A CIESE Realtime Data Project

# CIESE -Navigational Vectors - Lesson #3

Lesson #2

## Lesson #3Wind Velocity

Lesson #4

### A) Flying in the Wind

1. Imagine that you are walking in a blizzard with howling winds all around you. How will the wind affect your movement if it is blowing:

b) directly towards you
c) from the side

Flying a plane in the wind can produce the same effect. A pilot generally wants to fly in the shortest path between two cities. Why? Well, it saves time and fuel. The wind, however, may prevent her from doing this. See how the wind affects a plane's flight by looking at the simulations below.

2. How can the wind affect a plane's flight?
3. What does a pilot need to do to compensate for the wind?

### B) Determining Wind Velocity

Winds in the northern hemisphere normally blow from west to east. This can change dramatically, however, when there is a front moving across the continent. Velocity is another example of a vector. Wind velocity is indicated by the wind speed and direction.

Pilots use wind maps that show the wind velocity at the altitude of the plane. A special symbol on the map called a wind barb shows the both the speed and direction of the wind (wind velocity). Learn more about how to read wind speed and direction on these maps using the links below.

1. Practice drawing a wind barb to represent a wind velocity of 35 knots blowing from the southwest at an angle of 250º (as measured from 0º North).
2. Although wind barbs indicate the direction the wind is coming from, when using wind velocity vectors it is more common to indicate the direction that the wind is blowing towards. For the wind barb you drew above what is the direction that the wind is blowing towards?
3. Look at the wind map below. Select a map of upper air conditions at 3000 feet. This weather map has wind barbs that indicate wind speed and direction. Estimate the wind speed (knots, mph, and km/h) and direction wind is blowing towards (degrees measured from 0º North) in your home state.

 Hints To help get a more precise measurement of wind direction in degrees, try overlaying a compass rose on the wind map. You can convert knots to other units using a unit conversion calculators.
4. Now look at the wind velocity in your home state at 30,000 feet. This is a typical cruising altitude for a commercial plane. Do you see any differences? Estimate the wind speed (knots, mph, and km/h) and direction wind is blowing towards (degrees measured from 0º North) in your home state at this altitude.

### C) Resultant Velocity

1. Imagine that you are flying a plane over your home state. Your altitude is 30,000 feet. The controls in the plane are set so that you are headed due North at 400 km/h. Draw a vector to represent your plane's velocity. Make sure to draw it to scale.

2. What was the wind velocity (speed in km/h and direction) over your home state at 30,000 feet? Draw this wind velocity vector so that its tail is at the head of your plane's velocity vector. Make sure to draw it to scale.

3. What is the plane's resultant velocity?

4. Do your results make sense? Why or why not?

### D) Ready to become a Pilot?

1. Suppose that you are accompanying a friend on his first airplane ride. Your friend is nervous because it is a very windy day. Demonstrate to your friend with a model or paper airplane how the flight may be affected by wind patterns.

2. What are the trade-offs for traveling in different seasons?

3. Create a special notation or symbol to describe a river current of 4 m/s flowing south-east and explain how to read it.

4. Imagine a world with no wind. What other things might affect an airplane's flight on this imaginary world? Be creative! Write a short story that describes the flight of a plane on this world. (Optional)

5. Find examples of how wind affects sports activities, architectural designs, or other real world applications. (Optional)

6. Draw a diagram showing all of the forces acting on a plane. (Optional)

7. Research and then demonstrate with a model or paper airplane how vertical wind sheer forces affect flight take-offs and landings. (Optional)