- May 27, 2019
My first airplane was a light minature aircraft 87% 2-place Taylorcraft replica. I built it of Douglas fir and left the dimensions as per plans. It’s supposed to be 25% heavier than Sitka Spruce but about 25% stronger too so in theory you can reduce dimensions. Douglas Fir is a perfectly acceptable alternative to Sitka Spruce. I didn’t worry about the extra few pounds in the entire airframe as I’m 10 pounds lighter than the “average pilot” (170 pounds) and judging by most of the other builders I’ve talked to the “average pilot” is in reality 20 pounds plus lighter than the actual pilots flying these homebuilts. Being a woodworker by profession I’ve worked with many types of wood. For my current build I researched every type of tree that was similar to the Sitka Spruce. I looked up the various strengths and loads of Sitka spruce and then did a comparison. I also researched builders sites such as the pietenpol builders site to see what has been used. One type of wood that comes extremely close to Sitka Spruce in every category is Bald Cypress. It grows in the southern states, it is relatively rot resistant, grows in tall straight trees, nice straight tight grain, is light, and withstands season after season of tropical storms and hurricanes. It works very well and at least here in the southern states is easy to find and reasonably priced. I would highly recommend that anyone building in the southern states get on line and look up the specs on Sitka Spruce, then do the comparison. You’ll be surprised. Then get yourself a nice board of it and cut into sample sticks and do some tests on it. You’ll be even more surprised!That is how the Sopwith planes did it to.