B777-200
Flight Crew Air Transport Pilot (ATP)
Confusion; Distraction; Human-Machine Interface; Troubleshooting
Deviation - Speed All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew FLC Overrode Automation; Flight Crew Returned To Clearance
Aircraft; Human Factors; Manuals; Procedure; Logbook Entry
I have been informed of an intent to file a deviation report on me for exceeding 250 knots below 10;000 feet on the subject flight. I was one of two relief pilots on this flight and I cannot specifically recall if I was in the first observer's seat or second observer's seat. I also do not recall which pilot was the pilot flying or which the pilot monitoring on this flight. I had no recollection of this event until I reviewed the maintenance history of the aircraft which jogged my memory somewhat. I recall that there was an issue with the FMC and that its response based on programmed entries was not expected by the crew. I believe one or more crew members immediately commented so that immediate correction was made; but not before the exceedance. The Captain wrote up the discrepancy upon arrival at the gate. Obviously; I/we should have immediately associated this with an event requiring an ASAP report.I believe [the cause of this event] was an unexpected response of the aircraft automation to pilot input into FMC. Obviously; the crew must be responsive to quickly correct even unexpected aircraft deviations. I think the pilot flying was immediately responsive to this event; as I recall; correcting the deviation to the best of human capabilities.Obviously we all should have discussed submission of a safety report. If others submitted one they were smarter than me. I would never intentionally violate operating rules; and I take this very seriously. In the future I will recall this event and even if any doubt exists; submit a safety report.
I am submitting this report in response to an email I received yesterday from [the company] Flight Safety Advisor. The purpose of his email was to notify me of the FAA intent to file a pilot deviation against the crew of [our flight from almost a month ago]. The purpose of this report is to more fully explain a situation that occurred during operations in the arrival terminal area shortly before landing. As this event occurred almost one month ago; all details are to the best of my recollection. All operations until arrival were normal and accomplished as expected. When we were in the approach environment the aircraft was connected to the autopilot and following FMS navigation and vertical profile parameters (VNAV Selected). As I was monitoring the descent the aircraft began to make its turn over one of the inbound waypoints; it suddenly leveled its wings and began to turn in the wrong direction. I took immediate action by disconnecting the autopilot; extending full speed brakes and arresting the descent; which had dipped below 10;000 feet. The quick action caused my First Officer to remark; 'It's good that you caught it right away.' I continued the approach manually and landed without incident. ATC made no mention of a possible deviation. After shutdown checks were completed the entire crew participated in an extensive de-brief; discussing the flight anomaly that happened. This strange event was seen by all as highly unusual in the combined experience of all four crewmembers. Of course; we suspected an autopilot/FMS system failure and I squawked it for Maintenance to sort out. My logbook entry appeared as follows: DURING RNAV ARRIVAL AIRCRAFT WAS LATE IN TURNING OVER A PATICULAR WAYPOINT AND EXCEEDED 250 KNOTS BELOW 10;000 WITH VNAV ENGAGED.  I honestly don't recall the precise numbers to the knot and foot; but I think we momentarily exceeded 250 knots below 10;000 feet due to the systems failure. To support this [assertion] I would like to direct your attention to the maintenance logbook entry in response to mine [which includes the statement] 'BOEING IS AWARE OF PROBLEM PER TECH TIP XX-XXXX. ...INTERMITTENT FAULT OK TO CONTINUE... Of particular note in [the maintenance] response is the entry that reads: 'BOEING IS AWARE OF PROBLEM PER TECH TIP...  [which referenced the following:] 'Uncommanded Turn in LNAV Due to Premature Sequencing of TO Waypoint Originated: 18-Sep-2010.' Because this article is labeled BOEING PROPRIETARY; CONFIDENTIAL; AND/OR TRADE SECRET I will not reproduce it here. Suffice it to say this document; which has been in the system for some time; essentially details what occurred on our flight. In this case; the real event was the [anomalous event specified] in my logbook entry to describe an aircraft system anomaly wherein the automation did not function as expected. The intent of the language used describing the malfunction was to use terms I believed to be well understood by mechanics that are familiar with the flight profile of the B-777. I chose those terms merely to show the aircraft behaved unusually with respect to known parameters in a clear and concise way to help direct them to the most likely source(s) of the problem.Well; in reference to B-777 automation; apparently Boeing has an ongoing program (Reference Tech Ref ATA:22-10) to address uncommanded turns while LNAV is in use. However; with regard to logbook entries; flight crews may need to be cautioned about accurately detailing the actual flight performance of their aircraft if in so doing they find themselves subject to an investigation for disclosing what is believed to be essential information needed to accurately describe aircraft system anomalies that deserve attention. It would be counterproductive to all flight safety initiatives to foster an environment where the flight crew is reticent to accurately document problems with the aircraft. An unintended consequence may be the truncating of certain data that could be useful towards the overall maintenance/safety effort.
Three weeks after the 'event' the FAA sought retribution from a B-777 flight crew for exceeding 250K below 10;000 on arrival at their destination.  The source of their information was a routine review of the AML in which the flight crew had written up anomalous behavior of the autoflight system while operating with the autopilot engaged in LNAV and VNAV modes.  The anomalous behavior described consisted of turning the wrong way at a waypoint and exceeding 250 knots below 10;000 feet.  Both anomalous actions were immediately resolved by the crew and; again; written up in the AML.