA) were received while at cruise altitude with no traffic observed or reported in the vicinity. The first incident occurred at [an] altitude [of] FL370. The TCAS system momentarily displayed amber traffic advisory symbols with the 'Traffic; Traffic' aural warning; followed immediately by the RA directing a climb. The RA continued until the aircraft was flown to approximately FL374. Prior to the event; the TCAS system was not displaying traffic in the vicinity; nor was traffic observed. The RA was immediately reported to ATC. ATC advised that there was no traffic in the immediate vicinity. The second incident occurred [an hour later] while at FL390. Once again there was no traffic observed or displayed by TCAS near the aircraft. During this incident the TCAS again displayed traffic symbology and aural warning; followed by the RA directing a descent. The RA guidance remained until the aircraft descended to FL386. The RA was reported to ATC. ATC advised the nearest traffic was 40NM from our position. During both incidents; transponder #2 was in use. Suspecting an equipment malfunction; the #1 transponder was utilized for the remainder of the flight. A logbook entry was made providing the details. Maintenance elected to defer the #2 transponder for the subsequent flight.
Data retrieved from NASA's ASRS site 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.