The high sea waves "config" at impact moment is an important factor for parts damage and crash dynamics? Quite probable "rough seas" at estimated crash location? What kind of waves in ft?
The Brazilian MSL analysis for the South Atlantic and Tropical North Atlantic at 2009-06-01 0000z is reproduced below.
There are two distinct features associated with the "sea state". They are categorised as:-
- Local wind generated waves - known as the "sea" state.
- Regional effects from pressure systems - known as the "swell" state.
In the case of AF447, at the time of the accident there was a High pressure system lying to the west of the Canary Islands and the clockwise wind circulation had created a long period swell which was evident at the crash location. The swell was from 060°T with a height of 2m, a length of 330m, and a period of about 15 seconds. There was probably a secondary long period swell with negligible height emanating from the South Atlantic. Localised winds of up to about 25/30 knots created by random circulations associated with the ITCZ will have created a short period sea which could range from 0.5m to 1.5m in height with a period of around 1 - 2 seconds.
Oscar/NOAA satellite data for this period shows winds from the NNE at 25/30 knots, but due to the nature of the ITCZ circulations, it is not possible to identify if that wind was for real.
Those who have viewed the
test tank ditching video provided earlier by
BJ-ENG will note that a high wing transport aircraft making a controlled ditching in optimum sea conditions inevitably suffers some damage. Once the aircraft had entered the water, it often lost an engine or two, or MLG if extended, but that had very little effect on the direction taken until the non symmetrical drag had effect when the majority of its speed had been arrested.
The reality of the AF447 impact is that it was not a controlled ditching, and the Rate of Descent was such that as it "pancaked" into the sea, any forward/crab momentum was arrested immediately by its self generated tsunami. The aircraft effectively disintegrated around the footprint it made at impact.