mm43
The vertical movement of the Rudder is not "upwards and downwards". Here, "vertical" refers to the sweep of the Rudder (Loading) as a vector 90 degrees to the Vertical Stabiliser measured spanwise. The "designed for" load is "sideways". ("vertical") Hold a model of the a/c level, then roll it 90 degrees. As the Rudder articulates "up and down", this is your "vertical". (relative to the VS.)
This is why the member is called an "arm"; the two arms support the pivot hinge of the Rudder, but their purpose is to transfer pivot stress outboard of the axis of the Rudder Pin into the aft vertical spar of the VS.
They work "independently" of eachother, as the rudder expresses side loading alternately as a compression or a tension.
The failure of R36g is in tension, evidenced by the "breaking off" of the tip of the thru-bolt mount. This is indicative therefore of an unsustainable load while the Rudder is deflected to the Right, Starboard side of the a/c centerline. If intentional, it would be evidence of an attempt to mitigate left Yaw.
I'm in no position to critique the esteemed engineers of the aircraft, but I have at least two questions.
Is there not a "saddle" washer between the Pin/Tube and the load face of the thru-bolt/arm? I would expect one, since to load a flat arm to a round tube without spreading the point stress would not be a good thing.
Finally, and this thus far only applicable to the AB300-AA587:
Has the designer of the Rudder been apprehended? Likewise the VS team members? What about the "fusion" team?
The Rudder loaded the VS to its catastrophic breaking point, and the Rudder remained attached to depart the VS after the VS/Rudder system was torn away. Forget the F/O and his alleged "bicycling". Had the Rudder failed and torn away, they would have landed almost certainly. Plenty of time to lease a flat bed Truck and retrieve the Rudder from the Orphanage.
I would only repeat, an aircraft can fly reasonably well with no Rudder at all, it is after all, only a "trimming" device. Without a VS, it will not fly.
At all.
What's wrong with a picture of a Rudder attached to a Vertical Stabilizer, but the Vertical Stabilizer is unattached to the Aircraft?
Fatal or no, Hull loss or no, procuring cause of the Accident or no?
It cannot be ruled out that the VS separated after the a/c's impact with the Sea. However, it is too pristine to have occurred that way, imo.
Was it thrown clear (completely) then? Because if it was floating with other debris, to include heavier parts that subsequently sank, there is no abrasion, dimples or punctures, and in a rough sea (!) at that.
In the scheme of things, 36g acceleration is not much at all. Lap belts are stressed to perform through 40g's, since stronger than that, people are sliced in two, and it becomes a moot specification. (sorry to be blunt).
At 36 g's the crew rest capsule, the galley, and the lav door would be accordioned to the size of a briefcase, imo. These structures are simply not built to withstand crushing, twisting, or frankly, to support their own (unattached) weight.
The VS. If I was a responsible party in this tragic accident, and the VS was found unattached but especially with the Rudder yet attached, I would pray for the conclusion of "lost at impact". For if it failed prior to, I would consider it a suspicious thing, perhaps related to the outcome. I certainly wouldn't say the a/c landed "En ligne de Vol" and intact. The two must be sustainable in the evidence.
bear
Last edited by bearfoil; 5th Mar 2010 at 00:07.