Page Links: Index Page
| JG1
June 12, 2025, 17:19:00 GMT permalink Post: 11899499 |
Looking at the video of the takeoff roll, it seemed normal, normal rotation, normal initial climb. Other incidents with incorrect performance data or incorrect flap setting (especially flapless) resulted in an extended rotation phase, often with a tailstrike which doesn't seem to be the case here. So the flaps were probably set correctly.
This aircraft then climbed okay but then 3 things happened 1. They didn't raise the gear (maybe due distraction) 2. They apparently called a mayday for an engine problem 3. The aircraft started to sink and continued to do so until ground impact The videos and the flight path don't seem to show lateral deviation or rudder application but if they called mayday for an engine problem we've got to go with that. Perhaps the flaps were retracted early but I don't see any pitch change, just sink. As the aircraft is certified to fly on a single engine, it should have done so. That it didn't seems to indicate that the other engine also stopped developing the required thrust. Whether it was shut down unintentionally or damaged due to some environmental factor remains to be seen but my moneys on inadvertent shutdown. Subjects (links are to this post in the relevant subject page so that this post can be seen in context): MAYDAY Takeoff Roll |
| JG1
June 12, 2025, 19:05:00 GMT permalink Post: 11899613 |
nothing was normal the plane rotated right at the end of the runway far too late and barely climbed at all for 10 seconds before falling 20 seconds and finally crashing 30 seconds after take off.
The most obvious answer is low power/flaps setting if the engines were weird they would have probably aborted take off. Bird strike/engine issue during take off roll after v1? Super unlikely but never say never
"engine issue during take off roll after v1?
Super unlikely but never say never" Last edited by T28B; 12th June 2025 at 19:10 . Reason: quote whom you quoted Subjects (links are to this post in the relevant subject page so that this post can be seen in context): MAYDAY |
| JG1
June 12, 2025, 19:10:00 GMT permalink Post: 11899623 |
Subjects: None |
| JG1
June 13, 2025, 02:37:00 GMT permalink Post: 11899937 |
no way even with balanced engine performance you do not take off with no runway to spare you always leave some margin something was wrong from the start, whether that being flaps (which look like it from pics) or derated engine thrust. Something else may have happened, let\x92s see. Whatever the case that was not a normal take off roll
You don't know what you're talking about. Kindly consider your posts before wasting our collective time. Subjects: None |
| JG1
June 13, 2025, 12:13:00 GMT permalink Post: 11900427 |
One thing which could cause simultaneous unexpected idle power is the autothrottle. I'm thinking about this, leading to a crew too startled to retract the gear and too distracted to push the thrust levers forward, as a possible cause. As others have said, the RAT could have been manually deployed - an action which would make sense to pilot convinced that he was about to lose both engine driven generators.
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Generators/Alternators RAT (All) |
| JG1
June 13, 2025, 12:22:00 GMT permalink Post: 11900444 |
Here is a very unlikely scenario. It may be possible that there was nothing wrong with the aircraft.
We have been told the experience levels of the pilots but not how long they have been flying the 787. The 787 is very automatic and, in my experience, the easiest aircraft to fly. It does a lot of things for you and reminds you of things that you may have forgotten to do. For that reason, in my opinion it is also the safest aircraft around. However, you have to understand what the automatics are doing in order to manage it correctly. By putting the departure route into the FMC you set up the lateral navigation and also the vertical navigation including speeds and altitudes. After take-off the FMC will command you initially to fly at up to V2 + 20 until flap retraction ( normally no lower than 1000 feet agl), and then increase the speed with flap retraction until initial climb speed and then final climb speed above FL 100. If your first altitude restriction on departure is 4000 feet (which will be in the FMC) and VNAV is engaged you will level at 4000 feet. But, if prior to departure, you put 3000 feet in the altitude window (maybe as instructed by ATC) the aircraft will level at 3000 feet. If I remember correctly LNAV engages at 50 feet and VNAV engages at 400 feet agl. And, I may be mistaken, but I think that the auto-pilot could be engaged at 100 feet agl. Now, I am probably wrong about this, but if you forget to set the altitude window to the first altitude in departure and leave it at 0 (which with some airlines the previous crew will do on shutdown) the following might possibly occur. At 50 feet LNAV engages, at 100 feet the autopilot engages, at 400 feet VNAV engages but as the altitude window is set to 0 the aircraft (on autopilot) now descends to capture 0 feet. The speed at this point in VNAV is low (max V2 + 20 kts) so, to maintain that, both thrust levers close. This, of course, would be totally unexpected and could have a startle effect. If you do not realise what has caused this you might think that there is a problem with the engines and you have very little time to deal with it. I would suggest that putting out a Mayday call at this stage is not a good use of time. As I stated at the beginning this is probably very unlikely and may not be possible, but could be tried in a simulator. Last edited by JG1; 13th June 2025 at 13:15 . Subjects (links are to this post in the relevant subject page so that this post can be seen in context): MAYDAY Startle Effect V2 |
| JG1
June 15, 2025, 13:30:00 GMT permalink Post: 11902476 |
A little bit tangential here, thinking about this Mayday call (the exact contents of which haven't been verified, but have been variously reported as "no power", or "lost power" ) , if in front of you on the PFD, in large red letters, you have the words ENG FAIL, why would you say, "no power"? Seems a bit strange. Why not say "engine failure" or "no thrust"?
Could it be that "No power" may have meant the whole cockpit went dark? ie. A total electrical failure or huge short (survivor's bang) initiating RAT deployment and apu autostart. Doesn't explain loss of thrust explicitly but if there was a massive electrical issue, and critical data was lost (thinking air/ground switch position and other fundamentals), would dual engine shutdown be a possibility? Simultaneous FADEC failure? Exceptionally remote possibility perhaps, but by definition these accidents are exceptionally remote. If the RAT deployed we know there was definitely an electrical issue - how bad was it, though? Thinking about the possibility of an electrical failure causing an engine (and instrumentation) failure rather than the other way around. Over to the experts on this. Last edited by JG1; 15th June 2025 at 14:20 . Subjects (links are to this post in the relevant subject page so that this post can be seen in context): Dual Engine Failure Electrical Failure Engine Failure (All) Engine Shutdown FADEC MAYDAY RAT (All) RAT (Deployment) |
| JG1
June 15, 2025, 14:38:00 GMT permalink Post: 11902512 |
The 787 is reliant on good electrical power and plenty of it and we have signs of electrical system failures on this 787. We have a RAT deployed. We have data loss. We have previous flight reports of electrical problems in the cabin. We have a survivor report of lights flickering and a bang - which could well be the RAT deploying.
Subjects (links are to this post in the relevant subject page so that this post can be seen in context): RAT (All) RAT (Deployment) |
| JG1
June 16, 2025, 05:33:00 GMT permalink Post: 11903108 |
https://www.washingtonpost.com/busin...boeing-switch/
Seat movement cannot be discounted. There have been several such incidents affecting the 787 Subjects: None |
| JG1
June 16, 2025, 05:45:00 GMT permalink Post: 11903112 |
If there was water in the E&E bay, the pitch angle change at rotation would cause said water to move (backwards, upwards, slop, splash) and that is exactly when then problems on this flight started, and apparently the point where the surviving passenger heard a bang (elect short?) and the cabin lights flickered (change of elec source).
Captain's mayday says "no power", he means no electric power, engines have rolled back due some internal system failure for sure, because no external factors have caused them to fail. And all internal systems are.... Electric Subjects (links are to this post in the relevant subject page so that this post can be seen in context): MAYDAY |
| JG1
June 16, 2025, 05:57:00 GMT permalink Post: 11903121 |
Could it be possible that in the software the 'position-eng-fuel-switch-left' =ON and the 'position-eng-fuel-switch-right=ON' can both changed to OFF by a electric/software issue? So without movement of the actual physical switches the system senses a shutdown command?
Subjects: None |
Page Links: Index Page