BREAKING NEWS: airliner missing within Egyptian FIR

[lomapaseo]

Engines

Prada

It is most probable that the engine got damaged in the falling phase, still attached and working by ingesting flames from fire.
Left side of the forward fuselage have marks of inflight fire and sooting up to the nose cone.

Agree

Sooting likiely associated with a free fall in flames while still attached to wing and later separated due to spin/spiral side loadings.

I believe the other engine which also shows up in the news videos is quite similar in completeness and ground impact damage.

Nothing of major interest except the suggestion of fire forward of the wing while the engine was still attached.

Incidently, I've never heard of a tail separation causing a fuselage break forward of a wing box but we'll see what turns out in this report as all will be revealed eventually.

[A0283]

Still missing update 8

Another set of pictures that i am still looking for is a better top down view of the main impact site. From the cockpit section to the wing.

When you look at the available images it COULD look like roughly three section segments that lie in a zig zag, one segment behind the other, between cockpit and wing.
You may have expected a denser debris field. But we dont know how long there was a fire and what rescuers had to do to put out the fire and recover the passengers.

When you estimate the distance between wing and cockpit, and then would add distance because of the possible zigzag ... what do you get? Has anyone measured either one of those two distances?

The max total length that i expect would run from behind the front pax door to a number of frames before the third pax door.

Early on i wondered whether the whole fuselage was visible. But the clear section segment around the third pax door rejects that. Which means that my impression is that we are still missing the aft cargo hold as described in update 7.

[triumph61]

Here is a little collection of Pics. Look at Sections Door 2L and 2R

https://drive.google.com/folderview?...2M&usp=sharing

[PersonFromPorlock]

I may have missed the crash where PPRuNe armchair experts got there first, but I don't remember one.....

Fair comment, but recall that the CBS/Dan Rather/Memogate scandal was uncovered by 'armchair' experts on the web who observed that the 'typewritten' 'official documents' presented in evidence were produced on a computer using software that wouldn't exist for another twenty years. So on occasion amateurs can help, and probably don't do much harm the rest of the time.

[Kulverstukas]

Taking pprune in general, I can confirm that at least RedWing overrun was solved in two Russian aviation enthusiast forums (aviaforum and forumavia ru) way earlier than any official documents was released. So was Kazan crash if not so fast and sure.

PS: way more interesting, in RW case field test was carried out with one tech guy, coordinated by forum posts

[CONSO]

CVR and FDR questions

I note that the CVR and FDR were recovered almost immediately

Location as installed - can be shown at

http://www.pprune.org/rumours-news/5...ml#post9169622
4th Nov 2015, 22:38 #996 (permalink)


I note that CVR shown at

http://www.pprune.org/9168948-post878.html
4th Nov 2015, 16:23 #878 (permalink) CVR has been removed from area attached to skin of tail cone near jackscrew


I note that other recorder is somewhat bent --- FDR - ? but removed or torn from tray ??

http://www.pprune.org/rumours-news/5...ml#post9165152

++++

OK- None show fire damage and all told are quite clean- rules out fire IN that compartment- sort of expected

But the generally good condition absent dirt of the CVR and the traces of dirt on the FDR - to me indicate the CVR was on or in the section including the jackscrew- maybe the HS wingbox, etc. A pair of bolt cutters could easily have been used to remove the CVR as shown by the attached framework ( either bent or cut and folded over to avoid sharp edges when handling. One was removed from tray before photo.

IF --big IF the CVR was cut from the framework or twisted off- then the part(s) missing from released photos and press etc were removed before press got to area.

Those **may** be the parts that define the problem which may not be shown until investigation is well along- IF our recent speculations are close- that it is a maintenance issue OR a well placed small explosive ---

[andrasz]

I may have missed the crash where PPRuNe armchair experts got there first, but I don't remember one.....

I do recall that the discussion following PAF101 have settled on essentially the same conclusions within 2-3 days as were confirmed by the accident report a year later, to a large extent attributable to the accurate factual information supplied by one forum member going by the name of Kulverstukas.

[A0283]

I may have missed the crash where PPRuNe armchair experts got there first, but I don't remember one.....

It's not a game.

The main goal for accident investigation is learning lessons and thereby preventing future accidents. I would say that people on Pprune are more interested in learning these lessons than the average person.

There are many ways to look at an investigation. One for example:
a. input,
b. access,
c. processing,
d. output,
e. learning lessons,

In the input stage you usually have a number of people who know little or nothing about aircraft. Some are called witnesses. A person taking a photo of this plane just before takeoff - even if knowing nothing - is a valuable witness who provides input. Spotter's pictures are now routinely used. So even laymen can be first.
During the MH17 investigation some people offered assistance. This was rejected. Lateron the investigation asked people if they could help to provide more pictures and information. A proper investigation knows how to collect and integrate ALL information. The crowd has the advantage of numbers. This investigation has 47+11=58 persons. When you want to find a certain (input) video or photo ... and ask the investigators or pprune members ... who would find it first ... you might be surprised.

Investigators will have and should have access to all ('available') information. And they decide what is shared. So people outside the investigation have less access.

Processing is related to experience. If you compare an investigator with 1 year of experience to a person who has just retired after 40 years in the business ... who would you listen to ... I would listen to both.

Output is that of the investigation. Simple. But we all know that there can be a lot of discussion ... going on for many years ... Some extra knowledge is an advantage when you want to make up your own mind. And that brings us back to learning lessons.

A few days ago a person posted that all people visiting this site were 'idiots'. So he joined up to tell other people they were idiots visiting this forum. He gave a new meaning to the word "irony".

[Bertie Bonkers]

@CONSO

Is that not the cvr the chap in hi-vis is holding? Sat on the bottom tray as best I can figure from Kulverstuka's photo. Back end bent down by something large & very close behind it hitting it hard?

[Mr Optimistic]

Once the tail had departed, is it clear where the loads would come from to split the fuselage at the wing box ? The inertia of the rear fuselage may not be sufficient. If so the tail must still have been attached at that point generating a force and moment opposing the wing lift, if so the tail separation was later. Ditto the HS, is the inertia of the tail alone sufficient to allow shearing by aero forces ? If not they must also have separated when the tail was still attached to the larger body.

Hardly seems necessary to point out that this is speculation......

[RYFQB]

Originally Posted by Ian W

It was recorded the thin trace - then someone 'computed' a different trajectory smoothing where changes were not thought realistic.

Yes and no; let me explain what was done and why:

1) The thin trace is recorded pressure altitude, and yes, I didn't think it looked realistic.
2) What I did wasn't smoothing; I first took recorded vertical speeds prior to upset and used those to calculate altitudes (starting at 28000 feet). The calculated altitudes matched recorded altitudes to within a few tens of feet - prior to upset.
3) Considering that a success, I did the same from upset onwards. Now the calculated altitudes did not match recorded altitudes, and the new plot is, yes, surprisingly smooth.

The first problem with the recorded barometric altitudes post upset is that they bear no relation to the recorded vertical speeds. That "zoom climb" for instance takes place while VS is (very) negative.

Secondly, the altitude changes over time for the first "climb" works out to a VS of 95280 fpm or 488 m/s, followed by a descent at -187800 fpm or -955 m/s (M3.15). If the transition was linear, the plane pulled -42G there. And something similar happened another nine times over the next twenty seconds.

That's just not believable, is it? I'm just some random dude on the internet though, so if you don't think my calculations can be trusted either, that's fine.

[fyrefli]

Originally Posted by lomapaseo

Sooting likiely associated with a free fall in flames while still attached to wing and later separated due to spin/spiral side loadings.

I believe the other engine which also shows up in the news videos is quite similar in completeness and ground impact damage.

Nothing of major interest except the suggestion of fire forward of the wing while the engine was still attached.

Incidently, I've never heard of a tail separation causing a fuselage break forward of a wing box but we'll see what turns out in this report as all will be revealed eventually.

You're not the first to make this observation (although you've made it in more detail than others). I've pondered whether it's possible for the aircraft to have entered such an attitude that the flames were behind the engines (behind in the sense of the usual direction of travel) but in a state or transition such that they ended up in front of the flames in the airflow.

Please excuse the question if it's daft - the aircraft I fly are two-axis, engine-less and their stability owes itself largely to me hanging under them!

[RYFQB]

Originally Posted by lomapaseo

Nothing of major interest except the suggestion of fire forward of the wing while the engine was still attached.

This might be incredibly stupid, but if the aircraft was in a flat spin, could one engine be moving backwards and ingest flames from a fire behind it?
Edit: fyrefli asked basically the same thing in the previous post. And here's that iranian IL-76 posted by rcsa earlier.

[Lonewolf_50]

Originally Posted by RYFQB

This might be incredibly stupid, but if the aircraft was in a flat spin, could one engine be moving backwards and ingest flames from a fire behind it?

My first instinct on that thought it "but it's also falling, so what we might think would be ingested is above it" if that makes sense. The plane falls, even in a flat spin, because a spin is a subset of a stall, and once stalled, the plane falls.

[A0283]

@RYFQB

If you take recent accidents as an example you would expect fpm in the range of 6,000 to 13,000 fpm. With 9,000-10,000 fpm as the more likely ones.

In this case the vertical speed appears (just my first impression, no more) to have been less than in the AirAsia case. But without having any specific data you could start with a 9,500 fpm estimate.

When you look at the numbers and go over 20,000 fpm and even an order of magnitude higher ... then you know that it is highly unlikely that these numbers are correct.

Try to find a solution ... that's what random dudes do ...

[Kulverstukas]

Bertie Bonkers
@CONSO

Is that not the cvr the chap in hi-vis is holding?

CVR has square memory housing and FDR has round one (if photos in press reports are correct).

[HundredPercentPlease]

Also why the 'double line' scrapes to this segment? I have not seen those before. (The two sets of parallel lines on the VS going horizontally)

Intriguing. I have put the broken part back in position, but they still make little sense.

[Barry Plumb]

Engines

Thanks to Triumph61 and A0238 for further pictures and details of the engines. you are correct, the only piece missing from the front of the left engine is the fan, which is located close by.
Looking into the front of the cowling, I guess that is the front of the compressor section we can see. The by-pass duct is very sooty.

[Yankee Whisky]

QUOTE: Free Flapping HS I don't want to get involved in this, but just thought I'd point out one thing if I might. If the HS is ever free to move about it's pivot point (ie sans jackscrew) it will align itself with the oncoming air (weathervaning), not slam to one or the other stop. It's takes the path of least resisitence.
END QUOTE




I think the writer of the above must bear in mind that the horizontal control surfaces consist (normally) of three parts;


a) the stabilizer which leading edge is moved by a jackscrew
b) the elevator which is operated from input by cockpit controls and
c) The trim tab which is used to trim the aircraft for hands off (auto pilot) flying. (or a combination of b) and c) where the trim tab does all the work to move the elevator)


Now visualise the jack disconnecting from the stabilizer. Would the airflow then not move the stabilizer either nose up or down depending on the starting position ? Yes, the elevator, if disconnected would free float and take a position in the flow influenced by the trim tab position.

[Bertie Bonkers]

Originally Posted by andrasz

@ Bertie


As the HS moves down, the aircraft nose pitches up, and this would be recorded on the FDR prior to loss of sgnal. As the FDR loss of signal was abrupt without anything but normal parameters, the tail separation had to be one of the first events.

I'm thinking in terms of a sudden violent event - such that the inertia to be overcome in pitching the nose up would create enormous tension at the top of the cabin.

In terms of the flight recorders, I may be pushing the plausibility envelope, but I see some possibility that their connections were destroyed by the sudden movement of the HS internal structure beyond its normal operating limit.