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dakka
05-24-2005, 05:07 AM
Hello everyone, I have just become a member after about a year of reading the posts on this site. I am building a supercub from scratch using the Northland plans. I noticed on the Smith cub there was a tube which goes from the bottom of the firewall to the fwd cabin post, my plans do not have this, can anyone tell me what size this tube is and why Smith have added it to there cub?
Thanks in advance for your reply's.


Dakka
Australia

Ron B.
05-24-2005, 06:35 PM
The tubings are 5/8" in dia. , I do believe , I can check tomorrow. They were added to help support the larger hp engines.

Frank T
05-24-2005, 07:04 PM
WagAero also uses this tube in their 150hp Cubby. They show it as a 3/4 x .035 tube.

Frank

fobjob
05-25-2005, 02:06 AM
As I recall, it's to prevent the pilot's legs being broken on impact by the engine tucking under, bending the firewall up and back.....it should be larger (in my opinion) than 3/4 .035, maybe the same as the up tube to the top of the firewall from the bottom of the door frame...

Steve Pierce
05-25-2005, 07:11 AM
I think fobjob is correct. There are several certified Cubs that have had this tube added. There was a thread along time ago about this. I think a lot of accidents caused pilots to get trapped by their legs because the firewall caved in at the bottom.