While the National Business Aviation Association is almost always identified with issues affecting the operation of turbine-powered business aircraft, more than 1,000 of its member companies operate piston-engine light planes to support their business travel.

Whoa. Wait a minute. Stop the presses! Wasn’t unleaded automobile gasoline (so-called “pump gas”) approved for use in some engine/airframe combinations years ago, at least for the smaller piston engines, e.g., the Lycoming O-360 installed in thousands of Cessna 172s and other light planes?

A small population of large (“heavy”) transport and vintage aircraft powered by commensurately large air-cooled radial and liquid-cooled inline piston engines remains active in the U.S. and abroad that cannot be operated on any fuel other than 100/115-octane leaded aviation gasoline.