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All About Altimeters and Their Applications

When operating an aircraft, it is important that the pilot has constant awareness over flight conditions, including things such as remaining fuel, how fast the aircraft is moving, which direction it is moving, etc. With these various readings and data points, a pilot can ensure that an effective and safe flight is carried out or that a safe landing can be executed, if ever required. Many readings provided to the pilot are generated through instruments located in the cockpit, and each instrument has its own distinct role. In this blog, we will discuss the altimeter in particular, that of which is a flight instrument that allows a pilot to know how high the aircraft is above sea level.

One of the most common types of altimeter is the barometric altimeter, and like others, they are able to determine the height of an aircraft above a specific pressure level. These types of altimeters feature internal aneroid capsules that expand or contract based on fluctuations in static pressure, higher values make them compress while lower values cause them to expand. As the aneroid capsules adjust in accordance to pressure, a connected series of gears and needles will adjust on a dial, allowing the pilot to have readings of altitude. To better understand this process, and how pressure is used to make measurements, it can be useful to have a basic understanding of the types of pressures aircraft face during flight.

When discussing static pressure, one is referring to the pressure that something experiences independently from the speed at which it is moving. In the case of an aircraft, this pressure is generally located in areas that are relatively undisturbed by the flow, such as under the fuselage. Another important pressure type for altitude readings is dynamic pressure, and it is the pressure faced by an object as it moves. As such, dynamic pressure increases alongside speed. The final type of pressure that is relevant to the topic at hand is total pressure, and it is simply the sum of static and dynamic pressure.

With this understanding of altimeters and pressures, you hopefully can have a better idea of how such instruments function. As static pressure adjusts based on the height that one is traveling at, the aneroid capsule will adjust in response, causing an accurate reading to be displayed on a gauge or electronic display within the cockpit.

While barometric altimeters are the most common option that pilots use, they are not the only option. Another type of altimeter that may be found in aircraft is the radio altimeter, and they are much simpler with operations similar to a navigation radar. For their operations, radio altimeter instruments send radio waves down from the aircraft toward the earth below. As these radio waves hit the ground and deflect, they are captured and measured by the aircraft again. Based on the time it takes for a beam to hit the ground and reflect back to the aircraft, a height measurement can be determined.

Aside from these two examples, there are other altimeters that may be used, and each comes with its own advantages, disadvantages, regulations, etc. If you are in the market for top-quality aircraft instruments that you can steadily rely on, there is no better alternative to Automatize Buying. On our website, we provide customers access to over 2 billion new, used, obsolete, and hard-to-find parts that have been sourced from top manufacturers that we trust. If you find any items of interest on our database, make sure to fill out and submit an RFQ form at your earliest convenience. Within 15 minutes of receiving and reviewing your submission, a member of our staff will reach out with a competitive quote for your comparisons. Get started today and see how Automatize Buying can serve you! 


December 2, 2022

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