Explained: The concern over 5G and flight safety

News: Air India and several other airlines have cancelled flights to the US. They are worried that the 5G roll-out there may affect aircraft and passenger safety, a concern raised by Boeing and Airbus in the past.

Read more about the issue here; https://forumias.com/blog/why-5g-roll-outs-are-disrupting-flights-to-the-us/

How do flight radar altimeters help in safe flight operations?

For all airborne vehicles an aircraft, spacecraft, or even a missile an altimeter is crucial to gauge the altitude and the distance covered.

Altimeters are of three main kinds: barometric, laser, and radio or radar altimeters.

Most commercial passenger and cargo aircraft use a combination of all these altimeters along with global positioning system (GPS).

They are used to determine their path, as well as factors such as height above sea level, presence of high-rises, mountains, and other obstacles, and the likely flying time.

The radio or radar altimeter is a very small, low-power radar system that operates in the 4.2-4.4 GHz frequency microwave C-band.

The high frequency of these altimeters enables aircraft makers to install small antennae that produce powerful signals that can be relayed quickly and accurately.

Why is there concern about radar altimeter interference specifically in the US?

The situation is critical in the US, which auctioned 5G bandwidth in 2021 in the 3.7-3.98 GHz on the C-band spectrum range.

This band is very close to the 4.2-4.4 GHz range in which radio or radar altimeters operate.

According to industry experts, there are chances of interference of the two bands as telecom service operators, in order to extract the full value of 5G and give customers the best experience, push operations to the highest band possible.

Altimeters too need to operate at higher frequencies in order to get the most accurate readings possible.

Source: This post is based on the article “Explained: The concern over 5G and flight safety” published in Indian Express on 21^st Jan 2022.