There are many different types, classes and configurations of aircraft. This discussion is a very basic classification of aircraft as they pertain to airport design.
Propulsion systems fall into two basic categories; jet engine and piston engine.
In the Jet engine category there are:
One, Two, Three and Four engine aircraft. The single jet engine aircraft are mostly military and very limited general aviation. Most jet aircraft have either 2,3, or 4 engines. Six engine aircraft are limited to air cargo, large transport and military aircraft.
Jet engines can be classified into two general categories: turbojet and turbofan. A turbo jet consists of a compressor, combustion chamber, and turbine at the rear of the engine. A turbofan is a turbojet engine with the addition of large diameter blades in front of the compressor. These engines are used by most commercial aircraft and generally quieter than turbo jet engines.
Piston Engines are applied to all propeller driven aircraft powered by gasoline fed reciprocating engines. Most small general aviation aircraft use piston engines. The term Turbo Prop refers to propeller driven engines that are powered by turbine engines. Turbo-prop airplanes usually have one, two or four engines. In general aviation, an aircraft is often referred to as a twin when it has two engines, and single when it has one engine. Other aircraft classifications include:
Ultralights: these are aircraft that weigh less than 254 pounds, and maximum speed is 63mph and 5 gallons of fuel.
Lighter than air are hot air balloons and blimps
Experimental aircraft are usually uncertified small general aviation aircraft, homebuilts or kitplanes are aircraft built from kits
Fixed wing refer to aircraft
Rotorwing refer to helicopters
Short Take off and Landing (STOL): These aircraft are often used in remote and mountainous locations that are inaccessible by conventional aircraft. Typically these aircraft have low wing loading.
Tiltrotor : a hybrid aircraft that is a combination of a fixed wing and rotor wing aircraft