upper & lower longeron size

[mbarkeralaska]

Hi folks........ I posted this also on the facebook group..... but chasing an issue on this project I absorbed.
Hoping it is not a "show stopper".
I was mocking up the landing gear for some final drilling and mounting, and finally noticed that that upper and lower longerons are not 1"x1".
It appears that they are full length pieces, 1"x 7/8". The 1" is top to bottom; the 7/8 is width.

a. In the tail section, aft of the elevator bell both top and bottom longerons are 1x7/8; except where the appropriate gussets are.
b. Forward of the bell crank, they are laminated up to 1x1".
c. In the cockpit areas, and forward, they are laminated up to either 1x1" or double laminate to 1x 1 1/8".

I am now hyper-measuring everything -- butit looks like all four longerons started at 1"x 1 7/8".

Right now I am searching all the forums, and this group, and all the plans and documents I have for these machines. I find a few discussions, but looks like most folks are doing 1x1. There are some helpful facebook comments about the issue.....Would love to hear your thoughts.

Hope I don't have to stop the project, but want to be safe.
thanks
Mark

[taildrags]

Mark;

My set of plans went with N41CC when I sold the plane, but I still have the 1932 Flying & Glider Manual and the Piet plans in that book appear to show 1"x1" top and bottom longerons from firewall to tail post.

Oscar Zuniga
Medford, OR
former owner/pilot of Air Camper NX41CC, A75 power

[Tim]

I’d be surprised if you can get anyone to say on a public forum that smaller wood sizes than the plans are okay, especially when no one has seen the wood species or quality.

If it were mine I’d be looking at similar designs and seeing what longeron sizes they went with. The list of open cockpit wood two seaters with truss fuselages is relatively short but some data is better than none. Fisher Celebrity comes to mind as one place to start.