AF 447 Search to resume

[bearfoil]

henra

Of course it's tiresome to read the same thing again and again. My point all along has been the lack of attention paid to this crucial piece, and further, I believe it to be a patent example of a design that ignores the relative importance of each of the control surfaces. Here in AF447, the Rudder as always remains. You may not recognize the problem, but aerodynamically a Rudder is a trimming device, a Vertical Stabilizer keeps the nose into the wind, without it, an aircraft can not fly.

In AA587, it is claimed the F/O is responsible for ruddering the V/S and Rudder off the aircraft. This "bicycling" of the Rudder pedals seemingly snapped off all directional discretion, the Airbus almost immediately shed an engine due to immense axial stress.

In AF447, the RTLU is proposed to have limited travel of the Rudder to 4 degrees either side of center, an amount calculated not to overstress the assembly at Mach.82. With RTLU FAIL on the list, It is arguable the Rudder was not limited, and may have been subject to full travel as if the a/c was at <250 knots. This too could have allowed the Vertical fin to bite off too much of a Mach.82 airstream failing in much the same way as 587.

I understand the RTLU was removed and tested to 7.9 degrees, a result that to me proves absolutely nothing. If a Rudder blows off its mountings,the VS remains, providing directional integrity. If on the other hand, a Rudder stays with, and the VS is torn off due to Rudder input, we cannot fly, period. It is telling that Airbus includes Rudder limiting; I am saying it could be taken a bit further.

The 330 has massive mounts (six of them) rooted deep into the Tail/Fuselage, but they failed. It is difficult to picture a vertical impact simply causing the VS/Rudder to plow down into the Body, then symmetrically rebounding, having taken the fuselage pieces with it.

Without suggesting the reason for the loss of VS, it would be easier to envision the tail with part of the fuselage attached impacting the Sea inverted, with the tail hitting first.

To say that it was merely momentum that failed the VS begs entertaining a fantastic sequence. It has been difficult to picture this massive aircraft having directional and aerodynamic problems at 37k losing all its forward speed quickly, then recover in some fantastic way to impact "en ligne de Vol" . Let's not forget that the "rotation" to the left at impact seems to have miraculously preserved the V/S structure in all its dimensions. Given the appearance of both fins, a loss at altutude for 447 is the simplest explanation, as there is precedent in 587.

Of far more interest is the chain of faults that caused a unique result from a problem that had happened many times prior. It's in there, it is.

jcjeant

Captain not seated? FA's not seated? No warning from cockpit? No Mayday? These pilots were in the swamp very quickly perhaps wrestling to regain control, g forces could easily have prevented anyone from donning flotation. If no air at altitude, consciousness is lost at 40 seconds tops.

rgds. bear