Builder Walter Treadwell has taken on projects that many of us would find daunting, and he keeps upping the ante. First came a Lancair 235, then a plansbuilt Jenny JN-4, followed by a P-38 and then his current project, a resized Sikorsky S-38. Some 4000 hours into the new project, Treadwell has a ways to go, but fortunately he has a mini AgCat to fly in the meantime; by Bob Fritz.