UK SIS and other countries' threat responses
Most intelligence gathering operations are long term exercises. The UK's various Secret Intelligence Services co-ordinate threat analyses over different timeframes; short term/immediate threats are usually identified as a result of significant activity on nodes of interest (cell phones, emails, skype, tor activity etc).
My wild speculation is that the UK response is based on massive increased node activity in the region leading to perception of a credible threat to leverage on the existing disaster.
Perhaps perversely, I continue to suspect this was not a terrorist act. I don't subscribe to the APB theory (after JAL123 that ain't going to happen again) or most other theories based on prior events (the purpose of accident investigations is to prevent recurrence, unless there's a serious cock up like DC10 cargo doors).
The strongest part of a fuselage is supposedly the bonded/riveted joints around stringers. Skin is designed to rip in the event of overpressure (eg by explosion) whilst structural integrity is maintained.
I just cannot understand the relatively clean unzip along rivet lines at the tail before the PB in front of the leading edge of the VS. This looks like a fatigue fracture, and its location is spot on for an overcompression of the joint following a tail scrape.
Explosive decompression following a rip explains particle velocity dents.
Aft fire damage is more problematic, but the APU fuel line appears to have been severed some way back into the aft cabin (there's a long length of hose still attached), and I can imagine a few sparks flying around from severed electrics.
In my full scenario, the floor structure means the tail does not separate immediately, leading to the relatively slow descent, rapid deceleration, and lowish impact v.
Last edited by peabrain; 5th Nov 2015 at 23:59.