Last October, a California entrepreneur named Leonard Johnson set out on a transcontinental flight to First Flight Airport in Kitty Hawk, North Carolina, in a homebuilt airplane powered by “bio-butanol,” a fuel obtained from fermented plant material. Butanol is a form of alcohol like the ethanol that’s blended with automotive gasolines; the butanol molecule has a chain of four carbon atoms instead of ethanol’s two. The extra two carbons make butanol a bit more like gasoline than ethanol is, giving it such properties as greater energy density—an important factor for vehicle endurance and range. Johnson’s goal is to replace the 100-octane low-lead aviation gasoline that currently powers light airplanes with butanol made from plants.
His Cozy, a four-seat canard configuration that looks like a larger version of a Vari-Eze, was powered by a four-cylinder Lycoming O-360, which is rated at 180 horsepower when it runs on avgas. Using parts supplied by sponsoring organizations, mechanics modified his engine to run on butanol. On October 28, Johnson took off from Chino, California, and made his first stop, at Amarillo, Texas. At the next planned stop, Fort Smith, Arkansas, Johnson took off but immediately experienced a problem and returned to the airport to deal with it: The number-three cylinder, installed only 30 hours earlier, was running hot and causing the engine to run rough. Tim Rogers, a local mechanic, found small cracks around the spark plug seat and replaced the cylinder, but the problem recurred en route to the next stop, Memphis, Tennessee.
In Johnson’s account of the flight, which he posted on his Web site (www.looklocal.org), he notes that experimental aircraft often use electronic ignition instead of traditional aircraft magnetos to generate spark in the engines. They also may use automotive-type spark plugs, which, under certain circumstances, may not prevent hot gases from leaking out of the cylinder near the plug. On this long flight, those hot gases had leaked and, like a torch, created a passage where air could enter the cylinder, causing the mixture to run too lean at high power settings, thereby overheating the cylinder.
Once again ship-shape, Johnson made it into First Flight Airport on Sunday, November 2, and received a miniature replica of the Wright Brothers National Memorial from the First Flight Foundation. He even got to dine at the very restaurant where Orville and Wilbur are said to have sent the telegram announcing their success in 1903.
For the return flight, Johnson switched to avgas, and on the first leg he experienced yet another overheating problem. As he attempted to make a precautionary landing in Osceola, Missouri, he ran into high winds and lost control. The airplane hit some power poles and lost both wings. Although seriously injured, Johnson survived, and his belief that technology—and plants—can provide future fuels for our aircraft survived with him.