Tailwind
Encyclopedia
A tailwind is a wind
that blows in the direction of travel of an object, while a headwind blows against the direction of travel. A tailwind increases the object's speed and reduces the time required to reach its destination, while a headwind has the opposite effect. Tailwinds and headwinds are commonly measured in relation to the speed of vehicles — commonly air and watercraft — as well as in running
events — particularly sprints
.
In aeronautics, a headwind is favorable in takeoff
s and landing
s because an airfoil
moving into a headwind is capable of generating greater lift
than the same airfoil moving through tranquil air or a tailwind
at equal ground speed
. As a result, aviator
s and air traffic controller
s commonly choose to take off or land in the direction of a runway
that will provide a headwind. In sailing, a headwind may make forward movement difficult, and necessitate tacking
into the wind.
of an aircraft requires the calculation of the head or tailwind.
Assume:
Then
For example: if the wind is at 24015 that means the wind is currently from heading 240 degrees
with a speed of 15 Knots and the aircraft is taking-off from runway 18, giving it a heading of 180 ...
Formula to convert degrees into radians: Radians=(pi x degrees)/180
The aircraft is said to have 13 knots of crosswind and 7.5 knots of headwind.
Aircraft usually have maximum headwind and crosswind components which they cannot exceed. If the wind is at eighty degrees or above it is said to be full-cross. If the wind exceeds 90 degrees it is common practice to takeoff and land from the opposite side of the runway, it has a heading of 360 in the above mentioned example.
Assume:
Then
For example if the wind is at 09015 that means the wind is currently from heading 090 degrees with a speed of 15 Knots and the aircraft is taking-off from runway 24; having heading of 240. We will use the runway side with less than 90 difference from wind direction, in this case Runway 06; heading 060.
Formula to convert degrees into radians: Radians=(pi x degrees)/180
The aircraft is said to have 7,5 knots of crosswind and 13 knots of headwind on runway 06, or 13 knots of tailwind on runway 24.
Aircraft usually have maximum tailwind and crosswind components which they cannot exceed. If the wind is at eighty degrees or above it is said to be full-cross. If the wind exceeds 100 degrees it is common practice to takeoff and land from the opposite end of the runway, it has a heading of 060 in the above mentioned example.
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
that blows in the direction of travel of an object, while a headwind blows against the direction of travel. A tailwind increases the object's speed and reduces the time required to reach its destination, while a headwind has the opposite effect. Tailwinds and headwinds are commonly measured in relation to the speed of vehicles — commonly air and watercraft — as well as in running
Running
Running is a means of terrestrial locomotion allowing humans and other animals to move rapidly on foot. It is simply defined in athletics terms as a gait in which at regular points during the running cycle both feet are off the ground...
events — particularly sprints
Sprint (race)
Sprints are short running events in athletics and track and field. Races over short distances are among the oldest running competitions. The first 13 editions of the Ancient Olympic Games featured only one event—the stadion race, which was a race from one end of the stadium to the other...
.
In aeronautics, a headwind is favorable in takeoff
Takeoff
Takeoff is the phase of flight in which an aerospace vehicle goes from the ground to flying in the air.For horizontal takeoff aircraft this usually involves starting with a transition from moving along the ground on a runway. For balloons, helicopters and some specialized fixed-wing aircraft , no...
s and landing
Landing
thumb|A [[Mute Swan]] alighting. Note the ruffled feathers on top of the wings indicate that the swan is flying at the [[Stall |stall]]ing speed...
s because an airfoil
Airfoil
An airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....
moving into a headwind is capable of generating greater lift
Lift
Lift may mean:* Lift , a mechanical force generated by an object moving through a fluid* Lift , rising air used by soaring birds and glider, hang glider and paraglider pilots for soaring flight...
than the same airfoil moving through tranquil air or a tailwind
Tailwind
A tailwind is a wind that blows in the direction of travel of an object, while a headwind blows against the direction of travel. A tailwind increases the object's speed and reduces the time required to reach its destination, while a headwind has the opposite effect...
at equal ground speed
Ground speed
Ground speed is the speed of an aircraft relative to the ground. Information displayed to passengers through the entertainment system often gives the aircraft groundspeed rather than airspeed....
. As a result, aviator
Aviator
An aviator is a person who flies an aircraft. The first recorded use of the term was in 1887, as a variation of 'aviation', from the Latin avis , coined in 1863 by G. de la Landelle in Aviation Ou Navigation Aérienne...
s and air traffic controller
Air traffic controller
Air traffic controllers are the people who expedite and maintain a safe and orderly flow of air traffic in the global air traffic control system. The position of the air traffic controller is one that requires highly specialized skills...
s commonly choose to take off or land in the direction of a runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...
that will provide a headwind. In sailing, a headwind may make forward movement difficult, and necessitate tacking
Tacking
Tacking may refer to:*Tacking or coming about, a sailing maneuver*Tacking , a technical legal concept relating to competing priorities between security interests arising over the same asset...
into the wind.
Headwind component
Pilots calculate the Headwind Component, Tailwind Component and Crosswind Component of any wind, if they do exist. The direction of wind is calculated using wind sock. Headwind and Tailwind are cosine functions of the wind while Crosswind Component is a sine function. Headwind and Tailwind do not occur together in normal conditions. Determining the ground speedGround speed
Ground speed is the speed of an aircraft relative to the ground. Information displayed to passengers through the entertainment system often gives the aircraft groundspeed rather than airspeed....
of an aircraft requires the calculation of the head or tailwind.
Assume:
Then
For example: if the wind is at 24015 that means the wind is currently from heading 240 degrees
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
with a speed of 15 Knots and the aircraft is taking-off from runway 18, giving it a heading of 180 ...
Formula to convert degrees into radians: Radians=(pi x degrees)/180
The aircraft is said to have 13 knots of crosswind and 7.5 knots of headwind.
Aircraft usually have maximum headwind and crosswind components which they cannot exceed. If the wind is at eighty degrees or above it is said to be full-cross. If the wind exceeds 90 degrees it is common practice to takeoff and land from the opposite side of the runway, it has a heading of 360 in the above mentioned example.
Tailwind component
Pilots calculate the Headwind Component, Tailwind Component and Crosswind Component of any wind, if they do exist. Headwind and Tailwind are cosine functions of the wind while Crosswind Component is a sine function. Headwind and Tailwind do not occur together in normal conditions.Assume:
Then
For example if the wind is at 09015 that means the wind is currently from heading 090 degrees with a speed of 15 Knots and the aircraft is taking-off from runway 24; having heading of 240. We will use the runway side with less than 90 difference from wind direction, in this case Runway 06; heading 060.
Formula to convert degrees into radians: Radians=(pi x degrees)/180
The aircraft is said to have 7,5 knots of crosswind and 13 knots of headwind on runway 06, or 13 knots of tailwind on runway 24.
Aircraft usually have maximum tailwind and crosswind components which they cannot exceed. If the wind is at eighty degrees or above it is said to be full-cross. If the wind exceeds 100 degrees it is common practice to takeoff and land from the opposite end of the runway, it has a heading of 060 in the above mentioned example.