RE: Wing Hold Down Bolts Question
Like Jeff said - just use a 1/4 by 20 steel hex head bolt and slide it inside the D. Brown arrow shaft. A small local hardware store will sell these bolts as fully threaded up to 5 inches long. You can cut off what you don't need. The arrow shaft prevents any overtighening of the bolts - it will not compress. I use this method on all my planes, including the Yellow Zero. Some are 50 pounds plus and I have never had a failure.