Have been following this post since news about the unfortunate loss of the Egypt Air flight first broke. Obviously it's far too early to determine what exactly was the cause of the loss of the aircraft. However - and apologies if someone has posted this already - with regard to the theory that an on-board fire may have been a contributory factor, given the smoke-detector messages received via the ACARS transmission...
I just happen to watch the following video on the BBC website of debris recovered from the sea that are purported to originate from flight MS804. If you look at the sky blue material (with what looks like the Egypt Air logo on the reverse side) that is shown from about 4 seconds in, the edge towards the right of the picture seems to show discolouration akin to synthetic cloth being exposed to a head source. At about 7 seconds into the video the shot moves to close up on the material, and centre right of the picture a blackened edge to the material can be clearly seen, which appears to be charring.
EgyptAir: Submarine searches for missing flight data recorders - BBC News
Looking at the following interior shot from a Egypt Air 737 - have been unable to find a comparative shot from and A320/1 but someone may be able to help there - one of the seats to the left of shot appears to have a pillow upon it which is covered in a very similar material in terms of colour and logo to that seen in the video.
http://www.seatmaestro.com/wp-conten...50_1024_WM.jpg
May be nothing, but given the - limited - information we have to hand at present thought I would just mention it.