Categories and classification of Airplanes

Lighter than air

Lighter than air aerostats: hot air balloons and airships. Aerostats use buoyancy to float in the air in much the same manner as ships float on the water. In particular, these aircraft use a relatively low density gas such as helium, hydrogen or heated air, to displace the air around the craft. The distinction between a balloon and an airship is that an airship has some means of controlling both its forward motion and steering itself, while balloons are carried along with the wind.

Heavier than air – aerodynes

Heavier-than-air aircraft must find some way to push air or gas downwards, so that a reaction occurs (by Newton's laws of motion) to push the aircraft upwards. This dynamic movement through the air is the origin of the term aerodyne. There are two ways to produce dynamic upthrust: aerodynamic lift, and powered lift in the form of engine thrust.

Aerodynamic lift is the most common, with fixed-wing aircraft being kept in the air by the forward movement of wings, and rotorcraft by spinning wing-shaped rotors sometimes called rotary wings. To fly, air must flow over the wing and generate lift. A flexible wing is a wing made of fabric or thin sheet material, often stretched over a rigid frame. With powered lift, the aircraft directs its engine thrust vertically downwards.

The initialism VTOL (vertical take off and landing) is applied to aircraft that can take off and land vertically. Most are rotorcraft. Similarly, STOL stands for short take off and landing. Some VTOL aircraft often operate in a short take off/vertical landing mode known as STOVL.

A pure rocket is not usually regarded as an aerodyne, because it does not depend on the air for its lift (and can even fly into space); however, many aerodynamic lift vehicles have been powered or assisted by rocket motors. Rocket-powered missiles which obtain aerodynamic lift at very high speed due to airflow over their bodies, are a marginal case.

There are several ways to classify aircraft. Below, we describe classifications by design, propulsion and usage.

1-By Design- Fixed wing, flying wing, Lifting body, Rotorcraft,

2-By Propulsion- Unpowered-gliders, balloons and Kites Powered- Propeller used- Tractor, pusher and contra-prop type Jet engine (airbreathing)- Turbojet, turbofan, ramjet, pulsejet, scramjet. Rocket powered aircraft.3- By usage- Military type- Combat (fighters and bombers type) and non-combat type aircraft. Civil type- Commercial (passanger and cargo) and general aviation (business jet, homebuilt, aerobatic types, racers, gliders, firefighters, medical transports)4- By speeds- low subsonic, high subsonic, transonic, supersonic, hypersonic types.