PPRuNe Forums - View Single Post - BREAKING NEWS: airliner missing within Egyptian FIR
Old 5th Nov 2015, 19:13
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Chronus
 
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Originally Posted by lomapaseo
I note a lot of posts about holes in structures and speculative conclusions about bombs etc.

Almost every prang that destroys an aircraft has such. The challenge to the investigator is to assess what velocity was involved and by what type of particle origin.

The vast majority originate from aircraft or engine structures that are forced or pushed outward at no more than the impact vector velocity. The tearing fractures along the hole are classic (tensile shear) in this sense.

Explosive impacts (missiles, bombs and/or uncontained engine parts) impact at much higher velocities (over a range). Thus these holes often have the presence of cratering (adiabatic shear etc.) and/or multiple dissimilar impacts over an area near the hole.

The investigators on scene know this and can be expected to comment if seen.

(note: I haven't seen any comments from them at this time)
Assuming it was an explosive device that brought the plane down, it would not be impact damage that would be the major dynamic force of its detonation. It would be the overpressure caused by the expansion of gases,from a combination or decomposition reaction resulting in a exothermic reaction release of energy partially converted to work. Looking at the various images any significant high velocity particle damage is not readily evident and unlikely to have been the agent in such an event as to totally and completely disable the aircraft in such a very short period of time, possibly measured in fractions of a second.
The whole thing looks more likely to have been the work of an explosive device designed to generate rapid overpressure and hot gases rather than brisance. So reminiscent of the Pan Am 103 Lockerbie disaster scenario.
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