Figure 1: Original Drawing of Da-Vinci's Helicopter and a Modern Day Computer Model [3], [9]

Sean SummersWRIT 340, Warford

Illumin Article

The Helicopter: A 400 Year History of Scientific Innovation

Throughout history, one creation that has seemed to go relatively unnoticed is the

helicopter. Undervalued and understudied, the helicopter is a facet of the aerospace industry

that has always been overshadowed by the more well-known creation, the airplane. When did

this wacky invention come about? What useful purposes did it actually serve? Its 400 year

history is a tale of scientific innovation, engineering creativity, and the pursuit of the unknown.

1 THE HUMBLE BEGINNING

The helicopter has a history that stretches back centuries. Many historians believe that the

idea of a helicopter originated from Milan, Italy, sometime in the 1480’s [1]. Its creator was the

philosopher, artist, and scientist, Leonardo Da-Vinci. Da-Vinci had a fascination for inventing

flying machines. Many of his machines modeled the flight characteristics of birds, with a

flapping motion and wings, called

“ornithopters”; however, buried in his

hundreds of drawings was one creation

that looked nothing like the rest. It was

a machine that had a screw-like linen

wing structure, which is now

commonly known as the aerial screw, with a wooden standing platform on the bottom, seen in

Figure 1. Da-Vinci proposed that if the spiral was spun fast enough, the machine would

Sean SummersWRIT 340, Warford

Illumin Articleessentially use the momentum of the air it forced downward to lift itself. The idea of the

helicopter was born. Though it was never constructed, many models exist today.

Da-Vinci’s idea was a radical and creative start; yet, it did have a few flaws. Firstly, the

contraption allowed the floor underneath the operators to move. This meant that only half of the

power generated by the users would be transmitted to moving the air, while the other half moved

the ground underneath them; this is because of Newton’s First Law of Physics, for every action

there is an equal and opposite reaction. What would later become a concern to engineers, this

phenomenon was called torque reaction. The second flaw was that the screw design requires lots

of power in order to take flight. As of today, no full size replica has actually been flown.

Unfortunately, the helicopter wouldn’t see progress for another 270 years.

2 THE INDUSTRIAL AGE

It wasn’t until the Industrial Revolution that the interest in rotary winged aircraft was

sparked again. New materials, like metals and plastics, allowed for lighter and more intricate

designs. Da Vinci’s idea of an aerial screw had been

scrapped and was replaced by a set of rotating wings,

called rotors. During the 1700’s, engineers and scientists

used spring powered systems in an attempt to master the

physics of rotary winged aircraft, countering the torque

reaction, as well as keeping the body steady. One such

invention is presented in Figure 2. Dating back to 1784,

this invention took advantage of a bowdrill system

attached to two rotors of turkey feathers that rotated in

Figure 2: A drawing of Launoy and Bienvenu’s dual rotor model [3]

Sean SummersWRIT 340, Warford

Illumin Articleopposite directions [1]. It was found that two rotors spinning in opposite directions eliminated

their torque reactions, allowing the body to which they were attached to remain steady and in

flight. The mechanisms became larger and larger, until the invention of the steam engine brought

about the era of full sized crafts. During the 1800’s, the rotary winged aircraft slowly began to

evolve and more closely resemble what we consider today to be a helicopter. In fact, the word

helicopter was invented during this time, in 1863, when Viscount Gustave de Ponton d'Amécourt

from France combined the Greek words helicon and pteron, meaning “spiral” and “wing” [1].

Through decades of bulky and awkward inventions, some large contraptions were able to attain

flight by the end of the 19th century, but none with a pilot. It wasn’t until the 1900’s when

helicopters gained their success.

3 SUCCESS

The first manned rotary winged vehicle to take

flight, and what is widely considered to be the first ever

helicopter, was flown on November 3, 1907 by French

engineer and bicycle maker Paul Cornu [2]. The

aircraft, seen in Figure 3, utilized two vertical rotors to

compensate for torque reaction and ran on a 24

horsepower gasoline engine [3]. However, the flight was only for thirty seconds at one foot off

the ground. After this success, development of the helicopter really took off. Only four years

later, the first design of a main vertical rotor and a horizontal tail rotor was published (the design

many helicopters are based off of today) [1]. Until this point in history, the full potential of a

Figure 3: The Cornu Helicopter (1907), what is considered to be the first helicopter [7]

Sean SummersWRIT 340, Warford

Illumin Articlevertical flight aircraft had never been realized. Engineers had only pursued the idea of a

helicopter for their pure love of science and technology. However, what really got helicopters off

the ground had a much more malevolent intention.

4 THE MILITARY AGE

Soon after the first helicopter was flown, World War I began, which further fueled the

research of rotary winged aircrafts. The US military was in need of a vehicle to replace their

balloon surveillance craft, and they were looking to the helicopter as a solution. Furthermore, the

quality and quantity of building materials, as well as engine technology, were rapidly improving

during this time due to the war effort. Though much funding was directed toward the study of

helicopters, no successful craft was made during the war. The US Army didn’t have their first

helicopter until 1922; it was called the Jerome-de Bothezat Flying Octopus [1]. Though it was

much improved from Cornu’s helicopter in 1907, and could sustain flight, it still lacked

maneuverability and altitude. From the 1920’s to the 1930’s, fuselages were added to

helicopters, and the design of a tail rotor was catching on; the tail rotor was a new adaptation to

counter torque reaction. In just a mere 20 years, the first production helicopter was born.

The year was 1939, and Igor Sikorsky, who

would later be known as the father of helicopters,

had invented the VS-300, the world’s first fully

controllable helicopter, seen in Figure 5. It utilized

the iconic design of a main rotor and tail, and

incorporated a powerful 75 horsepower engine [2]. It

also was fitted with pontoons, making it the first Figure 4: Sikorsky's VS-300 (1939) [2]

Sean SummersWRIT 340, Warford

Illumin Articleamphibious helicopter as well [1]. The race was now on for the best military helicopter. In 1940,

Germany released the Flettner FL 282 Kolibri, which was the first helicopter to be used in

combat [1]. It looked much like Sikorsky’s VS-300 and served many roles, like rescue, artillery

spotting, and submarine escort. Just three years later,

Sikorsky released the R-4, shown in Figure 5, the

world’s first helicopter to be mass produced [1]; in

1943, as World War II was underway, the US Army

jumped on board, ordering 29 prototypes to be built.

The realization of the helicopter’s full potential was

now catching on. In 1944, the first combat rescue via

helicopter was attempted by U.S. Army Lieutenant

Carter Harman in the China-Burma-India theater. He was successful in rescuing three British

soldiers. The popularity of the R-4 spread worldwide, as the Royal Air Force had begun

purchasing their own.

In just ten years, the helicopter had become a highly desired commodity across the globe. It

was desired purely for its military applications, and by the end of 1950, fully functioning

vehicles were seen in Germany, Canada, the USSR, Britain, France, and the United States. The

aviation industry was booming and numerous companies, some of which are still in operation

today, were being born: Sikorsky (founded by Igor Sikorsky), Lockheed, Canadair, Mil, and

Hughes [3]. The 1950’s saw the invention of the turbine powered helicopter, further powering

the rotorcrafts and enhancing their flight capabilities. Their ability to land in hard to reach areas

and hover for long durations of time served many purposes outside the military sector. Aircraft

could now carry more than one passenger, and fly at speeds up to 190 miles per hour [3].

Figure 5: Sikorsky's R-4 (1944) [8]

Sean SummersWRIT 340, Warford

Illumin ArticleThe Vietnam War saw the first fully incorporated

military action of the helicopter with the Bell UH-1

Iroquois (nicknamed the “Huey”). The iconic

helicopter, shown in Figure 6, was used in a wide array

of missions, from medical evacuation to bombing runs.

However, the helicopter was not yet perfect. During its

rise to fame, weapons technology had also evolved;

heavy gun fire and missiles could easily take down the

aircraft, and in total 3,305 of the 7,013 UH-1s that served in Vietnam were destroyed [4]. In total

1,074 Huey pilots were killed, along with 1,103 other crew members. The need for an evasive

military helicopter was evident [4].

The rise of computer technology was the last development for the helicopter. Computer

aided flight controls, night vision, autonomous engine adjustment, and advanced weaponry, all

made the helicopter a serious threat from above, as well as a versatile vehicle for other non-

military groups. Nearly all modern societies have uses for helicopters: search and rescue, fire

control, police enforcement, news footage, an even construction.

5 TODAY

The helicopters of today are extremely advanced, highly utilized pieces of machinery. Their

uses range from medical evacuation, search and rescue, news reporting, construction, wildlife

conservation, and military action. Modern helicopters can reach speeds upwards of 250 miles per

hour and can lift payloads of 22 tons [3]. Even more experimental aircrafts are combining the

Figure 4: The Bell UH-1 Iroquois "Huey" (1965), serving in Vietnam [8]

Sean SummersWRIT 340, Warford

Illumin Articlecharacteristics of airplanes and helicopters, bringing about a new era in aviation that further

pushes the envelope of rotary wing engineering. The idea is to combine the long range and fast

flight abilities of the airplane with the vertical takeoff and maneuverability of a helicopter. One

such aircraft that has done just that is the Bell Boeing V-22 Osprey, shown in Figure 7 [1].

Known as a “tiltrotor” aircraft, this vehicle takes off with two vertical rotors, but transitions to

airplane flight by tilting its rotors forward to become

propellers. It has already seen its debut in war efforts

in Afghanistan and Iraq and is continuing to prove

its mission capabilities. Another development in

helicopter design is the incorporation of stealth

technology. The most current stealth helicopter is the HAL Light Combat Helicopter [5], which

features radar absorbent materials, radar deflecting geometries, and noise reduction. The other

area of helicopter innovation involves small remote control helicopters that incorporate three or

more rotors. Popularly known as “quadrotors,” these small devices are extremely quick and

nimble, performing aerial acrobatics never seen before. These small devices can also send video

feeds to their controllers. However, unmanned miniature helicopters like these are more than just

a hobby for some; they are currently being applied in military surveillance and search and rescue

missions.

6 THE FUTURE

The future of helicopter aircrafts is far from certain. With technology developing at such a

rapid rate, little is known of the capabilities or possible advances that the aerospace industry

might see. In a video produced by the US Army titled Aviation 2050 Vision – Technology for

Tactics, a sci-fi like future is projected for rotorcraft. The video claims, "Future vertical lift

Figure 5: Bell-Boeing V-22 Osprey (2005), transitioning between vertical and horizontal flight

[11]

Sean SummersWRIT 340, Warford

Illumin Articleaircraft will fly further, faster, and perform in a wider range of environmental conditions while

carrying heavier payloads. Aircraft may be manned or unmanned. Flight operations will be

automated, and the pilot will assume more of a

mission commander role." It is very likely that

the future will see the incorporation of

unmanned, jet propelled helicopters, much like

the one presented in Figure 8. Larger aircrafts

might incorporate more rotors, as seen in the

video, to add larger payload capacity.

The technology and engineering of helicopters has seen a radical change over its lifetime.

Similarly to how Da Vinci’s idea was much unlike the helicopters of the 1900’s, our ideas of

helicopters today may be much different than what the future holds. It is likely the current trend

of innovation may even lead to solutions we don’t even know we need yet.

7 REFERENCES

Figure 6: Aviation 2050 Vision - Technology for Tactics (Video) [10]

Sean SummersWRIT 340, Warford

Illumin Article

[1] "Helicopter History Site," [Online]. Available: http://www.helis.com/pioneers/. [Accessed 6 Feb 2014].

[2] J. Rumerman, "U.S. Centennial of Flight Commission," [Online]. Available: http://www.centennialofflight.net/essay/Rotary/early_20th_century/HE2.htm. [Accessed 4 Feb 2014].

[3] "Aerospaceweb.org," [Online]. Available: http://www.aerospaceweb.org/design/helicopter/history.shtml. [Accessed 29 Jan 2014].

[4] "Vietnam Helicopter Pilots Association," [Online]. Available: http://www.vhpa.org/heliloss.pdf.

[5] "Defense Aviation," [Online]. Available: http://www.defenceaviation.com/2010/04/indias-light-combat-helicopter.html. [Accessed 10 February 2014].

[6] E. Teale, "Planes That Go Straight Up," Popular Science, vol. 126, no. 3, 1935.

[7] "Cornu Helicopter," [Online]. Available: http://projetcornu.free.fr/img/PhotoAccueilModifiee.JPG.

[8] R. Lemos, "The Helictoper: A Hundred Years of Hovering," WIRED, 12 November 2007. [Online]. Available: http://www.wired.com/science/discoveries/multimedia/2007/11/gallery_helicopter?slide=2&slideView=2. [Accessed 11 February 2014].

[9] "All Spectrum Electronics," [Online]. Available: http://www.allspectrum.com/store/product_thumb.php?img=images/EDU-61002.gif&w=88&h=80. [Accessed 11 February 2014].

[10] Aviation 2050 Vision - Technology for Tactics. [Film]. United States: United States Army, 2013.

[11] "Edwards Airforce Base," 26 April 2005. [Online]. Available: http://upload.wikimedia.org/wikipedia/en/thumb/3/34/Osprey_firing_flares.jpg/120px-Osprey_firing_flares.jpg. [Accessed 4 February 2014].