aviation Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' include fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air aircraft such as h ...

, coordinated flight of an

aircraft An aircraft ( 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 the Lift (force), dynamic lift of an airfoil, or, i ...

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 () is the Ministry (government department), department within the Government of Canada responsible for developing regulations, Policy, policies and Public services, services of road, rail, marine and air Transport in Canada, tra ...

: ''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

Instrumentation

Airplane An airplane (American English), or aeroplane (Commonwealth English), informally plane, is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, Propeller (aircraft), propeller, or rocket engine. Airplanes come in a vari ...

s and

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

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 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 ...

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 (American English) or lift (Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems suc ...

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, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...

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 aroun ...

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 flight, flying through the air or in outer space. It is concerned with how forces acting on the vehicle determine its velocity and at ...

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 Airfoil#Airfoil terminology, reference line on a body (often the chord (aircraft), chord line of an airfoil) and the vector (geometry), vector representing the relat ...

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