Whats the stupidest mistake you've ever made while building?
I did the classic. When I set up the aerlon servos my brain told me that to turn right the right wing airlon deflects down -- seemed logical at the time and was maybe my nth airplane setup.
You guessed it; the plane took off nicely down the center of the runway. After lift off I started to bank to the left and it moved to the right and I banked some more and it finally ended upside down and plowed into the last fence post square on the spinner.
RESULTS: One Hanger 9 Ultra Stick 120 with an OS FX 1.60 power plant and a 3" Tru-Turn spinner and an 18x10 Zinger Pro prop, etc. You do the math. The engine and radio equipment survived but that was all. My assembly took about a month; my dissassembly took about 20 seconds.
Now, I did indicate that this was a classic but it wasn't totally. You see, this was the 2nd Ultra Stick 120 I did this to. The 1st one actually survived the initial ordeal -- I managed to chew gum and walk that airplane back to the ground safely. I actually attribute the 1st occurence survival to my then flying inexperience. Back then a takeoff meant full power and yank back on elevator for takeoffs. That guaranteed I was quite high before I started turning the airplane. Experience taught me to slowly advance the throttle to about 1/2 and then rotate in a smooth shallow climbout. This time when I started to bank out of the takeoff run I didn't have enough altitude to realize I was dealing with reversed airlons.