– If airplanes flies normally with the standard altimeter setting above 10k feet, why ATC gives to the pilots an exact value when they are below 10k ?

Question

Why bother change it when it works perfectly during the flight ?

In: 3

Answer 1

Because when airplanes are flying below 10,000ft (the start of cruising altitude), they’re generally flying to takeoff or land. Meaning there’s probably plenty of other planes in the area either converging in one area or departing from an area and with so many planes in a certain about if 3-dimensional space, and that they can’t necessarily see each other in that space, air traffic controllers are responsible for controlling and helping them navigate that space to ensure that they don’t collide in air or on the ground.

Above 10,000ft, planes are headed to cruising altitude and are far enough away from the hub where there’s a high density of planes in the space that they can generally navigate and watch out for each other using their own instruments and plane-to-plane communications. There are protocols for how pilots communicate with each other and engage with each other to avoid collision