Beginner jet question
 

Hi All,

I been a fan of RC Universe for some time now and must say that it is very helpful.

I now have a question. I just purchase a used YA F18 with the rhom-air retract installed. However there is a small hexagon screw at the bottom of the main gear. I try to unscrew but none of my hex driver would fit.

Does anyone know the size of this hex screw?

There is also a wheel brake that does not seem to work even after I fill the air canister. This plane is relatively new so I think that it can be make to work. Anybody know what I'm doing wrong and what I need to check.

Any help with be greatly appreciated. Thanks.

David