First I would point out that I have absolutely no concerns about the safety & maintenance of VS aircraft - If I had I wouldn't be in them at 30,000'
Second Ð I know a little about aircraft Ð I am not an engineer!
Given that I will attempt some amateur comment.
The vital structure of the 744 is a series of frames which run around the circumference of the body linked with stringers which run laterally. They strengthen the pressure hull which keeps the pressurised air inside.
This can be seen in
this photo.Looking at
the damage, the most visible thing is that a large bit of the outer surface is missing. This is simply a fairing Ð it is not in any way structural Ð it simply is there to lower air resistance & turbulence.
The important damage can be seen to the pressure hull Ð the bit painted green Ð which is clearly breached and peeled outwards.
Also many stringers are missing and/or bent out-over. You can see the attachment lines of the stringers in the pressure hull sheet.
The aircraft was above 30,000' ; above 70% of the atmosphere so the inside pressure is considerably greater than the outside pressure. The difference gives a force on the pressure hull of roughly 5 tonnes on every m_. This is aluminium sheet strengthened by those frames & stringers.
There is lots of speculation about corrosion Ð speculation! Any damage or corrosion could considerably weaken that structure. Great lengths are taken to prevent corrosion and frequent checks are made particularly on old air-frames like this one.
Anyone who has had an old LandRover will know what coffee and coke can do to aluminium. This is why great care is normally taken with spillages but it is known that problems can occur beneath the galley & toilets. These areas are normally carefully checked.
The point at which the rupture occurred is also where the oxygen bottles are placed against the hull.
There is also some wild speculation about these bottles but it is fairly clear that if pax bottles had exploded, the passengers would certainly have noticed the lack of oxygen at 30,000'. Bottles are interconnected. Flight crew bottles are on a seperate circuit. One possible difficulty could occur if corroded structure were not clearly visible behind the bottles.
I suspect a close examination of every 744 has already been done in this area!
Any assessment now is entirely speculation. I suspect we may get some authoritative statement soon.