The Boeing 707 is a four-engine commercial passenger jet airliner developed by Boeing in the early 1950s. Its name is most commonly pronounced as "Seven Oh Seven". Boeing delivered a total of 1,010 Boeing 707s including a smaller, faster model of the aircraft that was marketed as the Boeing 720.

Although it was not the first commercial jet in service, the 707 was among the first to be commercially successful. Dominating passenger air transport in the 1960s, and remaining common throughout the 1970s, the 707 is generally credited with ushering in the Jet Age.[3][4] It established Boeing as one of the largest makers of passenger aircraft, and led to the later series of aircraft with "7x7" designations.

No hybrid aircraft design has ever been developed past the initial experimental stages despite many such designs having been proposed over the years, though recent advances may indicate that the technology has matured.

In 1905, Alberto Santos-Dumont made what is likely the first attempt at a hybrid aircraft. His Number 14 combined an airship envelope with an airplane frame. At that time, Santos-Dumont was the world's most accomplished aviator. All of his previous flights had been made in purely aerostatically lifted airships. The Number 14 proved unworkable. Later, Santos-Dumont would remove the envelope and successfully use the recristened 14-bis (meaning "14-again") to make the first public flight of any heavier-than-air aircraft in the world.

A propeller or airscrew comprises a set of small, wing-like aerofoils set around a central hub which spins on an axis aligned in the direction of travel. Spinning the propeller creates aerodynamic lift, or thrust, in a forward direction.

A tractor design mounts the propeller in front of the power source, while a pusher design mounts it behind. Although the pusher design allows cleaner airflow over the wing, tractor configuration is more common because it allows cleaner airflow to the propeller and provides a better weight distribution.

Early designers considered both monoplane and biplane designs. However, the weakness of the materials and design techniques available required these designers to place great effort into making wings capable to withstanding the required loads. A biplane (having the characteristics of a box girder) can be made lighter for a given strength requirement, and was therefore a more common choice.

Most successful early aircraft were biplanes, in spite of considerable early experimentation with monoplanes, triplanes and even a quadraplanes. During the period (~1914 to 1925) almost all aircraft were biplanes.

Aircraft built with two main wings (or three in a triplane) can usually lift up to 20 percent more than can a similarly sized monoplane of similar wingspan, which tends to afford greater maneuverability. The struts and wire bracing of a typical biplane form a box girder that permits a light but very strong wing structure.

On the other hand there are many disadvantages to the configuration. Each wing negatively interferes with the aerodynamics of the other. For a given wing area the biplane produces more drag and less lift than a monoplane, but this effect can be slightly reduced by placing one wing forward of the other though NACA research into this suggests that the reduction of drag is minimal.

A biplane is a fixed-wing aircraft with two main wings. The Wright brothers' Wright Flyer used a biplane design, as did most aircraft in the early years of aviation. While a biplane wing structure has a structural advantage, it produces more drag than a similar monoplane wing. Improved structural techniques and materials and the need for greater speed made the biplane configuration obsolete for most purposes by the late 1930s.

General aviation is a catch-all covering other kinds of private and commercial use, and involving a wide range of aircraft types such as business jets (bizjets), trainers, homebuilt, aerobatic types, racers, gliders, warbirds, firefighters, medical transports, and cargo transports, to name a few. The vast majority of aircraft today are general aviation types.

Within general aviation, there is a further distinction between private aviation (where the pilot is not paid for time or expenses) and commercial aviation (where the pilot is paid by a client or employer). The aircraft used in private aviation are usually light passenger, business, or recreational types, and are usually owned or rented by the pilot.