In post 120, the discoloration is what nearly molten aluminium looks like.
Per

What, and it's taken the whole day for them to find this... yeah, right...Social Media is not a medium to be trusted...
However, as our early Posters will revel in the fact - the pebbles/ stones are the same size as the fragmentation holes on the airframe. We must bear in mind that the whole f'ing World is dumbing down to this sh1T.

Post this image? - I want proof it's taken from the same location as the crash site or it's negligible.
Can you provide a source please, credible and checkable.

Boeing recently said it was revamping engine cowlings on the Neo to better contain engine failures. This comes as a result of NTSB recommendations after the fatal accident on Southwest Airlines about a year ago when an engine fan blade broke off in flight, punctured a cabin window and sucked a passenger partially out the window, causing the first US passenger fatality in more than a decade. Does it seem unreasonable to think that such a failure, or worse, could puncture the wing and fuel tank resulting in something like this crash? The NTSB also recommended regular inspections of the fan blades in the CFM engines used on this aircraft type. I wonder if Ukraine Airline is doing these inspections.

Possible scenario:

1. Uncontained engine failure of the right engine (e.g. turbine disc, similar to QF 32). Unlikely for a CFM 56 engine but not impossible.
2. Shrapnel from the engine failure damages airframe, tanks, systems, hydraulics and takes out radio, transponder and electronics.
3. Massive fuel leak (similar to QF32)
4. Hydraulic failures make A/C control difficult, therefore wide, descending right turn
5. Aircraft on fire due to fuel leaks
6. Explosion of damaged fuel tank while the plane descends. Explains further, shrapnel like damage.

The root cause is unlikely for the CFM 56 but not impossible.

The rest is easily possible taking into account the massive damage to the A380 on flight QF32. A little less redundancy (and the A380 has got a lot redundancy compared to a 737) and they would have crashed as well.

The exhaust duct is titanium and corrosion resisting steel not aluminium

1. After the missile exploded the search head will be gone. Destroyed, evaporated, whatever.
2. The search head would be found where the missile hit - many miles away (if it was a missile) and not at the crash site.

It’s 2 that seems a real long shot....?

​​​​There are multiple examples of the same missile type leaving the head intact after the missile explodes, posted in that Twitter thread.

I think it would be wise to avoid making extremely general statements about munitions/weapons that we're not familiar with.

The Search Head would be utterly destroyed; by it's own munitions dispersal pattern. I think this is a Search Head from one of the undetonated rockets that failed on the earlier rocket strikes on USA bases. Nothing to do with the aircraft accident.

Social Media at it's best - worst.

Yes. The chances that the seeker would survive warhead detonation in such good shape don't seem very high. And it shouldn't be anywhere near the crash site.

The social media post and the photos are unconvincing.

Have you got a source for that exact wording, because as far as I know the cowling will never be able to contain an errant blade, only the fan casing will? Moreover,

- the fan appears to me to be too far forward to be able to puncture a wing tank;
- the AD's regarding fan blade attachment on the CFM56 engines have been around for so long that there should be a great deal of awareness around about this issue, to the extent that this shouldn't be an issue anymore;
- the two Southwest aircraft which had uncontained engine failures were 10-15 years old, and the present aircraft is only about 3 years old;
- from a statistical point of view since several years there is a huge amount of B737's with these engines around, logging a tremendous amount of flying hours, yet such a catastrophic engine failure has never happened....

A SAM missile search head from a rocket strike? :confused:

What would happen if a pickle fork failed during climb out? Could this result in something similar?

I have my doubts about the relevance of that photo to that incident too, but this notwithstanding

- regarding point 1, how did that (charred) seeker head then end up on the ground in this state?
- regarding point 2, nobody has claimed that if was photographed at the crash site....

Well the pictured head is certainly consistent with a TOR -M1 missile and is not from a ballistic missile (too small). There is no reason why the seeker head of the missile would be distroyed in the detonation. It is ahead of the charge and from the photo has a fairly substantial looking domed structure at the rear. It is surprising what close to the charge will survive a detonation. Lots of forensics from detonations have led to convictions in the past. I have personally seen an optical seeker head thar survived detonation remarkably well.

In that case, disregard as I have no experience welding titanium and overheated steel does not look like that.
Per

Boeing Neo??/ Ehmmm you mean MAX.

100% sure UIA did those inspections.

Observations:

The only 'outward peeling' apparent to me (closest to camera) coincides with a score mark that lines up with the tear in the metal - when i first saw this it looked like something scraped along the surface and ripped the metal up... especially as the 'score' stops at the point the metal would have been if it was still flat against the engine...

Also how does an uncontained engine failure result in debris creating inward facing holes? It is possible these were inflicted on impact, but the same could be said for the tearing mentioned above.

Additionally, an uncontained engine failure could have been the result of external action - so you would have evidence of both outward in and inward out.

9M331 missile heads look like that after explosion of the charge below them. Pictures can be found on the internet from combat use e.g. recently in Syria.
But agreed, no evidence is there to show a link in time and location to the Tehran crash site. The picture could be from anywhere and anytime.

Using a few aerial photos from your link and Google Maps' 'Measure distance' feature, I found the debris field to be 330 metres (1,080 feet). I don't have forum rights to post my screenshot. :(

I tend to disagree
TOR | Lugansk News Today
http://lugansk-news.com/wp-content/uploads/2016/02/InRussia.jpg

Here is an example
TOR SAM | Lugansk News Today


https://cimg0.ibsrv.net/gimg/pprune....c1ac2a5ac3.jpg

The warhead on the missile is designed to cause an annular blast throwing its folded continuous rod outwards, the explosive force travelling axially towards the seeker head will be significantly reduced. The bolted structure of the seeker is pretty strong, it would not be damaged easily.

Other photos taken near the crash site show an area with 2 parallel low concrete walls quite close together, it is possible that the seeker could have lodged in the airframe and then fallen out during the ground impact sequence.

This is a statement of possibility, like everyone else here I have no magical insight.

I would have thought given the acrimony between Iran and the US at the minute that all sorts of surveillance data would available to the US that would have quickly indicated a rocket/missile launch in Iran. Even a quick event such as this would not have gone unnoticed I would have thought thus, unless the US is sitting on it's hands (data), they would quickly have confirmed or discounted the missile theory.

OK, I'll bow to superior knowledge, although it's certainly counter-intuitive that the seeker head would be so well preserved after detonation of the warhead and falling from, what 4-5K' AGL here?

Corrected that for you.

Ah, no, he's thinking the 737NG, which is what this thread is about.
That being said, the chance there is any connection between this crash and the Southwest fan blade issue is close to zero.

It's virtually certain that both the US and Iran have comprehensive radar coverage of the relevant airspace and the US will also have satellite imagery. Others may, as well. It seems extremely unlikely that a missile track would not have been recorded somewhere.

I might be wrong..(gosh, we could all be) but I think the design of these munitions is like shaped charge ie that are very directional. This particular missile system is for killing small fast maneuvering targets (read other rockets) in a defense role. As such it is unlikely to ever be able to actually hit the target directly. It would rely on proximity fusing and a concentrated fragmentation field that is designed to kill a target it may be flying past (crossing paths with) rather than one directly ahead of it. So yeah, the head may have simply been separated at time of charge ignition without actually being hit by the charge. All spec of course but the image gives some clues. 1. the seek head has been separated from the charge without being destroyed by the charge. 2.The seek head appears to have suffered little impact damage suggesting it wasn't attached to the missile body when it hit hit ground.

The assumptions from this seem to suggest this particular round wasn't a dud ie the charge ignited and that since it is a missile defense system, it is not a ballistic missile and is therefore very unlikely to be an image from 'dud' rockets launched by Iran on American bases in Baghdad.

So this seeker head had a starring role in something. But until we can determine where and when it was found, there remains no connection to this 'accident'.

If it was an uncontained engine failure, the high energy debris will remain with +/- 5 degrees of the plane of rotation. Any engine debris outside that arc would have insufficient energy to penetrate the aluminum structure, so any shrapnel holes outside that arc didn't come from the engine.

The US appear to be willing to let things die down - hence Trump's "standing down" remark. If they have evidence it was a rocket/missile then saying so now could re-ignite the tension. The evidence could still come out in due course as the investigation progresses.

If it wasn't a rocket/missile then the US have nothing to gain by saying so at the moment. The truth will come out in the investigation, but in the meantime there is no harm to the US position of leaving the cause of the crash as an open question, especially whilst there is speculation of an Iranian own goal.

And possibly the US wouldn't want to reveal exactly what their capabilites are at the moment when it relates to looking at things going on inside Iran.

Agree. All sorts of contradictory statements being made by Iran and Ukraine, social media all over the place, phony attacks on US air bases where it seems missiles were deliberately targeted onto vacant areas of the airfields to avoid casualties, and no doubt a US surveillance system in overdrive that would have spotted a mouse running for cover and would certainly know the whereabouts of any missile system launchers and command modules and if they had been fired.

We may not be in a hot war, but the only thing we can be sure of is that old adage:

"Truth is the first casualty of war".

Agree, the term "explosion" was imprecise. What you have described is exactly what I was thinking including the example you used: fire-weakened structural failing under load, likely a wing spilling its load of fuel.

PJ2

You can understand that due to the sheer volume of 737 flights worldwide on a daily basis, this devastating crash of a 3 year old airframe in a part of the world that has seen an unprecedented amount of alarming activity in recent days is being regarded by some as slightly more than coincidental.

Both of the recent accident aircraft (SW1380 & SWA3472) had high energy debris outside of that arc I believe. Hence the work being carried out on CFM56-7 engines.

Wether that’s relevant to this accident, I don’t know. Happy to be corrected.

I would expect an engine failure (uncontained or other) would be a natural result of the aircraft being hit with a fragmentation warhead...some of the frag is certain to destroy the engine. It seems plausible that you'd see both frag damage and uncontained engine failure damage.

MH17 damage report
 

There is a comprehensive report for the MH17 shootdown that explains the consequences of a SAM strike.

https://www.onderzoeksraad.nl/en/med...pendix_nlr.pdf

Sorry gents, but the video posted everywhere showing the last 30 seconds of this tragic flight shows everything but an engine fire. The all thing is a fireball breaking up several times before final impact.

I can tell you that is incorrect the search head would be destroyed. That’s not the way missile warheads function. They are designed to throw out a expanding cone of fragments almost like a big net. They blow straight out from the missile not forward, I would expect the guidance section to survive.
I would not however expect to find the guidance section with the wreckage unless it got embedded with the aircraft.

I agree. If you've ever seen compressor stalls at night, they can make the engine look like it is in afterburner. :eek:

I can see where the gap between the last ADS-B position and the debris field implies a possible right turn back toward the field. But this may have been after an initial explosion as the plane fluttered down out of control in flames. Kinda like the story that has already run about how 'the pilot' avoided the madrassa and crashed the plane into a soccer field instead.

A journalist from an opposition party media operation claims to have verified the turn back to the field through his online forensics:

https://cimg3.ibsrv.net/gimg/pprune....10fca03722.jpg
https://cimg4.ibsrv.net/gimg/pprune....665915f9f0.jpg