the wing splits the slip stream and this is what causes it, dead air >in front of the >leading edge. Static and pitot should be together like AFY to minimize >error, >Adrian ++++++++++++++++++++++++++++++++++++++++++++++++++++
The system outlined on page 74 of the manual works just fine with very little error, or at least it does in my case. The manual cautions you to extend the pitot/static tubes at least 2 1/2 inches below the wing to eliminate error. I think I went about 4 inches with mine and it appears to be accurate to within a few mph at cruise. In a no wind condition it matches my GPS ground speed to within 2 or 3 mph. It is less accurate at high angles of attack as any fixed system will be. The best part is that it doesn't get broken off or bent from people walking in to it. The lead edge of my P/S tubes are behind the lead edge of the wing. To mount, cut a small rectangular piece of thin aluminum, drill two holes for the P/S tubes that touch each other, form the alum to the shape of the lower wing surface, slip the alum over the tubes and use some 5 min epoxy (JB Weld,etc.) to secure the tubes to each other and to the alum plate. Use screws or bolts through the skin to attach. Some type of reinforcement on the back side would be advisable. Scrape out some foam on the inside and flox in a small piece of alum or 3/32" ply with some blind nuts or equivelent. If I had P/S tubes that extended even 10 inches forward of the lead edge and there were hugh errors, I'd be looking for other problems in the system besides the P/S location / length. I've seen a 4 inch pitot tube sticking out of the nose of a pusher that seemed to work just fine. As always, your results may vary......... Larry Flesner
