The wing is not fully sheeted. I only have 2 flights on mine so far, but I really like it. I am running an OS .46 FX with the Macs pretuned tunedpipe. I did not rebuild or reinforce my tail section. I think the tail problems talked about in earlier posts may have been caused by flutter. The CA type hinges seem a little more likely to have flutter than other types. I sealed both sides of all my hinge gaps with monokote trim. This has worked well for me in the past.