> I'm just reciting what's been shown in videos

Of unknown provenance, with unknown visual artefacts, et cetera. Even if completely legit, with context and thus chain of causation obscured to the point that discerning ultimate and proximate causes is impossible.

Some people trust their own thinking to judge what they see.

We know it called mayday and then lost communication. It also stopped transmitting GPS data.

Looking at this it likely lost all electric power. The electric power comes from generators driven by the turbines.

If you lose both turbines you lose electricity. You also lose the hydraulic system so you can not get in the gear or change flaps.

Occam's razor checks out.

Don’t these Dreamliners also have back batteries?

Even on light GA aircraft the radio will run for an hour on the starter battery. This narrative doesn't sound realistic.

Yes and many pilots being walkie talkies in GA as backup. Not sure if airline pilots do this though. And its kinda hard to root around for it and fiddle with it while trying to keep an unpowered jetliner in the air. They're more for emergencies where the radio is the only problem.

By the way, the age old rule is "Aviate, Navigate, Communicate" in that order of priority. So it could be they just had their hands full with the Aviate part.

They have a RAT (ram air turbine) that deploys automatically under specific conditions. It’s basically a turbine providing electric and hydraulic power. It was almost certainly deployed on the accident flight. It will only power the most critical equipment, though. Possibly, that does not include the ADS-B transmitter (which broadcasts position and related data).

This analysis is convincing about being able to hear the sound of the RAT from the crash video: https://www.youtube.com/watch?v=SbDJjgN7Xbo

Yes, lithium ones, those were the ones that kept catching fire then the 787 was just out.

I guess they're just for the time until the RAT kicks in. Or to augment it.

Ps there's also the APU, a small turbine in the tail for generating electricity.

Agreed, but it doesn't look like AI. Video(s) look real to my untrained eyes. Everyone is going to speculate regardless of the top level disclaimer. I rather just at least present what data is available as of now.

The city the incident took place in has a subreddit. Feel free to go take a look and judge for yourself. It's a bit NSFW at the moment.

> present what data is available

It’s not. It’s one video of unknown quality and relevance, picked somewhat randomly out of all the other available videos and data, the most relevant of which aren’t publicly available.

> Feel free to go take a look and judge for yourself

It’s the usual emotional coping through baseless speculation. There are healthier ways to deal with uncertainty amidst tragedy.

I wish every news was held to this standard.

The industry would be substantially smaller. This runs counter to the interested of every existing industry participant.

I agree. Not sure if there's any possible alternative worlds where the checks and balances shake out something better either sadly.

Both slats and flaps were on maximum during the entire flight.

That makes no sense, and is not consistent with video evidence. Max flaps (40 degrees or so) are typically used only for landing. That is very obvious when you see it! Usual flap setting for takeoff is on the order of 5–15 degrees.

Well, loss of engine power and gliding to a stop is not that a far fetched case. Why is there not a fuel dump button to prevent a whole trips worth of fuel going up in flames?

There is, but dumping takes time, and it’s not done over populated areas. It would be low on the pilots’ checklist in an emergency.

Yes and smaller airliners don't have it. As I understand it, it's for the widebodies because they often have a higher maximum takeoff weight than maximum landing weight. Meaning that if they just took off and need to return right away they have a big problem. Because they're too heavy to land.

Most airplanes can dump fuel, but it's not an immediate thing, so not really applicable here (and obviously doing it over a city is to be avoided as well).

It's primarily needed for weight management in planes that can take off heavier than they can safely land. I.e. if the plane had enough control to abort the flight and return to the airport, then it might have been appropriate.

No. Most airliners CANNOT dump fuel. This capability is limited to long range wide bodies, like this 787. Neither the 737 nor the A320, which constitute the majority of commercial air traffic, can dump fuel. Fuel dumping is normally performed at an altitude where it should be able to evaporate before hitting the ground, and it takes a long time, maybe 15 minutes to get from full fuel to maximum landing weight. Using it would have made no difference to the outcome of the flight other than making a larger fire on the ground.

A more dispersed fire. The amount of fuel isn't changed by dumping.

No. I said a larger fire, and I meant it. The fuel on the aircraft is not the only thing feeding the post-crash fire. Dousing the entire flight path with an accelerant would have resulted in many many buildings being on fire, instead of just a few of them.

Didn't Sully dump fuel before landing in the Hudson, thereby increasing the buoyancy of the plane?

No, the Airbus A320 cannot dump fuel.

They were only 600ft in the air, barely anything would have got out before they hit the ground and you'd have just set non-zero amount of innocent people on fire in all likelihood when the crash ignited the trail they'd left.

There is a dump fuel button if you're not in the middle of a populated city and you're far enough in the sky you've got a few minutes.

because painting an entire neighborhood in flammable fluid isn't safe... if it doesn't catch fire it'll corrode everything it touches.

most planes can't dump fuel anymore. if it's a serious enough emergency you land overweight. If it's not then you fly long enough to burn it off and land below max landing weight.

> most planes can't dump fuel anymore. if it's a serious enough emergency you land overweight.

When fuel is dumped, it's at high altitude where it just evaporates.

Short haul jets can't do it, but their max takeoff weight is around their max landing weight, so it's fine. For long haul, it's not the same.

Are both opposing replies just wild speculation from two educated software engineers that don't actually know anything on the topic?

No one overestimates themselves in other knowledge domains quite like software engineers... with the possible exception of medical doctors.

> most planes can't dump fuel anymore

This is true but irrelevant to this crash. Most commercial jets are smaller (A320, 737 etc) and can't dump fuel.

Long-haul jets like the 787 do have the capability.

https://www.boeing.com/content/dam/boeing/boeingdotcom/comme...

If it’s HN, yes always.

This airplane was not at high altitude. It crashed right after taking off. It only ever climbed to a few hundred feet in the air.

Yes, I was refuting the generic "planes don't dump fuel" statement.

It wouldn't have been in this case, is the point people are making.

It won't corrode I don't think. It's just oil, it's not petrol like in small airplanes.

It's possible to dump fuel but you don't have time to dump enough in an emergency

Do you have a source for this footage or are you referring to the video everyone is recirculating?

Do you have a link to that footage? I've seen speculation on this from very blurry video but nothing like proof.

On the professional pilot forums the consensus guess is inadvertent flap retraction, instead of gear retraction, leading to inability to climb.

A 787 can still climb with flaps up and two healthy engines. In the video that was posted everywhere, you can CLEARLY hear the RAT spin, which gets deployed automatically when both engines go out.

> A 787 can still climb with flaps up and two healthy engines

Not at takeoff weight with the gear down, this sentence is incorrect.

Reddit link - https://old.reddit.com/r/interestingasfuck/comments/1l9no7u/...

Or birds hitting both engines. But that must have been a big flock then

It's unlikely that a bird strike with dual engine failure would occur without smoke.