As we progress well into the second century of flight, most of us take to the sky in machines of metal or advanced composites like carbon fiber and Kevlar. The science is solid and techniques well established for flying machines of these materials. But if you step away from the mainstream types most commonly decorating the ramp at your local airfield, you may well stumble across wooden airplanes that survive as antiques, warbirds and homebuilt designs, as well as a few types built more recently. There are even a few designs in current production—one featured below is a throwback to the days of old, while another is a Light Sport Aircraft utilizing a wood wing to stay below the 1,320-pound gross weight limit.
At the outset of aviation, wood was a logical material for aircraft construction. Lightweight alloys were still anything but common, but wood was widely available and used for everything from bridge timbers and railway coaches to furniture and buildings. Technically, some metal structures did take flight as rigid airship frames before the Wright brothers even started building gliders. But for the first several generations of aircraft, wood was a critical design component. From the early pioneers through the Golden Age air racers, wood allowed for strong structures with a smooth finish that didn’t require rivets disrupting the airflow. It could be used in a number of methods. The earliest flying machines were often a skeleton of wooden frames, with a fabric skin stretched over it. As machines gained speed and a need for strength, plywood skins formed over ribs, stringers and bulkheads made for a strong structure without a lot of weight. Even as aluminum became a popular building material for aircraft, wooden spars, such as on Piper Cubs until early 1946, persisted as a light and affordable component. Many of the lighter Cubs sport spars of spruce or fir. Wood spars continued in new-production Champs, Citabrias and Decathlons until the 1990s.
Even today, wood persists in plenty of homebuilt designs and even a few certified aircraft in current production. Wood is light, strong and, unlike metal, it doesn’t have a “memory.” It either breaks, or it doesn’t. Metal, on the other hand, can be observed failing as you bend a paperclip back and forth several times. With each bend, it deforms more easily, and when it finally does break, it does so with less force than originally needed to bend it. Wood is far from a perfect material, though. Termites aren’t so much a threat as rot—moisture is the enemy. Having a mechanic who is knowledgeable and comfortable with wood structures is key. Let’s take a quick look at 10 types, some old and some new, to see what a broad variety of wooden wonders might decorate an eclectic aviator’s logbook.