A number of different types of air transportation exist, both commercially and privately. Some of these types have been developed over the course of decades or even centuries to meet the needs of modern humans. Each different type is unique in the way it achieves flight, the speed it travels and the sustainability of its voyage. Many of the inventions have developed into large scale industries. However, some methods are still in their infancy, or they merely represent a small niche within the world of flight.
Hot Air Balloons
The first successful type of air transportation that carried humans was the hot air balloon. The Montgolfier brothers developed the idea of designing a large bag or balloon that held hot air in the late 1700s. Passengers and the heat source were placed in a gondola or wicker basket underneath the balloon. Since hot air rises, the balloon flew according to the direction of the wind. By cooling the balloon's temperature, the passengers safely floated back to earth. Today's hot air balloons use almost the exact same technology, however, they are able to design the balloons into nearly any shape imaginable.
An offshoot of the hot air balloon is the blimp. Blimps have been around since the end of the 19th century and were first used as scouting tools by various militaries. The technology has developed into a convenient and cost-effective way to travel and advertise products. To float, blimps use hot air and large fans attached to the gondola underneath. They can be deflated for storage or transportation and inflated cheaply when service is needed. Arguably, the Goodyear Blimp is the most famous of this mode of transportation, seen at sporting games and events around the world.
Zeppelins were built in the early 20th century, based on designs by Count Ferdinand von Zeppelin. Visually, zeppelins appear very much like blimps. However, they differ on two key points: zeppelins have a metal skeleton with a rigid covering, and they are filled with hydrogen. These two elements made zeppelins much larger than blimps and capable of sustaining long-distance flights. During World War I, they were introduced as the first flying machine to practice bombing runs. Through the successive decades, zeppelins were used in the first commercial airline service, ferrying passengers from Germany to the Americas. Unfortunately, the zeppelin industry was destroyed by the public outcry from the 1937 Hindenburg disaster, when a zeppelin exploded over New Jersey, killing 35 people.
The fixed-wing aircraft is the most popular form of air transportation available. According to FlightAware, a flight tracking organization, there are 49,315 commercial flights around the world each day that use fixed-wing aircraft. Nearly 1.1 billion people are flown each year. Fixed-wing aircraft are distinguishable from other types of air transportation in that they achieve lift through forward motion. A long runway is needed for the vehicles to achieve enough velocity to become airborne. Airplanes use a propeller or jet engine to power the aircraft, and the wings act as a stabilizer for keeping the vehicle in the air.
The first design for functional fixed-wing aircraft dates back to the 1800s. Most of these designs were models that were not large enough to hold passengers. The first official sustained flight was performed by the Wright Brothers on Dec. 17, 1903. Over the next decade, advances in the technology continued. World War I became the first full-scale testing ground for fixed-wing aircraft. Thousands of planes were built for the purpose of spying, bombing and fighting. By the time the war ended, aviation had become a science. Following the war, larger passenger planes were produced, and ultimately, the jet engine was designed, making way for one of the fastest modes of transportation in the world. Airplanes are used by militaries and civilian agencies around the world. They have been incorporated with luxurious facilities in the case of passenger planes and extensive weapons systems for military use.
With the success of the fixed-wing aircraft, engineers and technicians looked for a way to make the general principles of airplanes, sustained and fast flight, more efficient. The goal was to develop a flying vehicle that could take off from a sitting position and carry people to another location. This invention is the helicopter. Helicopters are propelled using horizontal rotors consisting of two or more blades. These blades rotate around the top of the machine, and achieve lift, pulling the body of the helicopter along. Designs for the helicopter had been conceived as far back as the 1480s, with Leonard da Vinci. However, it wasn't until the early 1900s that individuals created working models. The post-war era saw the birth of the helicopter industry. However, most models can only carry four to six people, limiting its commercial use. The primary applications for helicopters are in the military, law enforcement, medical, news or fire control sectors.
Personal Air Transportation
The mid-1900s saw the birth of a new type of air transportation: the personal vehicle. Individuals invented autogyro, gliders and jet packs for the purpose of transporting a single person from one place to another. Some of the earliest styles of helicopters were single-seat vehicles. This was the inspiration for the autogyro. The autogyro uses elements from both fixed-wing and rotary aircraft in order to fly. The lift is supplied by a rotor positioned on the mast. The stability and power for flight is achieved by a rear propeller and a set of wings. Gliders use no power to control flight. They simply use the stability of fixed-wings to soar through the air. The controller can move flaps on the wings in order to hit updrafts that keep the vehicle in the air. A jet pack is a device that is generally strapped to the back and releases a powerful blast of gases that allow the user to fly. These devices are very inefficient, as most models can only contain enough gases to sustain flight for a few minutes.
Perhaps the most advanced form of air transportation comes in the form of rockets. Rockets use thrust obtained via the chemical reaction of a fluid that is ejected at high velocities from the vehicle. The force from the explosion within the vehicle's combustion chamber forces gases out of the tail of the rocket, pushing the vehicle to extremely high speeds. The principle is based on inertia, in that every action has an equal and opposite reaction. Rockets have been used at least since the 13th century for small-scale military applications and recreational displays. However, the first full-scale implementation was during World War II with Germany's V-2 rockets and various rocket-powered aircraft. The post-war era saw the rocket implemented as a mode of transportation that allowed for suborbital and orbital flights in the upper atmosphere. These vehicles are used for both public and private enterprises.