SP-367 Introduction to the Aerodynamics of Flight


- Appendix A -




General Definitions


any machine or weight-carrying device (whether lighter or heavier than air) designed to be supported by the air, either by bouyancy or by dynamic action


that class of aircraft being heavier than air and deriving it lift in flight chiefly from aerodynamic forces

airplane (aeroplane)

a subset of aerodynes, specifically, a mechanically driven fixed-wing aircraft, heavier than air, which is supported by the dynamic reaction of the air against its wings


the science that deals with the motion of air and other gaseous fluids, and of the forces acting on bodies when the bodies are in relative motion with respect to such fluids


that class of aircraft being lighter than air and deriving its support chiefly from buoyancy derived from aerostatic forces


a subset of aerostats, specifically, an aerostat provided with a propelling system and with a means of controlling the direction of motion


the science that deals with the equilibrium of gaseous fluid and of bodies immersed in them


the science and art of designing, constructing, and operating aircraft

Aircraft Types

Figure 160 presents sketches of the aircraft types defined herein.


airships (dirigibles)

nonrigid (blimp): a lighter-than-air craft having a gas bag, envelope, or skin that is not supported by any framework or reinforced by stiffening. Its shape is maintained by the internal pressure of the gas with which it is filled. semirigid (sometimes blimp): a dirigible having its main envelope reinforced by a keel but not having a completely rigid framework. rigid: a dirigible having several gas bags or cells enclosed in an envelope supported by an interior rigid framework structure.


an airplane designed to rise from and alight on either water or land


a rotary-wing aerodyne whose rotor is turned throughout its flight by air forces resulting from the motion of the craft through the air


a bag, usually spherical, made of silk or other light, tough, nonporous material filled with some gas which is lighter-than-air. It is an aerostat without a propelling system.


an airplane having two wings or supporting surfaces, one located above the other

boat, flying

type of airplane in which the fuselage (hull) is especially designed to provide flotation on water


an engineless airplane flown by being manipulated into air currents that keep it aloft


a type of rotary-wing aerodyne whose lift and forward thrust are derived from airfoils mechanically rotated about an approximately vertical axis


a light frame, usually of wood, covered with paper or cloth and designed to be flown in the wind at the end of a string

lifting body

an aerodyne which derives most or all of its lift in flight from the shape of its fuselage, the wings being essentially nonexistent


an airplane having but one wing or supporting surface


a type of aircraft achieving its chief support and propulsion from the bird-like flapping of its wings


cloth device, consisting of a canopy and suspension lines, which basically produces a drag force to retard the descent of a falling body

[183] paraglider

a flexible-winged, kite-like vehicle designed for use in a recovery system for launch vehicles

pusher airplane

an airplane with the propeller or propellers aft of the main supporting surfaces

rotary-wing aircraft

a type of aerodyne which is supported in the air wholly or in part by wings or blades rotating about a substantially vertical axis

tailless airplane

an airplane in which the devices used to obtain stability and control are incorporated in the wing

tractor airplane

an airplane with the propeller or propellers forward of the main supporting surfaces


short take-off and landing airplane


vertical take-off and landing airplane


an airplane which has both STOL and VTOL capabilities

[183-186] Figure 160.- Examples of aircraft types.

Nonrigid airship

Hot air balloon

Rigid airship




Amphibian (Grumman SA-16A Albatross)

Grumman SA-16A Albatross plane



Biplane (Bristol F2B)

Bristol F2B plane

Flying boat (Shin Meiwa PX-S)

Shin Meiwa PX-S plane

Glider (Schweizer 1-23)

Schweizer 1-23 glider

Helicopter (Sikorsky CH-3C)

Sikorsky CH-3C helicopter



Lifting body (HL-10)

HL-10 lifting body plane

Monoplane (Piper Arrow)

Piper Arrow monoplane

Flapping wing ornithopter

Flapping wing ornithopter


Three type of parachutes,cross,modified ring-sail,and disk-gap-band



Pusher airplane (XB-42)

XB-42 pusher airplane

Rotary-wing aircraft (Bell Jet Ranger)

Bell Jet Ranger rotary-wing aircraft

Tailless airplane (Avro 707B)

Avro 707B tail-less airplane

Tailless aiplane (YB-49)

YB-49 tail-less airplane

Tractor airplane (Boeing 377 Stratocruiser)

Boeing 377 Stratocruiser tractor airplane

STOL- Short Take-off and landing airplane (DHC-6 Twin Otter)

DHC-6 Twin Otter Short Take-off and Landing airplane

VTOL - Vertical take-off and landing airplane (P1227 Harrier)

P1227 Harrier Vertical Take-off and Landing airplane

V/STOL airplane (X-22A)

X-22A V/STOL airplane