jcjeant
In searching for a compelling composition of evidence to inform a "small horizontal component" of velocity, I look at the engineering involved in plain sheet design. It is not an accident of design that aircraft are built to resist longitudinal loads far more than "Horizontal ones". Tailstrikes, slips and skids, excessive Yaw are simply not primary considerations in commercial and utility a/c. It is assumed that flight aspect other than trimmed longitudinal is an aberration, forced upon a pilot(s) by artifacts of poor design, poor training, mechanical deficit or other "unusual" (and unexpected) circumstances. In flight, a "slippery" a/c is the goal, as evidenced by stowed (in flight) aero devices: Flaps, Slats, and Rats. Reconfig is an essential part of modern flight, where an a/c must be a truck and a bird, (hopefully not at the same time!). 447 experienced other than trimmed flight by definition (per ACARS: a/p drop). A water entry in vertical aspect is as far from designed for considerations as man can get. I wonder about BEA's "conclusion of low horizontal" velocity. An a/c is much more able to resist lengthwise loads than vertical. In flat vertical impact, evidence of this "design" is apparent, as in CAL Denver and Turkish Schiphol. Vertically, the a/c really is a "tube". Cylinders (fuselages) as structural concepts are meant to handle "bearing" load, not "rectilinear compression". Per Machinbird and his post, it is at "splices" (joins) where most of these failures accur. It is a consideration of "poly-geo" construction that we see this. Where once Vertical, horizontal, and spanwise elements were built as a unit, in one location, we now see fuse, tail, wing, and engine pylon/engine assemblies borne across Oceans on ther decks of freighters, or in the hold of high lift a/c.
An example would be the nose fail of the 737 at Schiphol and Denver, or the Tail assembly of AA587 La Guardia. Looking at bare brackets where an epoxy tab is missing is part of the "new" engineering. Do I disagree with this approach? Only when it causes the loss of an a/c and its people.
bear