Extra foam block for Chapter 10?

[rnbraud]

Hello all,

 

I am just starting Chapter 10 and am cutting out the foam cores. When I inventoried my order, from Wicks, I noticed it listed two (2) blocks of 7"x14"x64" and two (2) blocks of 7"x14"x41" foam blocks.

 

Now I see where the two 64" blocks are used for the left and right side of the canard. However, I only see where one 41" block is used for the center core.

 

What is the other 41" block for? I hope it is extra, since I screwed up cutting my center core and need to make a new one.

 

Thanks.