aviation Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes airplane, fixed-wing and helicopter, rotary-wing types, morphable wings, wing-less lifting bodies, as well as aerostat, lighter- ...

, coordinated flight of an

aircraft An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...

is flight without

sideslip A slip is an aerodynamic state where an aircraft is moving ''somewhat'' sideways as well as forward relative to the oncoming airflow or relative wind. In other words, for a conventional aircraft, the nose will be pointing in the opposite directio ...

.Clancy, L.J., ''Aerodynamics'', Section 14.6 When an aircraft is flying with zero sideslip a turn and bank indicator installed on the aircraft's instrument panel usually shows the ball in the center of the spirit level. The occupants perceive no lateral acceleration of the aircraft and their weight to be acting straight downward into their seats. Particular care to maintain coordinated flight is required by the pilot when entering and leaving turns.

Transport Canada Transport Canada (french: Transports Canada) is the department within the Government of Canada responsible for developing regulations, policies and services of road, rail, marine and air transportation in Canada. It is part of the Transporta ...

: ''Flight Training Manual'', 4th edition, page 9. Gage Publishing, 1994.

Advantages

Coordinated flight is usually preferred over uncoordinated flight for the following reasons: *it is more comfortable for the occupants *it minimises the drag force on the aircraft *it causes fuel to be drawn equally from tanks in both wings *it minimises the risk of entering a

spin Spin or spinning most often refers to: * Spinning (textiles), the creation of yarn or thread by twisting fibers together, traditionally by hand spinning * Spin, the rotation of an object around a central axis * Spin (propaganda), an intentionally ...

Instrumentation

Airplane An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad ...

s and

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attribu ...

s are usually equipped with a turn and bank indicator to provide their pilots with a continuous display of the lateral balance of their aircraft so the pilots can ensure coordinated flight. Glider pilots attach a piece of coloured string to the outside of the canopy to sense the sideslip angle and assist in maintaining coordinated flight.

Axes of rotation

An airplane has three axes of rotation: #Pitch – in which the nose of the airplane moves up or down. This is typically controlled by the

elevator An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They ...

at the rear of the airplane. #Yaw – in which the nose of the airplane moves left or right. This is typically controlled by the

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adve ...

at the rear of the airplane. #Roll (bank) – in which one wing of the airplane moves up and the other moves down. This is typically controlled by

aileron An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

s on the wings of the airplane. Coordinated flight requires the pilot to use pitch, roll and yaw control simultaneously. See also

flight dynamics Flight dynamics in aviation and spacecraft, is the study of the performance, stability, and control of vehicles flying through the air or in outer space. It is concerned with how forces acting on the vehicle determine its velocity and attitude ...

Coordinating the turn

If the pilot were to use only the

to initiate a turn in the air, the airplane would tend to "skid" to the outside of the turn. Clancy, L.J., ''Aerodynamics'', Section 14.7 If the pilot were to use only the

ailerons An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

to initiate a turn in the air, the airplane would tend to "slip" toward the lower wing. If the pilot were to fail to use the

to increase the

angle of attack In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a reference line on a body (often the chord line of an airfoil) and the vector representing the relative motion between the body and the fluid through which it is m ...

throughout the turn, the airplane would also tend to "slip" toward the lower wing. However, if the pilot makes appropriate use of the rudder, ailerons and elevator to enter and leave the turn such that sideslip and lateral acceleration are zero the airplane will be in coordinated flight.

References

* Clancy, L.J. (1975), ''Aerodynamics'', Pitman Publishing Limited, London
Coordinated flight
Retrieved on 2008-09-19 {{DEFAULTSORT:Coordinated Flight Aerodynamics