Air
Speed / Ground Speed
Taking a 60 mile long road trip by car, the driver is fairly sure that if the average speed is 60 miles per hour (mph) for the trip, then it will probably take approximately one hour for the trip (60/60 = 1). This would not be as certain with an airplane because of wind. An airplane's speed can be greatly enhanced or diminished by the wind. This is the reason for the consideration of 2 speeds: ground speed and airspeed. Ground speed is the speed at which an airplane is moving with respect to the ground. Airspeed is the speed of an airplane in relation to the air. (Think of airspeed as the speed at which its propulsion system is set to move it along.) If an airplane is flying with the wind then its ground speed will be enhanced. That means its ground speed will be faster than its airspeed. If an airplane is flying against the wind then its ground speed will be reduced. That means its ground speed will be slower than its airspeed. If an airplane is flying through still air (air with no measurable wind), then its ground speed and airspeed will be the same.
Taking a 60 mile long road trip by car, the driver is fairly sure that if the average speed is 60 miles per hour (mph) for the trip, then it will probably take approximately one hour for the trip (60/60 = 1). This would not be as certain with an airplane because of wind. An airplane's speed can be greatly enhanced or diminished by the wind. This is the reason for the consideration of 2 speeds: ground speed and airspeed. Ground speed is the speed at which an airplane is moving with respect to the ground. Airspeed is the speed of an airplane in relation to the air. (Think of airspeed as the speed at which its propulsion system is set to move it along.) If an airplane is flying with the wind then its ground speed will be enhanced. That means its ground speed will be faster than its airspeed. If an airplane is flying against the wind then its ground speed will be reduced. That means its ground speed will be slower than its airspeed. If an airplane is flying through still air (air with no measurable wind), then its ground speed and airspeed will be the same.
Wind triangle
The wind triangle graphically represents the
relationships among velocity vectors used for air navigation.
The wind triangle is a graphical representation of
the relationship between aircraft motion and wind. It is used extensively in dead reckoning navigation.
The wind triangle is a vector diagram, with three vectors.
- The air
vector represents the motion of the aircraft through the airmass. It
is described by true airspeed and true
heading.
- The wind
vector represents the motion of the airmass over the ground. It is
described by wind speed and the
inverse of wind direction. Note that by convention wind direction is given
as the direction the wind is from. In a vector diagram such as the
wind triangle, wind direction must be stated as the direction the wind is
blowing to, or 180 degrees different from the convention.
- The ground
vector represents the motion of the aircraft over the ground. It is
described by ground
track and ground speed. The ground
vector is the resultant of algebraically adding the air vector and the
wind vector.
The wind triangle describes the relationships among the
quantities used in air
navigation. When two of the
three vectors, or four of the six components, are known, the remaining
quantities can be derived. The three principal types of problems to solve are:
done by: firas mohammed alhammadi
11-04 mohsen mohammed youssef
ammar obaid salem
fund from Wikipedia.com
here is a link to go to a website that we can make some examples:-
http://hyperphysics.phy-astr.gsu.edu/hbase/airpw.html
