Ahhh, the interesting details. Something was designed to function in one way, but it may have not. The problem was identified, Boeing notifies airlines about it. Then, airlines have to stop operating the aircraft while it’s fixed.
Determining all this takes time. Communications between Boeing and airline, maintenance records, checking other airplanes operating right now with the same issue, finding the switch (es) of the crashed plane, etc.
There is a lot to be investigated based from the logs on the data recorder. A single data point is not enough to tell why something happened.
PS. Travelled 10 hours in a 787 earlier this week and I’m alive
I feel this is a red herring since its very simple to know whether the fuel switch locking feature was faulty or disengaged e.g. entries in the aircraft technical log or better still interview the previous flight crew who had arrived earlier that morning from Delhi.
Exactly. You can read the original report on the Guardian website. There is a photo of the throttle block recovered from the crash with the fuel switches below(page 10). We can safely assume that they checked those, and since they don’t mention not finding it, most certainly the “locking” feature was there as expected…
Yes, they can easily see if the switch lock was there. Also, they said that the throttles were fully forward until impact, but after impact they were found back in the idle position. If the switches were faulty and not locked, able to just slip backwards with the brush of a hand, you’d think they’d also move backwards at impact - yet they were found in the forward run position.
I feel they’ve left out known details, such as which pilot said what and that the switches were functioning to hide the truth for whatever reason (pilot family protection maybe) for a little longer.
1st reference is to the throttles, 2nd is to the fuel switches.
One might expect the throttles to be fully forward with the Pilot attempting to recover thrust. On the other hand the impact might have caused them to be pulled back to idle.
The fuel switches had been reported as being set to cut off shortly after takeoff yet the debris has them in the run position.
The throttles were fully forward according to the data recorder until the moment of impact. But they were recovered back in the idle position, they had ben pushed back at impact.
The fuel switches according to the data recorder were moved backwards to off, then 10 seconds later moved forward to on. If they were faulty and not locked in position, you’d expect they may also be pushed backward like the throttles at impact, but they were not.
One pilot noticed they were off and turned them back on again. They were off for only around 10 seconds or so, but it was too late given how low the plane was.
The report nowhere clearly states that the fuel control switches were indeed moved by either of the pilots during take-off. It just says that they “transitioned” from RUN to CUTOFF based on the black box data. Some pilots and experts have said that the investigators must also closely examine the possibility of an electrical or software malfunction signalling to the aircraft system that the switches were in cut-off mode without being physically moved.
The fact that the preliminary report has not issued any recommendation to the operators of the Boeing 787 aircraft and the GE GEnx-1B engines suggests that the investigators, at least for the time being, do not have sufficient reason to believe that an electrical or system malfunction could have led to the fuel control switches “transitioning” to CUTOFF.
It is worth noting that the preliminary report is only an account of the initial findings of the investigation, and is subject to change on the basis of the progress of the probe over the coming months. Aircraft are extremely sophisticated and complex machines, and detailed and painstaking investigations are required to ascertain the exact cause or combination of causes. The odds that an aviation accident has a single trigger are rare, and crashes usually have a series of things that go wrong together or one leading to another. The AAIB is expected to release the final probe report within a year of the crash, as per international guidelines.
Yes but ICAO recommended practices provide that an interim report be issued within a month. This often results in more questions than answers. A final report should be issued within 12 months.
one pilot asked the other, “Why did you cut off?”—to which the other replied, “I didn’t do so”. While this suggests a physical observation of the switches it is not definitive. It could have been asked from observing the performance of the engines.
The pilot, presumably the one who asked the question, then reset the switches, so it’s clear that they must have been physically moved otherwise he could not have physically moved them back.
Both the switch setting off and then on and the engine thrust, which had started to increase on one engine, also record the fact that they were switched off and then switched back on again.
