How to fly an ILS approach:
First of all, what is an ILS??
ILS stands for “Instrument Landing System” The ILS consist of 2 different beams.
- The Localiser (LOC), for horizontal guidance
- The Glide Slope (G/S), for vertical guidance.
The ILS approach is used to guide the pilots onto a specific runway with the help of
the localiser guidance and glide slope guidance.
The Localiser is providing the pilot with data showing if the airplane is on the runway
centreline or not. When you are cleared for the ILS approach this means you need to maintain your present heading until your turn to establish yourself on the localiser.
The Glide Slope will you give a vertical guidance, it will show if you are on the correct
height compared to your distance from the runway. Most ILS approaches are based
on a 3 degrees glideslope. A 3 degrees glide slope means for every 1NM you are
away from the runway you will need 300 feet of altitude. IE:
1 NM you should be at 300 feet above the runway elevation.
2 NM you should be at 600 feet above the runway elevation.
5 NM you should be at 1500 feet above the runway elevation.
There are some exceptions as always, one of the
main exception is London City (EGLC) where the glide slope is 5.5 degrees
How do I know in Infinite Flight if I can fly an ILS approach:
There are a few ways in IF to find out if you are able to fly an ILS approach.
The airport will have a red triangle pointing towards the runway, this means its equipped with an ILS system.
(If the triangle is in white it means there is a GPS approach)
In this example it shows that all four runways from London Heathrow are equipped with an ILS system.
In the right hand bottom of your screen it will show “ILS XX”. So in this example it shows **ILS 27L EGLL**.
What information is available on my HUD to fly an ILS?
On the HUD you will find different data available to fly an ILS approach, There are 3 main ones which I will talk about in more detail.
As described in the beginning the LOC will give you a horizontal guidance in relation to the landing runway.
Here you can see the compass with a present heading of 318 degrees but turning left to intercept the localiser for runway 27Left in London Heathrow. The green line inside of the compass is the LOC, when on final you want this one straight on the small green line in the middle of the compass. At the moment you can see the LOC on the right side so this means it is on the right. Always fly to the side where the LOC is while on final and when you want to correct for wind.
Here an example how it will look when you are on the LOC.
You can see the runway heading is 270 degrees and we are 5.0 NM from the runway. Because the wind in this example is 270/02 we can use the runway heading to stay on the LOC.
The G/S will provide your vertical guidance all the way down to the runway. It works straight forward.
The G/S indications are on the right side of your screen next to your altitude indicator. You will see 2 dots, one line and 2 more dots. Also there is a green triangle but at the moment it is up in the screen as we are way below the G/S. It works straight forward. If the triangle is above the line you are below the G/S, if the triangle is below the line you are above the G/S and you will need to increase your rate of descent to capture it back.
Here you can see that the green triangle is just below the green line, this means we are more or less correct.
Remember: The closer you get to the runway the more accurate the indications will be for both LOC + G/S. Therefore don’t start chasing them on short final.
DME stands for Distance Measuring Equipment and it works in NM (Nautical Miles). The only thing the DME does is it shows your distance to the runway. In the pictures where I talk about the LOC it shows 10.1 & 5.0. You can use this distance to crosscheck your height and use the DME distance to plan for your deceleration.
Speed on the ILS
In real life you will see a lot of times that these are the speeds used by ATC on a busy
180 knots until 10 NM
160 knots until 5NM.
As its well known that an auto land feature will be in the next update please read the following regarding the auto land function.
Do NOT arm the APPR mode until you are on the intercept course and cleared by the ATC controller for the ILS approach. This means, you have to be within a 30 degrees angle of the localiser.
This tutorial is made for ILS approaches but for a GPS approach al indications are the same and it works exactly the same.