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B777 flight crew experiences several false TCAS ras for co-altitude traffic; commanding a descent. In each incident ATC advised there was no traffic nearby.
| Attributes | |
| ACN | 1258793 |
| Time | |
| Date | 201504 |
| Local Time Of Day | 1201-1800 |
| Place | |
| Locale Reference | CZQX.ARTCC |
| State Reference | NF |
| Environment | |
| Flight Conditions | VMC |
| Aircraft 1 | |
| Make Model Name | B777 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Cruise |
| Route In Use | Oceanic |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | TCAS Equipment |
| Person 1 | |
| Function | Pilot Flying First Officer |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Experience | Flight Crew Last 90 Days 250 Flight Crew Total 22000 Flight Crew Type 10000 |
| Person 2 | |
| Function | Relief Pilot Pilot Not Flying First Officer |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Experience | Flight Crew Last 90 Days 100 Flight Crew Total 11000 Flight Crew Type 35 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Deviation - Altitude Excursion From Assigned Altitude |
Narrative:
On north atlantic track east; in VHF contact with gander domestic. Level cruise at FL380. RA event with 'descend; descend!' we did at approximately at FL378 the warning went away. We were stable at FL377. Notified gander they had no traffic close. Only traffic was at FL390 at about 5 NM in our 11 o'clock position. We reengaged autopilot and claimed back to FL380. We notified the captain who was on break. The event was written up in the maintenance log with a '0' for frm item. On descent the flying crew experienced the same event at a lower altitude. Again no traffic in the vicinity.
Original NASA ASRS Text
Title: B777 flight crew experiences several false TCAS RAs for co-altitude traffic; commanding a descent. In each incident ATC advised there was no traffic nearby.
Narrative: On North Atlantic Track E; in VHF contact with Gander Domestic. Level cruise at FL380. RA event with 'Descend; Descend!' We did at approximately at FL378 the warning went away. We were stable at FL377. Notified Gander they had no traffic close. Only traffic was at FL390 at about 5 NM in our 11 o'clock position. We reengaged autopilot and claimed back to FL380. We notified the Captain who was on break. The event was written up in the maintenance log with a '0' for FRM item. On descent the flying crew experienced the same event at a lower altitude. Again no traffic in the vicinity.
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.