Airport Windsock 101: Everything You Need to Know

During the 40s and 50s, air travel was a more luxurious option than travelling by land or sea. In the late 60s and 70s that slowly started to change as air companies started offering more affordable flights. Today, air travel is available to everyone and because of that various advanced systems are used to control air traffic.

However, there is one system that has stayed in use since it was first used in airports. The windsock can still be seen on airports today and it is used to determine the direction and speed of the oncoming wind. Wind is important when flying high as you need to ascend up in the air with a heavy metal body. Proper reading and positioning of an airfield windsock are key as this piece of textile is one of the most reliable ways to tell wind speed and direction.

How to Read an Aviation Windsock

Colours

Windsocks come in various different colours such as orange, red, white, and yellow but red and white are the most common. They do not have any letters or logos, just red and white stripes. A proper airport windsock must have two different colours for the best reading as every stripe tells you the wind speed. Without wind, it’s impossible to read wind speed.

Wind Speed

Wind speed is determined by how straight the windsock is. An airport windsock usually has three stripes of red and two stripes of white. If, for example, one red stripe is blown up by the wind (not hanging down) it means wind speeds are reaching 5.5 km/h (3 knots). If one red and one white stripe are blown up, it means wind speeds are reaching 11km/ h (6 knots) and so on. Every stripe, be it red or white, adds additional 3 knots (5.5 km/ h). If the windsock is in a horizontal position it means wind speeds have reached 28 km/h (15 knots) or higher.

Other Specs

You must know that the length of the windsock always needs to be 2.5 metres and the throat diameter 45 cm or 3.6 m long. The framework of an airfield windsock needs to be able to hold the throat of the windsock fully open even when there is no wind. The fabric needs to be colourfast and water-repellent too.

How to Mount a Windsock

The Pole

To set up a windsock you must first place the pole that you mount it to. The pole is usually made from heavy-duty aluminium and it can be either a permanent or a temporary solution. Placing the pole is a matter of just stabbing it into the ground but not before you’ve picked the right location.

Location

The location of a windsock is determined by the type of application. The pole needs to be placed in a spot where no building will be in its way. It needs to be visible and not placed by a building adjacent to its position. This will affect the direction of the windsock and get in the way of proper wind speed identification.

Swivel System

A swivel system is made to keep the windsock secure and to let it move freely around the mast in a 360° motion. The two most popular swivel systems are swivel arms and cages. A swivel arm system is the simplest to set up as it only requires you to fit a harness on one end of the windsock and on the arm. A swivel cage is attached with two rings and the windsock is pulled over the cage to be attached at the end. A swivel arm system is ideal if a windsock doesn’t need illumination. No matter the type of swivel system you use, it needs to be able to keep the fabric of the windsock from getting tangled around the pole and from getting damaged.

The Windsock

To mount the windsock onto the pole’s swivel system, a swivel system with an arm will make use of a harness that you’ll need to attach the windsock to. A swivel cage has a band of eyelets with which you’ll need to secure the windsock to the mast using cable ties.

Windsock Maintenance Tips

For a windsock to be working properly you need to take care of it the right way. You must do regular inspections to ensure that the material of the windsock isn’t torn or damaged as this can affect its performance. You need to check whether or not the cable ties or harness of the swivel system have loosened. Also, make sure to check the mast and the swivel system itself. The movement of the system shouldn’t be obstructed and the mast needs to be in good condition, any damage needs to be taken care of properly.