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A B737-800 captain reported that the fmcs are blanking and locking-up.
| Attributes | |
| ACN | 1465034 |
| Time | |
| Date | 201707 |
| Local Time Of Day | 1801-2400 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Make Model Name | B737-800 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Descent Initial Approach |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | FMS/FMC |
| Person 1 | |
| Function | Captain Pilot Flying |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe |
Narrative:
I'm writing to voice a concern I have with the 737 fmcs. I've had three major; and many minor; lock up problems in the past year.each time in the past; I was in VMC weather and went to raw data. I completed the arrival/approach with nothing more than higher workload. This past [event] I encountered wind shear and confusion in the cockpit because the fmcs again went into a mode rendering them inoperative at the worst possible time (magenta line going away; flight directors unusable; FMC key pads locking up; nav data unusable either from blanking or simply not functioning). I've written two of these up and found no satisfaction that the problem would be fixed. I brought this up in recurrent [training] and the instructor found [someone] to explain what was going on. He said it was a software problem and it would be fixed in two months. Six months later; same problems.the so-called momentary blanking; for me and others in the classroom; is a puzzle. It might be 2-3 seconds or 30-40 seconds --you never can tell. This has always happened in high work load areas; not allowing me to troubleshoot the system -- if it's even possible.I have 31 years of FMC aircraft experience and never found it this bad. To say I'm having trust issues with the fmcs is an understatement.
Original NASA ASRS Text
Title: A B737-800 Captain reported that the FMCs are blanking and locking-up.
Narrative: I'm writing to voice a concern I have with the 737 FMCs. I've had three major; and many minor; lock up problems in the past year.Each time in the past; I was in VMC weather and went to raw data. I completed the arrival/approach with nothing more than higher workload. This past [event] I encountered wind shear and confusion in the cockpit because the FMCs again went into a mode rendering them inoperative at the worst possible time (magenta line going away; flight directors unusable; FMC key pads locking up; nav data unusable either from blanking or simply not functioning). I've written two of these up and found no satisfaction that the problem would be fixed. I brought this up in recurrent [training] and the instructor found [someone] to explain what was going on. He said it was a software problem and it would be fixed in two months. Six months later; same problems.The so-called momentary blanking; for me and others in the classroom; is a puzzle. It might be 2-3 seconds or 30-40 seconds --you never can tell. This has always happened in high work load areas; not allowing me to troubleshoot the system -- if it's even possible.I have 31 years of FMC aircraft experience and never found it this bad. To say I'm having trust issues with the FMCs is an understatement.
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.