History of AirplanesThe rotary engine was an early type of internal combustion aircraft engine, used mostly in the years shortly before and during World War I. By the early nineteen twenties the rotary aircraft engine was becoming obsolete, mainly because it could not operate efficiently at speeds greater than approximately 1600 RPM.
In concept, a rotary engine is simple. It is a standard Otto cycle engine, but instead of having an orthodox fixed cylinder block with rotating crankshaft as with the radial engine, the crankshaft remains stationary and the entire cylinder block rotates around it. In the most common form, the crankshaft was fixed solidly to an aircraft frame, and the propeller simply bolted onto the front of the cylinder block.
The effect of rotating the bulk of the engine’s mass was an inherent large gyroscopic flywheel effect, smoothing out the power and reducing vibration. Vibration had been such a serious problem on other conventional piston engine designs that heavy flywheels had to be added. Because the cylinders themselves functioned as a flywheel, rotary piston engines typically had a power-to-weight ratio advantage over more conventional engines.
Like radial engines, rotaries were generally built with an odd number of cylinders (usually either 7 or 9), so that a consistent every-other-piston firing order could be maintained, providing smooth running.
Here are posts about airplanes powered by rotary engines.
How do you fire a machine gun through the arc of a spinning propeller? Early in 1915, aviators engaged in the First World War wanted to solve that problem. Obviously, the bullets of the machine gun would smash a propeller to bits. So far in the war, German, French, and British airmen had fired [...]
This late variant of Nieuport’s biplanes was used mainly by American squadrons, the French having switched over to Spads.
The Type 28 looked quite different from the earlier Nieuports: it had a longer, rounded fuselage; it dispensed with the sesquiplane configuration (and the associated V struts); and it had rounded, not angular wingtips. A very distinctive [...]
The most successful of the Nieuport biplanes of WWI, flown by the French, British, Americans, Italians, and Russians. Often referred to in contemporary sources as the “15 meter” Nieuport (based on its total wing surface).
During the summer of 1916, many months after the appearance of the Fokker, the French produced the Nieuport 17, armed with [...]
With a distinctive large spinner, the Morane-Saulnier N looks, at least to the modern eye, better than the Parasol Type L, it met with much less success.
While the Type N was a graceful-looking aircraft, with an advanced, aerodynamic design, it was not easy to fly due to its stiff controls (using wing warping instead [...]
Similar to the Sopwith Tabloid, the Martinsyde S.1 also served as an observation airplane in France. It only remained in service until summer of 1915; only 60 were built.
Top Speed: 84 m.p.h.
Manufacturer: Martinsyde
Year: 1914
Engine: 80 h.p. Gnome rotary
Wingspan: 21 feet
Weight: n.a.
Armament: none
Martinsyde was a short-lived British [...]
One of the most notable developments at the end of 1913 was the appearance of the Sopwith ‘Tabloid’ tractor biplane. This single-seater, fitted with an 80 horsepower Gnome rotary engine, had the remarkable speed (for those days) of 92 miles an hour. A still more notable feature was that it could remain in level flight [...]
This was the last of the B.E. (Bleriot Experimental, and then British Experimental) series built by the Royal Aircraft Factory. Compared to the B.E.2, it had a more powerful rotary engine, but otherwise was quite similar. It could only carry a 100 lb. (45 kg.) bombload, even less with a two-man crew. A few [...]
One of the fastest planes of its time, the Bristol M.1C monoplane fell victim to official concern about its stability and the perceived hazards of its high landing speed. There seemed to be an official distrust of monoplanes by the British authorities, and the M.1 was much-delayed. Finally some were sent to the [...]
An unusual-looking biplane with a reverse stagger of the wings, the upper being set back just aft of the cockpit, to allow better visibility for the pilot. The idea was to combine the superior performance of a tractor biplane with the unobstructured pilot’s forward view of a pusher type.
In May, 1917, No. 24 and No. [...]
For World War One, the Morane-Saulnier A-1 had very modern lines and was very streamlined; it resembles small airplanes that you can see today at any general aviation airport. 1,210 were produced, but it never made a big impact at the front. Not long after its introduction it was withdrawn to serve as trainers, as [...]