Viewport: Power Hungry
- By J.R. Dailey
- Air & Space magazine, August 2011
"Viewport," by National Air and Space Museum director J.R. Dailey, opens each issue of Air & Space magazine. The column highlights the Museum's ongoing efforts to preserve the history of aviation and spaceflight. This article appeared in the August 2011 issue of Air & Space.
Like many airplane fans, I love the sound of big piston engines. When we hear them at airshows today, pounding from the fuselages of warbirds, we remember all the stories we’ve read of heroism in the skies during World War II. Most of us think of the engines as mere components of the airplanes, when in fact some of the most iconic aircraft in history could not have earned their reputations had it not been for a near-perfect pairing of engine and airframe. Had the Rolls-Royce Merlin V-12, for example, not replaced the P-51 Mustang’s original Allison, the fighter would not have attained the high-altitude performance and range it became famous for. License-built by Packard for P-51s, the Merlin, displayed at the National Air and Space Museum’s Steven F. Udvar-Hazy Center in northern Virginia, helped save many an Allied bomber in World War II. On the other hand, we also have to wonder what the Douglas X-3, the research airplane on this issue’s cover, might have achieved if the jet engine originally intended for it had been used, instead of the lower-thrust engine that was substituted.
A remarkable discovery in 2007 at the University of Palermo in Sicily is giving scholars and others interested in aviation history the opportunity to see aircraft engines in their infancy. There, the Historical Museum of Engines and Mechanisms has just opened its collection of rare World War I-era German engines. These engines show how inventors in the early part of the last century found solutions to the problems engineers still face today: the need to provide the greatest amount of power with the lowest weight. One solution on exhibit in Palermo is the rotary engine, so called because the cylinder block rotated around a fixed crankshaft. The rotary engine eliminated two burdens of in-line engines: a long, and therefore heavy, crankcase and the weight of a cooling system. (Rotary, and later radial, engines were cooled by air and weren’t as vulnerable to enemy fire as water-cooled engines.) We have several rotaries in the National Air and Space Museum. A 50-horsepower Gnome Omega, on display in the Early Flight gallery, is the first in the most successful line of rotary engines.
Rotaries were ingenious inventions that deserve study and attention, but the solution they offered is rooted in the past. To see an engine of approximately the same period that reached toward the future, visit the World War I gallery: A Hispano-Suiza V-8 is displayed there next to one of the many aircraft it powered, the highly capable SPAD XIII. The “Suiza” of “Hispano-Suiza” was Marc Birkigt, an engineer of Swiss descent who worked for an automobile company in Barcelona (the “Hispano”). With its revolutionary compact construction, in which four cylinders were cast into a single block, Birkigt’s engine was one of the most successful in World War I and began the line from which the Rolls-Royce Merlin descended.
J.R. Dailey is the director of the national Air and Space Museum.