Beginning with daVincis gliders, fabric has covered our flying machines. In the early days, cotton or linen was sewn to the airframe, shrunk somewhat with water, then painted with a cellulose-based coating called dope to further tighten and protect the porous fabric. That protection wasnt complete, however, as organic fabrics are subject to rot from fungi that eat the fiber. Nitrate dope was initially used, but its disadvantage was that it burned ferociously when ignited. An early cover job might last for only a handful of years, if it didnt catch fire first.

During World War II, butyrate dope-sometimes referred to as CAB for cellulose acetate butyrate-was found to be less flammable, so it replaced nitrate and continued to be used over cotton and linen for years. But fungus could still be a problem. The typical lifespan of a butyrate dope covering was seven to 15 years, although a few well-preserved airplanes still carry their decades-old cotton/dope skins. A friend of mine has a 48-year-old Tri-Pacer wearing its original cotton fuselage fabric. (Its scheduled for recover this year.)

In the 1950s, heat-shrinkable polyester fabrics were introduced, reducing the time required for installation because the fabric could be glued rather than sewn to the airplane. Other than the rare museum restoration that uses organic fiber for authenticity, polyester fabrics are used almost exclusively these days. Polyester is stronger than natural fiber, easier to work with and not susceptible to fungal rot, although sunlight will deteriorate the unprotected fiber.

A small problem is that butyrate wont stick to the slick synthetic fibers, so the old nitrate dope is used for the first coat, then butyrate is applied thereafter. Increasingly though, more modern vinyl- and polyester-based coating systems are replacing traditional dope, but with any of the systems available today, a properly executed cover job should last 30 years or more.

Should you be afraid of a fabric-covered airplane? Not necessarily. In fact, in many cases, the airframe of a fabric airplane is in better shape than its metal-skinned contemporaries. Most older fabric airplanes have been re-skinned at some time in their past, along with inspection and refurbishing of the inner workings at the same time. When was the last time you heard of someone pulling the skins off an aluminum-covered airplane to see whats underneath?

An added benefit: Fabric skin isn’t structural. If a bear bites a hole in your metal moose-hauler, you may not get home, but a few claw marks wont weaken the structure of your rag wing. In fact, many airplanes (notably the Stinson 108 series) underwent “metalizing” about 40 years ago, back when a fabric recover job was viewed as temporary. Today, with the advent of better materials and coatings, many of those same airplanes are being “de-metalized” and returned to their original, lighter fabric coverings. There’s a reason why many hard-working bush airplanes and ag aircraft have fabric coverings, which are tough, durable and easy to repair.

But nobody alive knows how to repair these old crates, right? Truth is, fabric covered airplanes are more numerous than ever-more than 34,000 are registered with the FAA, a number that grows daily. Some 3000 airplanes are recovered each year, so there are plenty of shops practicing this dying art that isn’t dying at all.