BEA report-Item not stated
Hi Gentlemen,
I'm an old used military jet type with only steam gage experience, but there was something that I did not see in the BEA report that should probably have been in there at this point.
The size of the recovered wreckage fragments from AF447 appears to be relatively large and this implies a relatively low speed impact with the water (albeit with a large downward vector). I think some of the other old hands have sensed this as well, but it hasn't been explicitly stated.
Having participated in a few accident investigations over the years, I've seen what happens when an aircraft hits the water at medium speeds and at high speeds. Kinetic energy goes up as the square of the velocity. This energy converts the aircraft into a churning mass of fragments which then beat on each other until their energy is dissipated. The higher the energy, the smaller the fragments.
There are approximately 5 minutes of ACARS messages which were coming in at a good clip and probably would continue to come in if the aircraft were still airborne and under electric power. As I understand it, ACARS requires generator power from the engines to be operational.
It would probably require at least 1 minute for the aircraft to decelerate from cruise to stall speed if that is what it did. To then descend from FL350 to the surface in the remaining 4 minutes would take a descent rate of almost 9000 ft min which implies a very deep stall or that the aircraft had some unpowered flight time.
I would imagine Airbus has already worked out the numbers whether 9000 fpm is even possible in a deep stall. If this type of scenario seems reasonable, we can look backwards and see what might have precipitated it. Thoughts?
Sid