Airbus crash/training flight

[grizzled]

A4, You wrote: "The initial reports of the impact site stated wreckage spread over a wide area. This is normally indicative of a shallow(ish) impact angle as opposed to "spearing in" i.e. very steep impact angle."

That is (generally) a "correct" statement for a land impact, but not necessarily so for water. The specifics of wreckage patterns on, and in, water vary of course, based on many factors that are quite different than the factors at play in ground contact scenarios. Having said that, your post also got me thinking about “impact damage” as opposed to “wreckage patterns”.

Actual “impact forces” are based on four (main) criteria regarding the impacting object (aircraft): forward speed, vertical speed, nose angle at impact, bank angle at impact. The fifth main ingredient is the physical nature of the impacted surface. In that regard there is one important aspect of water impact that many people don’t realise, or are possibly just not aware of the physics involved. Without going into unnecessary detail, water is nowhere near as easily displaced as most tend to think, meaning that the impact forces can be quite comparable to a very hard land surface (concrete, for example). One only needs to read this excerpt (for example) from the CTSB report on SwissAir111: “impact forces were in the order of at least 350 g”. (http://tsb.gc.ca/eng/rapports-reports/aviation/1998/a98h0003/01report/01factual/rep1_13_03.asp )

In addition to SW111, there are many other examples of incredibly – almost indescribably – strong impact forces where the CVR and FDR were virtually undamaged or barely damaged. Most “failure to read” scenarios result from fire or heat damage as opposed to impact damage, and there are very few cases of water impact (no matter how severe) wherein the CVR and FDR have been damaged to a point of yielding little or no information. My point (finally . . .) is this: Given the known circumstances of this horrid occurrence, I will be quite surprised (and, I admit, a tad suspicious) if it turns out that either the CVR or the FDR are so damaged as to preclude them providing adequate and accurate information.

Grizz