Actuators
It looks to me like Cylinder 33 controls the tilt. In the diagram it appears much larger the Cyl 41. From the description, I infer that 33 and 41 have the ability the ability to both push and pull rather than rely on some outside force (aerodynamic in the case of 33 and maybe a spring like force - like a leaf sping - in the locking hook in the case of 41) for one direction. If I'm right, then the pneumatic systems have the ability to apply differencial or equal pressure to both sides of the piston.
Applying equal pressure to both sides of the piston would "lock" the piston in place, but only up to a certain force because the air inside is compressible.
Under this scenario, 33 might provide stability above Mach 1.4, but be overcome (depending upon altitude) by aerodynamic forces in the transonic zone.
Another possibility is that a pneumatic failure in 41 could have caused a premature unlock and the pilot was moving the unlock lever to try to fix it.
I'll be reading the NTSB final report with interest.
Last edited by thcrozier; 11th Nov 2014 at 22:22.