From Ornithopters to Helicopters: A Brief History of Aviation Milestones and Innovations

Over the ages, people have been fascinated by flight. Early designers were inspired by the natural fluidity of bird flight to replicate nature and create vehicle designs that could lift humans above the constraints of the earth's surface. The fascination of humans with birds as the basis of flying is well depicted in both Leonard da Vinci’s (Italian artist, architect, scientist, and engineer) sketches and sayings.    

“A bird is an instrument working according to mathematical law, an instrument which is within the capacity of man to reproduce with all its movements.”

Leonard da Vinci

From the earliest flapping wings to modern flying aircraft, aviation history has come a long way. This article provides a brief overview of the significant milestones in the history of aviation, from the first attempts at human flight with Ornithopters to the development of balloons, dirigibles, gliders, powered flight, jet aircraft, and helicopters. The article covers notable inventors and their achievements, such as Leonardo da Vinci, the Wright brothers, and Igor Sikorsky, as well as key innovations, including the use of hot air and hydrogen in balloons, the development of jet engines, and the creation of practical helicopters

Ornithopters

Leonard da Vinci – Flying Machine. Credit: Google

Ornithopters were the first attempt by humans to fly. Being fascinated by birds and their flapping wings, people fashioned artificial wings and flapped them with their arms. But it was proved unsuccessful as flapping requires continuous and a lot of power. Afterwards, mechanical mechanisms were used to flap the wings up and down. This resulted in vehicles known as Ornithopters. The great Italian artist, architect, scientist, and engineer Leonardo da Vinci (1452–1519) devoted much of his time to flight. His manuscripts contained some 160 pages of descriptions and sketches of flying machines.

Balloons

Montgolfier brothers – Hot Air Balloon. Credit: Google 

The balloon flight was pioneered by two French brothers some 250 years after Leonardo’s work. They use the concept of rising hot air to achieve flight. The first hot balloon was risen up to 305 meters (1000 ft.) on 25 April 1783. But as soon as the hot air cooled down, balloons began to descend. Therefore, longer duration and high altitude was the barrier to hot air balloon flight.

With the advancement in balloon design, hot air was replaced by hydrogen. Being lighter than air, hydrogen rises in ambient air. This allowed balloons to rise higher and the flight was also independent of the temperature difference of hydrogen with ambient air. Further, hydrogen balloons were equipped with sails and rudders to achieve controlled flight. Professor Jacques Alexandre César Charles was the first to successfully demonstrate a hydrogen balloon on 27 August 1783. Charles and his assistant made a 43 km (27 mi) free flight from the garden of the Tuileries, Paris, on 1 December 1783.

Dirigibles

Hindenburg Zeppelin. Credit: Google

Dirigibles (also called zeppelins) were elongated bags filled with gas. They were the mean of controlled and powered flight and thus fitted with engines, propellers and rudders. The major challenge with dirigibles was to maintain their elongated aerodynamic shape for efficient steering when bags were only partially filled with gas. The first light and rigid-shaped dirigible flight were carried out by Luftschiff Zeppelin (LZ-1) on 2 July 1900.  

Gliders

George Cayley’s glider. Credit: Google

Gliders were light aircraft equipped with fixed wings to generate lift and were able to fly without the means of the power plant. Glider configuration was initiated by Sir George Cayley in 1799.  His aircraft configuration consisted of fixed wings, peddles, and horizontal and vertical stabilizers at the tail unit. In 1853, he came up with a full-size glider. Another notable figure in gliding flight was Otto Lilienthal, who made 2,000 successful gliding flights before dying in a gliding accident.

Powered Flight

Wright Brothers' Flayer 1. Credit: Google

The first controlled, powered and heavier-than-air flight was achieved by the Wright brothers. They flew their first aeroplane, Flayer 1 on 17 December 1903 which was equipped with a 12 hp engine and the flight covered a distance of 37 m (120 feet) in 12 seconds. Their second plane in 1906 managed to cover a distance of 4.45 km and the flight lasted for more than 5 minutes. Key to their success was the slight warping of wings that provided means of controllability to aircraft.  

Jet Aircraft

German Focke-Wulf Fw 61. Credit: Google

Firstly, the jet engine was designed individually in both Brittan and Germany. Though the first aircraft powered by a jet engine was German Heinkel He 178, manufactured in the late 1930s. The first jet aircraft in service was the British Gloster Meteor. Which was further led by the German Messerschmitt Me-262, which could fly at a maximum speed of 870 km/h.

Helicopters 

German Focke-Wulf Fw 61. Credit: Google

The German Focke-Wulf Fw 61 was the first practical helicopter, flown in 1936 as the highlight of an indoor show in Berlin. Later, in 1939, Igor Sikorsky designed, built, and flew the experimental helicopter Vought Sikorsky VS-300 in the United States. The VS-300 was equipped with a single main rotor for lift and a smaller vertical rotor mounted on the tail to counteract torque. This rotor arrangement made Sikorsky able to achieve controllability.