Kyle Boatright wrote:

1) Isn't the screw jack "sized" for air loads, with some sort of over
center mechanism to handle the ground loads?

Thinking about it some more, you're probably right in a way. Although there isn't any
over-center mechanism, there would normally be little pressure on the screw mechanism
once that knee joint section straightens out. It's probably sized to keep the joint
straight and can't take the load when the joint begins to fold.

George Patterson
If you don't tell lies, you never have to remember what you said.