Airport segmented circle?

Question

Can you please clarify what the segmented cirlce is? And also what the arms sticking out mean?

Thank you!

Answer 1

The segmented circle identifies the traffic pattern at airports, and is usually found on the smaller airports.

Traffic patterns for visual flight rules, or VHF flight is basically a rectangle.

The runway is one side of this rectangle. Then there's the departure end and you can either turn left or right after climbing approximately 500 feet, this is known as crosswind and this is the width or short end of the rectangular traffic pattern.

Then you turn in the same direction again, e.g. if you turned a left crosswind, you turn left again.

This would you put you on the downwind leg, parallel to the runway.

Then you fly down past the runway and turn again perpendicular to the runway, this is called base.

Then you descend and turn to the runway and make your landing, this is called final.

Now, the legs sticking out tell you which way you should make your turns in the traffic pattern. Think of the legs as the corners of the rectangle. If you want to land at the runway, you must turn the same way the legs are.

If the leg is pointed out and to the left, that means you should make right-hand turns in the traffic pattern when coming in to land in the direction the leg is pointing to the segmented circle.

Answer 2

The circle indicates the direction of traffic flow. When you approach the field you can see whether it's left or right traffic, which refers to the direction of your last turn onto final approach.

The pattern is established in order to avoid obstacles like hills, towers, or densely populated areas, which reduces noise and danger to  folks on the ground.

Pattern direction is also shown on sectional air charts, and given by radio by the tower or Unicom operator when you notify them of your intent to land. You get a message like "Left traffic runway three four wind three two zero at six altimeter two niner niner seven report downwind."

At night the circle and wind sock are lighted.

Answer 3

Take a look at  AC 150/5340-5C  it explains it all (complete with picture/diagrams)

http://www.faa.gov/airports_airtraffic/a...