#Airplane localizer how to

Now that we can be correctly aligned with the runway, we want to be able to land the airplane at the correct moment, without overshooting nor aiming too short on the runway. The airplane is correctly aligned when it receives both a 150Hz and 90Hz signal, at the same intensity of course. The same thing happens, only in the opposite direction if the airplane only receives a 150Hz signal. This is a drawing of the two signals emitted from the localizer, seen from above the runway.īy having two different signals, this allows the airplane approaching to know if it is correctly aligned: if the ILS instrument in the cockpit receives only a 90Hz signal, then the pilots know that they are too far to the left, and must head right. This localizer emits two different radio frequencies, one to the left of the runway at 150Hz, and one to the right at 90Hz. Here is a picture of a localizer antenna at the end of a runway. The localizer is an antenna situated at the far side of the runway, after it (the ILS system is designed for one specific approach direction of a given runway), and emit two different radio frequencies. Let’s start with the horizontal one, the localizer. There are two different indications given by the ILS: a horizontal and a vertical indication. This system uses radio waves, emitted on different frequencies that the plane can “hear” and with that know if it is in the correct position. It works by providing two information to the pilots when they are doing their final approach indicating them the correct flight path to take to land correctly on the runway. This system is quite self-explanatory it is a system used to land using instruments (understand without visual information). We are going to talk about a very useful tool, the Instrument Landing System. For a few decades now, most airplanes that are allowed to fly IFR (Instrument Flight Rules) use all sorts of aids in order to land during bad conditions. And after the war, when airmail services started being created, the same issue had to be solved.Īirplanes going faster and faster, flying higher and higher, being more and more technical, it was needed to fit them with something that could allow flying in a wider range of conditions.įirst, they had radios, to get help from people on the ground lights were fitted on the runways to be able to show them to the pilots during night or low visibility flights.

But this was an issue that had to be solved.ĭuring WWI, there was an urge to be able to take-off at any time, whatever the conditions the war doesn’t wait for good weather.

#Airplane localizer how to

The early day pilots didn’t have much of a choice on how to deal with this: in case of bad weather or conditions, they simply wouldn’t take-off and fly.