Summit of the Flat Fours

EAA AirVenture Oshkosh 2023 will see vintage aircraft owners celebrate the ninety-year history of Continental’s storied A-40 aircraft engine—the world’s first horizontally-opposed four-cylinder reciprocating powerplant.

The entirety of the dizzying array of modern, horizontally-opposed four-cylinder aero-engines evolved from Continental’s A-40, and the vast majority of today’s certificated pilots, professional and amateur alike, learned to fly behind such mills.

Introduced in 1933—the selfsame year construction of San Francisco’s Golden Gate Bridge got underway—Continental’s 37-horsepower A-40-2 engine birthed general aviation by making flying and even aircraft ownership accessible to the masses. Flight schools, for the first time in powered flight’s (then) thirty-year history, could afford to purchase, operate, and maintain aircraft powered by Continental’s A-40-2 engine and still remain profitable.

The A-40-2’s horizontally-opposed four-cylinder architecture spread quickly across the automotive, marine, and even motorcycle sectors. Millions of such engines have been produced by renowned marques such as Audi, BMW, Lycoming, ULPower, and Rotax. Nevertheless, for six long years, the A-40 was the only engine of its kind available to light aircraft OEMs the likes of Piper, Taylorcraft, and Heath. Even during the height of the Great Depression more than 2,500 light airplanes were built, all powered by Continental’s dependable A-40 powerplant—the compact size and high power-to-weight ratio of which ushered in an era of four-place, 170-plus-knot airplanes.

As fewer than thirty airworthy A-40-powered aircraft remain extant in North America, the opportunity to see more than a dozen such machines at EAA AirVenture Oshkosh 2023 is unique and ought not be missed. This summer’s event, to be held 24-30 July at Oshkosh, Wisconsin’s Wittman Regional Airport (OSH), occasions the largest gathering of A-40 engines in the last sixty-years. The reunion is being hosted by the Vintage Aircraft Association.

AirVenture 2023 attendees will have opportunity to see the assemblage of historically significant airplanes in Vintage parking and on the Vintage Plaza. Showgoers will also be able to learn more about Continental’s legendary A-40 engine by inspecting a cutaway A-40 in the Vintage hangar.

A-40 owners and pilots are encouraged to take part in this summer’s reunion by contacting Mark Stewart (stewartm@aol.com) for further information.

FMI: www.eaa.org