A pitot tube is a tool used to measure flow speed. Pitot tubes are commonly found on aircraft but have applications on boats, race cars, wind tunnels, and various industrial tools.

Pitot tubes can be mounted on planes in many ways. The most common areas are on the edge of the wings and on the fuselage.

The first pitot tube was invented by French engineer Henri Pitot back in the early 18th century, who used it to measure the flow of the River Seine. The design of the tool was later modified to its current form in the 19th century by French scientist Henry Darcy.


How Does a Pitot Tube Work?

A pitot tube contains two holes that each measure pressure from the incoming airflow. The front-facing hole measures stagnation pressure, and the side-facing hole measures static pressure. The difference between these two measurements results in what is called dynamic pressure, which can then be used to calculate airspeed. A pitot tube with both of these holes are also known as a pitot-static tube.

Some vehicles use simple pitot tubes that only have the one front-facing opening for stagnation pressure, but it is rare for aircraft to do so.

Pitot Tube Maintenance

Pitot tubes are integral to the function of an aircraft and must remain clean and clear, especially during usage. A blocked pitot tube will result in incorrect airspeed readings and endanger all personnel on the flight. The pilot’s ability to pull a correct airspeed is essential to a successful flight as simple errors in maintenance can lead to devastating consequences. For example, a plane that is flying too slowly cannot properly generate lift and risks stalling. Additionally, a plane can easily gather damage by flying faster than the limits of its construction.

When not in use, pitot tubes should be covered and attached with a “Remove Before Flight” tag. A tube left without covers is at risk of being contaminated by dirt, ice, small animals, or insects.

Failure to properly maintain pitot tubes will always lead to negative consequences like flight delays, emergency landings, or at worst, catastrophic aircraft failures. Ground crews and aircraft mechanics should always keep the status of an aircraft’s pitot tubes in mind during pre-flight preparations.

Aviation maintenance technicians are critical to the success and safety of flights. If you would like to pursue aviation maintenance as a career, fill out the form below to get connected with National Aviation Academy!

This image shows the "Remove Before Flight" tag on an aircraft's pitot tube.

A “Remove Before Flight” tag on a covered pitot tube.