Controlling the flight

1. The 1880s became a period of intense study, characterized by the "gentleman scientists" who represented most research efforts until the 20th century. Starting in the 1880s advances were made in construction that led to the first truly practical gliders. Three people in particular were active: Otto Lilienthal, Percy Pilcher and Octave Chanute. One of the first modern gliders appears to have been built by John J. Montgomery; it flew one flight outside of San Diego on August 28, 1883. It was not until many years later that his efforts became well known. Another hang-glider had been constructed by Wilhelm Kress as early as 1877 near Vienna.

2. Otto Lilienthal of Germany duplicated Wenham's work and greatly expanded on it in 1874, publishing his research in 1889. He also produced a series of ever-better gliders, and starting in 1891 was able to make flights of 25 meters or more routinely. He rigorously documented his work, including photographs, and for this reason is one of the best known of the early pioneers. He also promoted the idea of "jumping before you fly", suggesting that researchers should start with gliders and work their way up, instead of simply designing a powered machine on paper and hoping it would work. His type of aircraft is now known as a hang glider.

By the time of his death in 1896 he had made 2500 flights of up to 250 meters on a number of designs, when a gust of wind caused him to fall from a height of roughly 50 feet (15 m). He died the next day. Lilienthal had been working on small engines suitable for powering his designs at the time of his death.

3. Australian Lawrence Hargrave invented the box kite and dedicated his life to constructing flying machines. In the 1880s he experimented with monoplane models and by 1889 Hargrave had constructed a rotary airplane engine, driven by compressed air.

4. Picking up where Lilienthal left off, Octave Chanute took up aircraft design after an early retirement, and funded the development of several gliders. In the summer of 1896 his team flew several of their designs many times at Miller Beach, Indiana, eventually deciding that the best was a biplane design that looks surprisingly modern. Like Lilienthal, he heavily documented his work while photographing it, and was busy corresponding with like-minded hobbyists around the world. Chanute was particularly interested in solving the problem of aerodynamic instability of the aircraft in flight, which birds compensate for by instant corrections, but which humans would have to address either with stabilizing and control surfaces or by moving the center of gravity of the aircraft, as Lilienthal did. The most disconcerting problem was longitudinal instability (divergence), because as the angle of attack of a wing increased, the center of pressure moved forward and made the angle increase more. Without immediate correction, the craft would pitch up and stall. Much more difficult to understand was the mixing of lateral/directional stability and control.

5. Throughout this period, a number of attempts were made to produce a true powered aircraft. However the majority of these efforts were doomed to failure, being designed by ill-informed amateurs who did not have a full understanding of the problems being discussed by Lilienthal and Chanute.

6. In 1884, Alexander Mozhaysky's monoplane design made what is now considered to be a powered take off assisted by the use of ramp, flying between 60–100 ft (20–30 m) near Krasnoye Selo, Russia.

7. In France Clément Ader built the steam-powered Eole and may have made a 50-meter flight near Paris in 1890, which would be the first self-propelled "long distance" flight in history. Ader then worked on a larger design which took five years to build. In a test for the French military, the Avion III failed to fly and, caught by a gust of wind, was seriously damaged. Ader's later claims to have achieved a flight of 300 metres were later proved false. Sir Hiram Maxim made a number of experiments in Britain, eventually building an enormous 7,000 pounds (3,200 kg) machine with a wingspan of 105 feet (32 m), powered by two advanced lightweight steam engines which delivered 180 hp (134 kW) each. Maxim built it to study the basic problems of construction, lift and propulsion. He used a 1,800 feet (550 m) track with a second set of restraining rails for test runs. After a number of tests, on 31 July 1894 he started a series of runs at increasing power settings. The first two were successful, with the craft lifting off the track. In the afternoon the crew of three fired the boilers to full power, and after reaching a speed of over 42 mph (68 km/h) about 600 feet (180 m) down the track the machine produced so much lift it broke one of restraining rails and crashed after flying at a low altitudes for about 200 feet (61 m). Having spent around £30,000, and unwilling to spend more, he abandoned these experiments, only resuming his work in the 20th century, when he tested a number of smaller designs powered by gasoline engines.