How many times has a jet airline flight suffered a major structural failure not caused by an explosive weapon, which disabled it so suddenly that the flight crew never sent a subsequent radio message?
I haven't yet thought of an example. Anybody?

plenty post 1970
how about
China 747
adam air 737
Egyptair 990
Lauda Air 767
Air Asia A320
Gol 737

plus plenty of crashes such as Gulf air Armenia and XL A320's Birgenair 757
and Flash KQ and ET 737's that did not transmit

all where the crews did not manage any distress call

I would put a distress call at the last of my priorities if it would not help in any way. I think most pilots feel the same. Save the ship, if possible, then when you find time deal with the communicating. Aviate, Navigate, Communicate.

@rog747:

Thanks for posting the list!

The China Air Flight 611 crash is a genuine precedent for the Metrojet crash -- if the disaster in the Sinai proves to have resulted from a spontaneous structural failure, and not a bomb. I had not remembered, that the China Air flight made no distress call.
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Indeed, Gol Flight 1907 did suffer a major structural failure at altitude ... after colliding with another jet. I wasn't thinking about that case, and should have specified without external cause. There seems to be no evidence that a collision contributed to the demise of the Metrojet flight.

Of course, we have other examples of structural failure at altitude downing airliners too abruptly for a distress call, where the cause of the failure was external to the aircraft. Even Kremlin fantasists seem to concede that MH17 was destroyed by a missile.

Considering the other accidents in the list:

Adam Air Flight 574, Lauda Air Flight 004, and Air Asia Flight 8501 all suffered major structural failures, but none at high altitude. Like Gol Flight 1907, they all appear to have been broken apart by aerodynamic forces during uncontrolled descent, following a gross upset -- none of them involved structural breakage above FL300.

Egypt Air Flight 990, famously attributed to murder by a flight crew member, had no structural failure at altitude.
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I didn't check all of the other no-distress-call crashes listed, but they seem to be accidents that occurred in approach to landing or soon after takeoff. In conditions of high workload and close proximity to the ground, the absence of radio calls seems natural and expected.

Someone has said it may have been contained in a 330 ml fiz can. This should not weigh more than 300 gm. Would a little tin of fizz weighing in at 1 kg been rather odd. Add to this a trigger/detonator/timer for it to go fizz bang boom, the little can would need to have all the internal dimensions of Tardis.

Alleged bomb estimated at 1kg.

For comparison, an estimated 340g-450g of plastic explosive tore PA103 in half in under 3 seconds.

No, alleged bomb estimated as having a yield equivalent to up to 1kg of TNT. That could well end up being smaller than the Lockerbie device.

Respectfully asking -
Have they identified the type of explosive?
And
Is the suspected location sufficient to immediately sever the lines to FDR?

Lastly,
Can we imagine a "non-bomb" failure such that FDR would be immediately disabled?
I.e. The hull failure/explosive decompression much discussed already. Could it explain immediate FDR cutoff?

Point taken. Semtex-H, rumoured to have be used on PA103 has REF of 1.35 so yield equivalent would have been at max 600g at Lockerbie.

Etud_lAvia, +
Lauda Air 767, reverse deployment at cruise.
Speedbird 911, severe turbulence.

Bomb version close all known holes in the puzzle, so if explosive traces will be confirmed by commission, then I think we will accept it.

Preliminary report due in 10 days.

@ Kulverstukas

The Lauda Air crash (already mentioned by rog747) experienced structural failure after its gross upset, probably because airspeed far surpassed Vne in its dive. It broke up only seconds before reaching the ground. The uncommanded reverser deployment likely resulted from a control system failure, not a structural failure.

The BOAC Flight 911 crash, like mountain-turbulence accidents mentioned previously, initiated far below the regime of cruise altitudes (about 16,000 feet).

Can't really compare the expected results of a different type of bomb placed in a different location on a 747 compared to an A321. The results in loss of life were total but destruction differed.


My main concern is the method of delivery of the bomb and what can be done to reduce risk of recurrence.

Can anyone produce pictorial evidence of what happens when a drinks can packed with explosive is detonated?
What I am hinting at is how might the can fragment?

Apart from the 'peeling' of the skin of the rear fuselage section, there was the 'peppering' of the upper trim panel of the rear door.

Would anyone intending to bring down an aircraft bother to pack 'nails'? - that would be reserved for anti-personnel munitions, Shirley?

Well TWA800 comes to mind as well.
But sometimes it was just luck, that the crew was able to communicate or even bring back the crippled plane.
Like for JAL123 or United 811
Also ElAl 1862 could have happened slightly different and lead to an immediate crash

vice versa there are cases where bomb explosions did not immedialtely tore the plane appart, like swiss 330.

I would currently say that in history the number of both occurences is about the same. We have however learned and improved aircraft design, and we do scrap aircraft earlier today due to their high fuel consumption before they become really old, so structural/system failure leading to an immediate loss should be less probably every day.

Still the bomb theory remains a very plausible one, but without hard evidence I will not yet buy it. Most of the wreakage is found, so finding evidence should be possible. Sooner or later.

About the same result as wrapping the explosive in barbecue grade aluminum foil.

A Buk it ain't. I'd rather not make suggestions on how to maximize damage with the suspect device or supply search terms.

So the aluminium can is unlikely to be what caused the 'rash' on the door trim panel?

Just a point of detail, a ml of pure water weighs one gram. I weighed a can and it came to 375 gm.

If the explosives sinks in water, then it can weight more than 1g/ml. I heard it from Greek guy Archimedes :cool:

PS: C-4 weights 1,44 g/ml so in standard tin can there will be 475g C-4
PPS: 475g C-4 is equivalent to 1.5 x 475 ≈ 700g TNT

And actually a 330ml can has closer to 380ml capacity - there is always ullage in the top of the can.

So you could say if it was C4 you could have something more than 800g TNT equivalent.

Besides that Russian police investigates such possibility, it's greatly unlikely as it was return charter with mostly families aboard. Crew is highly unlikely too as it's small airline and staff is well paid in industry so rotation is quite small.