Posts about: "Flaps (All)" [Posts: 165 Pages: 9]

My money is on hot, heavy, engine failure and PNF raises flaps instead of gear for now

Intriguing: agree it doesn't look like an inadvertent flap-less take-off, but having watched the video several times, I can’t see any sign of a pitch-down input (ie, less pitch up) that would surely be evident following a dual engine failure. Even if the loss of almost full power from underslung engines didn't naturally cause a change of pitch (FBW), surely the first instinctive control input following such a large loss of thrust would be to lower the nose a little.

Conversely, the rapid sinking feeling induced by the inadvertent Flap retraction at the Gear-up point could confuse the senses and be interpreted as a loss of thrust?

Tragic whatever the cause; I’m sure we'll have the answer fairly soon.

Wow love the theories. Ok why was the gear still down. Under all circumstances that comes up with positive rate. Can\x92t see the flaps but sure looks like they were retracted instead of gear coming up.

engine failure. Sure that would suck lift out but all parameters take thay into effect with the proper flap setting. And you can\x92t take off without the right flap setting per the performance data unless you ignore it.

Loss of lift. VNAV engages at 400 ft and targets airspeed in MCP.

Airboard, do you fly the 787?

Yes. But I have not flown this scenario in the sim. Way too many protection to take off without proper configuration which leads me to believe loss of lift due to flap retraction. 1100 hr FO ……..

From the airport CCTV video it looks to me like a normal takeoff and start of climb, until suddenly there's a loss of climb performance with no obvious upset at that point. From the picture of the wing post crash it looks like the flaps were still deployed (N.B. based on pre-accident photos that's the right wing so closest to the camera is aileron and flaps are further away, damage had me confused first time), so I'm going with loss of thrust rather than flap retraction.

From the videos from bystanders it looks like RAT deployment (both sound and zoomed in pictures) rather than thrust lever retard, and that would also explain failure to retract gear - if you are dealing with both engines out at that altitude then gear isn't your first thought. From the airport CCTV video I don't see anything that looks like bird strikes at that point in the climb i.e. no obvious flocks of birds, no smoke out of the engines, no slewing one way as one engine fails and then the other is cut by accident - plus you wouldn't cut the engine at that point, you'd climb on one engine and then sort it out.

Even fuel contamination or water build up in both tanks is likely to result in one engine failing a few seconds before the other. So I can't come up with anything other than both fuel cutoff switches that would result in loss of thrust and RAT deployment. Looking at a picture of the cutoff switches https://www.nycaviation.com/2013/08/...is-fired/30179 I don't see how they get hit by accident.

I'm confused, hope we get an FDR / CVR readout soon.

Here's another YouTube presentation.

Similar to the Emirates crash following the attempted go around in DXB, momentum can be converted into altitude until speed runs out and gravity takes over.

On the Airbus, if we take off in anything other than 1+F, I'm watching the F/Os left hand very carefully when I call for flap retraction.

If it was inadvertant flap retraction then they would have lived had it been an Airbus ( alpha floor prot, slats don't retract etc)

My 2 cents: this accident will be a catalytic event.

It will soon come to light pilots crashed a 100% working aircraft. Boeing and Airbus will present a near automatic airplane as a consequence very soon.

This accident will be the gravestone for the handling ( and thinking) pilot.

I\x92ll reply to my own post in light of the RAT deployment. If true then this opens up to a lot more. And simply guessing with grainy video a fools game. All I saw was gear down to high Into the climb. This should not happen under any circumstance . Dual engine failure would explain the loss of lift obviously. Early flap retraction also. One would hope it\x92s not a simple as that: cheers

I think it\x92s normal for most, even those with time on type, to point to the flap or gear lever issue. It was the same with the MAX until all the software issues came to light, the software was not really something top of mind, these machines are built and designed with precision, the thought of software causing havoc is somewhat implausible.

I think the discussion is at a standstill until we get more clarity on the flap position, and the RAT. The latter will become an issue for Boeing if that was extended, and they will need to work around the clock to prevent future mishaps, and reassure many flight op departments, especially those with early build 787s, that this is a isolated event.

I tend to agree. I taught ground school for the 744, 748, 777, 320 and 330. I used to tell my students the most critical phase of flight is the 3 minutes after 100 knots. That\x92s when critical TO inhibits occur and ADP\x92s (777) come online etc etc. But the elephant in the room for me is thrust reduction. On the Boeing it can be an altitude or a flap setting where the AT will reduce thrust from derated TO to CLB. For the Bus it\x92s an altitude and the crew are prompted to move the TL\x92s to the CLB detent. If at positive rate (or climb) the PM selected one or two units of flap up instead of gear up would the thrust reduction explain the aircraft\x92s response? This would startle any PF and he wouldn\x92t (muscle memory) manually move the levers back to TOGA while trying to follow the FD Bars to maintain V2 and RWY heading.

If the RAT deployment is indeed confirmed then my theory is out the window\x85.

There isn't enough clarity on numerous issues, and without answers to the following, zero conclusions can be made as to a possible cause. This is definitely one that could go in numerous directions. Anyone claiming to have the definitive answers must have the FDR data, and I'm assuming that shouldn't take too long to be located and analysed.

1a. Were flaps deployed at start of take off roll?
1b. Were flaps retracted coinciding with climb rate reduction?
2. Did the RAT definitely deploy? The videos are grainy low quality. AI improvement surely isn't reliable.
3. If the RAT deployed, would that indicate complete power loss?
4. Was there any other audio indicating thrust loss or variations during departure?
5. Can we confirm the pilot Mayday indicating thrust loss? If so, that needs investigation as a first priority. The pilot was telling us the cause. Unless we have alternative information he should be believed.
6. Why was the gear not retracted? Distraction, hydraulic failure, flap instead of gear, intentionally, the possibilities are endless.
7. If complete thrust loss occurred, other than a severe fuel issue, what could cause simultaneous flameout? That would be almost unimaginable, yet this is what the pilot allergy said happened. It would have massive ramifications if that gets confirmed.

I don't think the video clips we have are clear enough to say anything at all at this stage. Flaps are hard to see on 787 imo for departure settings. All I can say is it appeared to climb well in the first seconds, then coinciding with the point that gear would usually be retracted, lift appears to very quickly be lost. That indicates sudden speed loss, or lift loss. Speed loss would be thrust, lift loss would be flap retraction if thrust was still available.

The pilot allegedly reported thrust loss, that should be highest on the list of causes imo. In the case of double engine failure without any apparent outside influence visible on videos, that would be quite something for investigators to fathom.

I don't know if anyone has data to show speed trend at the point the aircraft starts to descend, or a better audio for thrust variations at that point. I'm guessing that the update frequency on FR24 would be too slow to show that sudden change at the highest point achieved.

We'll have the answers soon enough, all I can say is there appears to be no clear answers here without the data recorders or clear improved information. Indeed no conclusions whatsoever can be made as to crew actions either.

RIP crew and passengers, condolences to the families.

FR24 data appears to stop shortly after airborne but well before impact.
That would seem to align with the significant loss of electrics as a result of loss of engine generators theory?
Flaps prematurely retracted shouldn\x92t be a cause of loss of electrical power to the transponder. If electrical power was normal then one would have expected data info until impact, regardless of flap position.

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.

Most likely anything between 256 and 1024wps, individual parameters will vary with regards sample rate. Not au-fait with 787 but other Boeing aircraft may have dataframes relative to the original owner requirements (though this is unlikely to vary much given my experience with Boeing aircraft). I\x92m not sure if GE have a real time EHM feed like RR? Anyhow, and not wanting to speculate too much, if there was anything engine related it would certainly show up on the DFDR and GE could possibly even know that by now if they are equipped with real time health monitoring. In my opinion, for what it\x92s worth, the CCTV footage is consistent with flap retraction instead of gear, something that would also be easily identifiable upon review of the FDR which will be reported upon in due course.

Totally agreed. But at some point with the buildings coming into 8k definition, one would hope that a pilot experienced enough to be employed on a 787 would disconnect everything, firewall it and pull up the nose..

No, these jets are designed to fly on one engine after takeoff. With two running, a flap retraction and then extension wouldn't be an issue.

Firstly, I don\x92t think an inadvertent selection of flaps up caused this accident. I think it\x92s a red herring that seemed plausible initially but it is not consistent with the RAT being deployed, and the evidence for the RAT is strong.

To answer your broader question though, how could such an error happen? It happens because us simple humans learn how to do actions to the point where we don\x92t have to think about them anymore. This allows us to effectively automate routine tasks and save our brains for more novel tasks. The problem arises when we trigger the wrong automatic action in response to a cue. You ask for gear up, I know I need to select the gear up, I know where the gear handle is and what it looks and feels like, yet something goes wrong in the wiring of my body and instead, the flap-up automatic action is run. It\x92s run before I have consciously thought about it.

Sound far fetched? Well it has happened numerous times. I\x92ve seen someone do exactly that, select the flap instead of the gear, and there are incident reports publicly available. All modern passenger jets have a similar layout of the flap lever and the gear lever with the gear looking like a wheel and the flap looking like a wing, yet this error can still happen.

Have you ever gone to put something in the fridge that should\x92ve been put in the cupboard? I\x92d bet that most people have made that weird error at some point in their lives, and yet the fridge doesn\x92t look like the cupboard and they\x92re nowhere near each other.

Having experience of many crash sites over a long career, taking off without flaps with the config horn/ warning blaring (or not if u/s) is a possibility Also selecting flaps up, instead of gear up at the positive rate of climb call, is also not unheard of and has happened. Both engines failing/ losing power at rotation/ initial climb out would be extremely rare, but not impossible. With the descent and lack of climb clear, unless a mistake of retracting flaps instead of gear, why wasn't the gear selected up as dragging that around is only going to end one way.
he sound from the well documented video would suggest the engines were running, but were certainly not selected to TOGA/ full power which you might expect when faced with high buildings growing larger in the windshield.
Due to the tail section being relatively intact, the CVR/ DFDR will be downloaded very soon, if not already, so we will all know shortly....

I think flap setting for takeoff is not in the equation because the aircraft became airborne and was seen in the video climbing away, the takeoff is over.
retracting the flap instead of the gear is a high possibility, yes there would be sink but the aircraft would still be accelerating, distance over time says an impact speed of about 120 kts.
where it would have been 200 kts in this scenario. I also think it would be unmistakeable to those on the ground if the engines were at go around thrust at impact.