 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B777's number one radio switched between the communication head's two selected frequencies uncommanded. ATC contacted the crew on 121.5 to tell them of the lost communications.
| Attributes | |
| ACN | 951363 |
| Time | |
| Date | 201105 |
| Local Time Of Day | 0001-0600 |
| Place | |
| Locale Reference | ZZZ.ARTCC |
| State Reference | US |
| Environment | |
| Light | Dawn |
| Aircraft 1 | |
| Make Model Name | B777 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent |
| Route In Use | Oceanic |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | VHF |
| Person 1 | |
| Function | First Officer |
| Person 2 | |
| Function | Captain |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe |
Narrative:
Just prior to top of descent; and again during the descent; we lost communications with center due to the number one radio switching itself between the active frequency (133.5) and the frequency in the right side of the same box (121.5). In both cases ATC eventually contacted us on 121.5 to tell us that they wanted us back on 133.5. After the second time we started using the right side radio and monitored the left one. All three pilots subsequently witnessed the left radio do it again (switch itself from 133.5 to 121.5). We wrote the left radio up and continued flight uneventfully with the right side radio.
Original NASA ASRS Text
Title: A B777's number one radio switched between the communication head's two selected frequencies uncommanded. ATC contacted the crew on 121.5 to tell them of the lost communications.
Narrative: Just prior to top of descent; and again during the descent; we lost communications with Center due to the number one radio switching itself between the active frequency (133.5) and the frequency in the right side of the same box (121.5). In both cases ATC eventually contacted us on 121.5 to tell us that they wanted us back on 133.5. After the second time we started using the right side radio and monitored the left one. All three pilots subsequently witnessed the left radio do it again (switch itself from 133.5 to 121.5). We wrote the left radio up and continued flight uneventfully with the right side radio.
Data retrieved from NASA's ASRS site as of April 2012 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.