Engines Propellers Other Tools of Control
While wings proved to be a successful way to lift an aircraft, what would power and propel it into the sky? And once up there, how could a pilot control its movement in three-dimensional space?
Early aircraft designers approached these challenges by developing different types of engines, propellers, and devices to control a flying airplane. By examining the objects in the Museum's collection, we can piece together the story of how early aviators learned to control and power airplanes.
Powering an Aircraft: Engines
“…the navigation of the air is certain to come so soon as a motor could be discovered which had sufficient energy in proportion to its weight.”
-Hiram Maxim, inventor, 1891
Early engines had to be powerful enough to propel the aircraft into the sky, yet light enough so they didn’t weigh the aircraft down and keep it from taking off. Most engines of the time powered land vehicles, where their weight was not an issue. Adapting these engines to aircraft was one of the greatest challenges in building a successful airplane. Four types of aircraft engines were used: inline, V-type, radial, and rotary. Each had its advantages and disadvantages.
Inline Engines
Inline engines, with a single line of cylinders, already powered most cars. Because some were made from new, lighter aluminum, they made sense for airplanes. But they were water-cooled, and the added water weight meant early inline engines were generally heavier than air-cooled engines.
The original Wright brothers engines were four cylinder types. In 1910, needing a more powerful engine for the Gordon Bennett Cup Race, the Wrights built a single V-8 for this major event using much of the design concepts from their four cylinder designs. However, the aircraft and engine were wrecked before the race.
Faced with the problem of providing increased power for production aircraft in 1911, but insisting on their original objective of simplicity, the Wright’s compromise was a vertical six-cylinder engine. In 1913, the Wrights improved their 6-cylinder engine by incorporating a flexible (rubber band) drive on the flywheel which greatly reduced vibration and considerably extended the life of the chain drive that operated the propellers. They also added a throttle to control the speed of the engine in flight, and increased horsepower. The new Wright 6-70 powered the two Wright Model D aircraft built for the U.S. Army in 1913. Notice the line of cylinders along the top of this engine.
V-Type Engines
V-type engines have pairs of cylinders. French designer Léon Levavasseur patented the most popular V-type gasoline engine, the V-8, in 1902. His compact V-8 Antoinette engine became a favored choice for aircraft in Europe. In the U.S., aviation pioneer and inventor Glenn Curtiss designed and built some of the most successful early V-8 engines. Like inline engines, V-types were often water-cooled.
Why is a V-8 engine called a V-type engine?
V-type gets its name from having its cylinders arranged in two rows that appear as a “V” shape when looking from the front. The number 8 tells how many cylinders there are.
Among the most successful early engines marketed in the United States were those designed and built by aviation pioneer and inventor Glenn Curtiss in his factory in Hammondsport, New York. Early Curtiss engines were designed to power motorcycles. A Model B-8 engine was used by Curtiss in his first design, the June Bug. The aircraft won the the Scientific American Cup, the first aeronautical prize ever awarded in the United States. Unlike all later Curtiss engines, it was air-cooled.
This Curtiss B-8 in the Museum's collection was donated by George Spratt. In 1911, Spratt's father, Dr. George A. Spratt, used the engine to power an experimental seaplane of his own design.
Radial Engines
Radial engines have two or more cylinders arranged around a central crankcase, or hub, which provides smoother operation. Because most radials are air-cooled, they are generally lighter and provide more power for their weight than water-cooled engines.
Italian motorcycle engine manufacturer Alessandro Anzani produced a line of radial engines that were popular among early aircraft builders. He produced his first aircraft engine in 1908 in France. This Model A 2, introduced in 1910, was an improvement over earlier Anzani 3-cylinder, air-cooled, fan-shaped engines, and powered Deperdussin, R. Sommer, and Blériot XI aircraft. Anzani engines were also manufactured in England and Italy. By 1913 Anzani was producing no fewer than seven types of aircraft engines. An 89kW (120-hp), 10-cylinder model was used by Clyde Cessna in his first aircraft. Bellanca was another American aircraft manufacturer that utilized later Anzani engines.
Rotary Engines
Rotary engines may look like radial engines, but they are attached to the airframe only by a crankshaft. The entire engine rotates with the propeller. Rotaries, popular for their simplicity and adequate cooling at slow speeds, powered many early aircraft. However, rotary engines were tough on early pilots who had to manipulate the fuel and air mixture—serving as a human carburetor—as well as try to steer while dealing with the gyroscopic effects of a spinning motor. These issues, plus improvements in radial engines, made rotaries obsolete by the end of World War I.
The French Gnome engine, developed by the Seguin brothers, introduced the rotary to a broad aviation market. This is the first Gnome engine made. More than 20,000 Gnomes of different models were made by the end of World War I. The person who donated this engine to the Museum, Rear Adm. Lauren S. McCready, USMS, was given it by Amédée Seguin, son of Louis Seguin, co-inventor of the engine.
This artifact was first installed on a seaplane which made an unsuccessful attempt to fly from the Seine River. Henry Farman installed the engine in his biplane which first flew in April 1909. In August 1909, at the first aviation meet in Reims, that aircraft won the Grand Prix with records of distance and duration. The engine was later installed in L. Paulhan's aircraft and set another distance record. The first successful seaplane flight was made by Henri Fabre in March 1910, in an aircraft powered by another Gnome Omega engine.
Powering Forward: Propellers
“Well, our propellers are so different from any that have been used before that they will have to either be a good deal better, or a good deal worse.”
-Orville Wright, 1903
While the choice of an engine is critical, propellers are the second half of the power equation. They convert the engine’s power into thrust to push the aircraft forward through the air. The Wright brothers invented the modern propeller. They were first to realize that propellers acted like wings. The Wrights used their wind tunnel data on wings to help make a propeller far more efficient than those of other early experimenters, such as Langley.
Other manufacturers soon made designs of their own. To help take full advantage of the advances in engine horsepower, designers experimented with many different propellers to try and find the most efficient one. Explore some of these designs from the Museum's collection below.
Bastow-Page Airship Propeller
This propeller was designed and built by Stuart Bastow, an electrical sign contractor, and Victor Pagé, a mechanical engineer, for the dirigible Rhode Island in 1910. It was the first metal propeller that could be adjusted on the ground. Bastow bought a bamboo and fabric propeller and the propulsion system from Capt. Thomas Scott Baldwin's California Arrow. Pagé, unsatisfied, suggested constructing a propeller from aluminum, then a relatively new, but proven material, because of its light weight and strength.
Not knowing which pitch setting would be best for the dirigible, except through trial-and-error, they designed the propeller to be adjustable. This resulted in the earliest American attempt at multipiece construction that allowed for the pitch of the propeller to change deliberately, changing acceleration and speeds of the aircraft. This propeller emerged unscathed during several forced landings, which indicated its inherent performance and durability benefits.
View Bastow-Page Airship Propeller object record
Simmons Propeller
James Lee Simmons began designing, experimenting, and making propellers first at his Washington Aeroplane Company factory located on Water Street in the southwestern area of the District of Columbia during the 1909-1910 period. By 1913, when this propeller was manufactured, the company also manufactured a line of "Columbia" monoplanes, biplanes, and flying boats based on European and American designs.
Like other early aircraft manufacturers, Simmons also fabricated Wright-type propellers for $100 (approximately $2,000 in modern currency) a pair, as well as variations of Chauviére and other French designers in two-, three-, and four-blade configurations.
View Simmons Propeller object record
Requa Gibson Propeller
In 1909, the Requa Gibson Company of New York City, led by Hugh C. Gibson, became the first American propeller manufacturer. The company began by crafting copies of Chauviére designs, but it then pioneered distinctively American designs by E.W. Bonson. The success of this pioneer propeller manufacturer was short-lived, as the company went bankrupt in June 1911.
This Requa Gibson propeller was used by Professor David L. Gallup in experiments at Worcester Polytechnique Institute from 1911 to 1913. The Gallup whirling arm experiments were one of the first comprehensive attempts to test the efficiency of propellers in the world. In 1912 the same testing apparatus was used by MIT student Frank W. Caldwell, who went on to become a leader in the development of propeller technology in both government and industry.
View Requa Gibson Propeller object record
More Early Propeller Designs
Solving the Control Challenge
There was no standard control system in early aircraft. A pilot had to control an airplane in three dimensions: pitch, roll, and yaw, which presented a major challenge.
- Roll: On the outer rear edge of each wing, the two ailerons move in opposite directions, up and down, decreasing lift on one wing while increasing it on the other. This causes the airplane to roll to the left or right. To turn the airplane, the pilot uses the ailerons to tilt the wings in the desired direction.
- Pitch: On the horizontal tail surface, the elevator tilts up or down, decreasing or increasing lift on the tail. This tilts the nose of the airplane up and down. This rotation is called pitch.
- Yaw: On the vertical tail fin, the rudder swivels from side to side, pushing the tail in a left or right direction. This rotation is called yaw. A pilot usually uses the rudder along with the ailerons to turn the airplane.
The Wright Model A. The wing warp positions on this aircraft (left wing edges bent up; right wing edges bent down) would make the aircraft roll to the left.
Wing Warping
Roll control presented a special problem on early aircraft (unlike pitch and yaw control that used movable surfaces such as elevators and rudders). The Wrights’ solution was a process called wing warping in which the outer trailing edges of the wing are literally bent upward or downward to control roll.
Ailerons
Other aircraft used ailerons—small hinged surfaces on the trailing edge of the wing— to achieve roll control, as on the 1911 Henry Farman aircraft to the right.
View from below of a Henry Farman 1911 Type de Course à 2 Place biplane in flight.
Are you in control?
Since there was no standard control system in earl aircraft, each manufacturer developed slightly different control systems. Learn about the control systems of three early aircraft from the Museum's collection.
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Wright Military Flyer
The Wright brothers used a system of two-hand levers to operate the controls on the Military Flyer. This was modified from the system used on their first aircraft.
- Pitch: Left lever moved back and forth operates elevator.
- Roll: Right lever moved back and forth operates wing warping.
- Yaw: Top of right lever rotates to operate rudder.
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Curtiss Headless Pusher
The distinguishing feature of the Curtiss system of control was the cradle with rails protruding on either side of the pilot. The pilot banked by leaning in the direction of the turn, moving the cradle, which operated the control surfaces. Curtiss also used ailerons, which were more efficient than the wing warping method used by many other designers.
- Pitch: Control stick moved back and forth operates elevator.
- Roll: Shoulder cradle moved side-to-side operates ailerons.
- Yaw: Control wheel rotated operates rudder.
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Blériot XI
The control system used by Louis Blériot is the same as that used by most aircraft today.
- Pitch: Control stick moved back and forth operates elevator.
- Roll: Control stick moved side-to-side operates wing warping.
- Yaw: Foot bar pivoted back and forth operates rudder.