The ILS and the Course select

[JWMuller 5]

Hello Avsim members!

I am very confused on something called the course select, I always see in the PMDG 737 and some other addons, but I don't know what it is at all. Is it something to do with the ILS?? Could anyone tell me fully what it is, and how do I use it, and what its for? Please include pictures if you can. But sometimes I don't see the course select in some aircraft like the PMDG 777, where is it? Is this because its too modern to need one? Isn't the course select the heading or something? It sounds like it.

Final Question: When landing with the ILS, do I put the heading of the runway into the Course Select?

PS. Could you also tell me where do I put the ILS Frequency in the PMDG 737?   

Any help will  be appreciated

Thanks, 

JWMuller

[JESUS_LOSPI 0]

One of many explanations you can find yourself on the web http://www.navfltsm.addr.com/ils.htm

[pedrotrindade 335]

19 minutes ago, JWMuller said:

 

PS. Could you also tell me where do I put the ILS Frequency in the PMDG 737?   

 

On both NAV radios. I recommend you to read the tutorial 1, it will help you a lot. 

[Chock 17,769]

Basically, you put the radio frequency of a ground based navigation aid into the Navigation radio (Nav 1), then choose a course heading, and select the appropriate mode on the autopilot, usually NAV (typically the selector on the autopilot will be labelled with switches or buttons which say things like NAV, or VOR, but you will also see labels such as APP, LOC, BACK COURSE etc, more on this below). When you fly into range of th nav aid which ou have tuned into on your Navigation radio (usually the range for a VOR beacon is about 30-50 miles, depending on terrain etc), the autopilot with steer you onto that course heading which you put into the course selector, going directly toward the navigation aid. In this way, you can navigate to where you want to go, by flying from one navigation beacon to the next and then the next and so on.

For an instrument landing, you would put the exact magnetic heading of the runway into the Course selector (keep in mind that runway numbers are either rounded up or rounded down to the nearest five degrees when they are named, so Runway 24 might not necessarily be on a magnetic heading of exactly 240 Degrees, it could be on for example, 237 Degrees, so you would have to put that exact heading into the course selector).

Then you would select LOC (localiser) on the autopilot and fly to within about 10-15 miles of the runway on a heading of no more than about 30 degrees off the actual runway heading (this is known as intercepting the localiser). When your aeroplane, gets within about a 50 degree cone of the runway's localiser radio signal, the autopilot will line you up with the runway and turn to the exact course heading to be coming straight at the runway, lined up exactly with it. When you got within about ten miles of the end of the runway, you would select APP (approach) on the autopilot, and the autopilot would then 'fly down' a second radio beam which is fired out from the end of the runway at an angle of about 3 degrees so when the autopilot keeps you in that beam, it will take you on a gradual descent down to the runway so you can land. Not all runways have an Instrument Landing System, and even some with an ILS only have a localiser signal and not an approach signal, in which case the autopilot can line you up with the runway, but you have to fly the descent yourself.

Normally, when doing an automated landing, you put the correct course into both Navigation radios (Nav 1 and Nav 2) and you would use more than one autopilot (these are usually labeled CMD 1 and CMD 2, and you'd press both of them when you selected APP). This is so that if something goes wrong with one of your autopilot systems, it will still work okay.

There are lots of tutorials out there which will show you how to do all that properly (look on youtube for something like ILS tutorial and you will certainly find one). It is worth doing that for a few reasons if you want to learn it all properly, for example; you always fly into an approach radio beam from below (typically at about 3,000 feet above ground when you fly into the beam). This is because the radio signal from the Instrument Landing System transmitter can bounce off terrain and occasionally it will send false echo radio signals above where the true radio beacon's beam is, so you never come at it from above. Also, if you come at it from above, the aeroplane would have to go into negative G in order to capture the approach beam, which would be uncomfortable for the passengers on an airliner.

Older airliners usually have the Navigation radios on the centre pedestal, in between the pilot's seats. You put the frequency into the bit which is labelled STB (standby), and then click the transfer button to make that frequency the active one which you are tuned to. Note that there will be four radios, two of them are COM frequency radios (the ones you talk to ATC on) two are the NAV frequencies, which are the ones you use for autopilot navigation. More modern airliners usually tune the Nav radios automatically when you select a runway on the Flight Management Computer's display unit (i.e. the thing which looks like a big pocket calculator, of which there are a couple in the 737, one for each pilot, but they are slaved together, so it doesn't matter which one you use).

[JWMuller 5]

On 14/03/2017 at 9:25 PM, Chock said:

Basically, you put the radio frequency of a ground based navigation aid into the Navigation radio (Nav 1), then choose a course heading, and select the appropriate mode on the autopilot, usually NAV (typically the selector on the autopilot will be labelled with switches or buttons which say things like NAV, or VOR, but you will also see labels such as APP, LOC, BACK COURSE etc, more on this below). When you fly into range of th nav aid which ou have tuned into on your Navigation radio (usually the range for a VOR beacon is about 30-50 miles, depending on terrain etc), the autopilot with steer you onto that course heading which you put into the course selector, going directly toward the navigation aid. In this way, you can navigate to where you want to go, by flying from one navigation beacon to the next and then the next and so on.

 

So basically The course select is another heading?

Thanks

[Chock 17,769]

Essentially yes, but unlike the Heading select, where you will just turn to whatever heading you put in, instead when your radio is tuned to a nav aid (either a ground based navigation aid, such as a VOR or ILS transmitter), the autopilot will fly you into the compass heading radial which points at that beacon, and then turn you so that you point at that nav aid when flying the course heading you selected.

Think of a ground based nav aid such as a VOR, as being like the hub at the centre of a bicyle wheel, with the spokes coming out from it being all the different compass headings (radials) you could be on when flying toward the hub - you tune your nav radio to the hub's signal, pick a course, and then your autopilot will fly you toward a particular 'spoke' (radial), and then turn toward the hub to fly down that radial toward the centre.

You can imagine an ILS signal in the same way, but only having one spoke (radial) coming out from it, and that one radial is the magnetic course heading which the autopilot would turn you onto to line you up with the runway when you flew into the radio beam.

[JWMuller 5]

19 hours ago, Chock said:

Essentially yes, but unlike the Heading select, where you will just turn to whatever heading you put in, instead when your radio is tuned to a nav aid (either a ground based navigation aid, such as a VOR or ILS transmitter), the autopilot will fly you into the compass heading radial which points at that beacon, and then turn you so that you point at that nav aid when flying the course heading you selected.

Think of a ground based nav aid such as a VOR, as being like the hub at the centre of a bicyle wheel, with the spokes coming out from it being all the different compass headings (radials) you could be on when flying toward the hub - you tune your nav radio to the hub's signal, pick a course, and then your autopilot will fly you toward a particular 'spoke' (radial), and then turn toward the hub to fly down that radial toward the centre.

You can imagine an ILS signal in the same way, but only having one spoke (radial) coming out from it, and that one radial is the magnetic course heading which the autopilot would turn you onto to line you up with the runway when you flew into the radio beam.

Aha, So if I want to head to a VOR, I put in its heading into the CS. Then I put in its frequency?

And with the ILS, I put the runways heading into the CS. Example: RWY 09= 90 degrees heading, so I put this into the CS. Then In put in the frequency in the frequency box below the Radio with the buttons saying NAV1 NAV2 and stuff (in the 737)?

Thanks,

JWMuller

[Chock 17,769]

Yup, in a Boeing 737, to perform an ILS approach, put the ILS frequency into into both nav radios (you can find the correct frequency by going to the FS 'World' menu, choosing 'Map' then clicking on the airport, and you will see all the frequencies for the Tower, Departure, ILS etc listed, plus the runway's exact heading). Put the runway's exact heading into both course windows on the MCP (the one on the co-pilot's side, and the one on your side).

Fly your 737, at about 4,000 to 3,000 feet, toward the ILS feathers, at no more than 30 degrees off the correct runway heading, whilst you are about ten miles away from the airport (the ILS feathers are the green spikes pointing out from the airport's location). You will see your distance from the airport shown at the bottom of your PFD.

Make sure you have your autopilot with one CMD button selected and VOR/LOC selected as well. When your plane steers itself to line up with the runway, look on the right hand side of the Primary Flight Display (PFD), you will see a pink diamond marker moving down the right hand side of the PFD (that's the glideslope signal marker), when it gets right in the middle of the right hand side, press the APP button on the autopilot and press the second CMD button. You 737 will capture the glideslope. Arm your autospoilers by pressing Shift+/. This will make them deploy automatically when you touchdown to slow you down when you've landed, and will also help to stop you bouncing back into the air too. You can also arm the autobrakes if you like, but you only need to do that if the runway isn't very long.

You can either use the autothrottle to control your speed, or control it manually (approach speed for a 737, depending on its weight, will normally be something like 130 knots). Right when you pass over the runway threshhold at around 60-100 feet or so, disengage the autopilot, by pressing Control+Z (and disengage autothrottle if you are using it too). Then ease it down manually with some back pressure on the stick/yoke when you get to about 25 feet above the runway, don't pull back too much or you will risk a tail strike.

A Boeing 737 will actually keep on flying (when at light weight and with plenty of flaps) at speeds as low as 100 knots when at low altitude, since it goes into ground effect where the air under the wings creates a cushion that the aeroplane rides on. So make sure you get off the throttle to slow you down - the 737 is notorious for floating a long way down the runway because of that ground effect.

[JWMuller 5]

On 3/14/2017 at 9:25 PM, Chock said:

 

For an instrument landing, you would put the exact magnetic heading of the runway into the Course selector (keep in mind that runway numbers are either rounded up or rounded down to the nearest five degrees when they are named, so Runway 24 might not necessarily be on a magnetic heading of exactly 240 Degrees, it could be on for example, 237 Degrees, so you would have to put that exact heading into the course selector).

 

I thought I would ask now but I didn't know about the runways being sometimes rounded up to the nearest number. I it always or sometimes?  So how would I know the exact heading of the runway? By charts?

Thanks

[Chock 17,769]

6 hours ago, JWMuller said:

I thought I would ask now but I didn't know about the runways being sometimes rounded up to the nearest number. I it always or sometimes?  So how would I know the exact heading of the runway? By charts?

Thanks

This is a good question, and the answer might surprise some people if they think that is always the case. Whilst it is true that generally speaking, the name of a runway is related to its magnetic compass heading, and usually rounded up or down to the nearest five degree increment, that isn't always true, there are exceptions...

An example of this would be Dallas Fort Worth in the United States (KDFW). That airport has five runways which are all on a magnetic heading of 175.4/355.4 degrees, so you would think they'd all be rounded down to 17 and 35 (depending on which end of the runway you are at), but they can't do that because what would you call them all to avoid confusion when clearing an aircraft to land?!! So, at Fort Worth when you approach it from the West, they are called: 17L (this is the one furthest to the North side of the airport, i.e. on the extreme left as you approach it), 17C (which is the one to the right of 17L), 17R (the one on the right of 17C), then the other two runways on the Southern side of the airport are called 18L, and 18R even though all five runways are oriented at a heading of 175.4 degrees. Because of that, it is a good idea to have a chart of the airport so you know which runway ATC are telling you to land on. Of course if you are coming at them from the other direction (i.e. approaching them from the East), the three of them on the North side of the airport are called runway 35L, 35C and 35R, and the other two on the South side of the airport are called 36L and 36R, even though they are all on the same heading. Confusing or what?!! Especially since there are also two other runways at that airport as well, so it has seven runways in total. Personally, I think the designers of that airport were smoking something when they figured that layout was a good idea lol, but there you go.

So, whenever you fly to an airport, you either need a chart for that airport, or you can get the information from your flight simulator's map. A chart is also useful to show you the names of the taxiways, because even though airports have little signs at the side of the taxiways which tell you the name of that taxiway, it can still be a bit confusing if ATC tell you something like: 'taxi to the holding point for Runway 26 left via alpha, bravo, golf, lima, oscar.' Most of the time, if you type the ICAO airport code into google, it will find the wikipedia page for the airport and there will be a chart you can look at, but if not, in FS you can put your plane at the airport you are interested in, then go to the FS world menu and choose Map and zoom in on the map till you can see the runways, if you click on the runway, it will bring up a dialogue box and if you choose the runway you are interested in, you will see the info for that runway, with what the magnetic heading is and what the ILS frequency is (assuming it is equipped with an ILS facility).

Note that something may possibly catch you out here, and it is because Microsoft Flight Simulator X is eleven years old: The Earth's magnetic pole does not remain stationary, it actually moves about as a result of iron in the magma at the Earth's core moving about. That takes a long time - approximately 200 million years to shift 30 degrees - but it does nevertheless still move about. This means that a few years ago, it shifted to the point where many runways in the world were all on slightly different headings from what they were originally on when they were first built; so any runway which was at for example 34.4 degrees when it was originally built in 1940, might then have shifted to face 34.6 degrees 70 years later!

A good example of that would be my local airport (EGCC) Manchester International; when it was built - in 1938 - it had one runway which was on a heading of about 237 degrees, so that runway used to be called 24/06, but as the magnetic pole shifted, its runway ended up being aligned with about 235 degrees, so in the early 2000s, they renamed it Runway 23/05, and by then the airport had a second runway built too, so the original Runway 24 is now Runway 23R/05L and the second newer runway is 23L/05R.

This has consequences for Flight Simulator. If you install an original old boxed DVD version of Microsoft Flight Simulator 9, or Flight Simulator X, you will see that Manchester Airport (EGCC) has its runway called 24, so it won't match up with a current chart for the real airport. It was patched to reflect that change in the Steam Version of FSX and in the service packs for the original boxed version, but you can still find examples of runways and navigational aid beacons in FS which are not completely up to date, and you can even find airports in FS which no longer exist in real life and not find ones which were built in recent times, so you can still land at Woodford Aerodrome (EGCD) in FS, even though it shut down in 2011 and is now a housing estate called Woodford Garden Village, which is a shame because I used to love going to airshows there and had in the past flown from there, which you can no longer do in real life.

So, if you want to use current real-world charts for FS, one thing you might want to do, is update the magnetic heading data for the FS database and update the frequencies and locations of all the navigation aids in the world, so that your flight simulator is up to date, and you can do that here: http://www.aero.sors.fr/navaids3.html

 

 

[KevinAu 441]

They're rounded to the nearest 10 degree increment, not 5.

[Chock 17,769]

Yup, correct, it is to the nearest cardinal increment of 10 degrees, what I mean is that to do that, it is obiously no more than a five degree shift either way, based on the actual magnetic heading.

[JWMuller 5]

On 24/03/2017 at 11:50 AM, Chock said:

Note that something may possibly catch you out here, and it is because Microsoft Flight Simulator X is eleven years old: The Earth's magnetic pole does not remain stationary, it actually moves about as a result of iron in the magma at the Earth's core moving about. That takes a long time - approximately 200 million years to shift 30 degrees - but it does nevertheless still move about. This means that a few years ago, it shifted to the point where many runways in the world were all on slightly different headings from what they were originally on when they were first built; so any runway which was at for example 34.4 degrees when it was originally built in 1940, might then have shifted to face 34.6 degrees 70 years later!

A good example of that would be my local airport (EGCC) Manchester International; when it was built - in 1938 - it had one runway which was on a heading of about 237 degrees, so that runway used to be called 24/06, but as the magnetic pole shifted, its runway ended up being aligned with about 235 degrees, so in the early 2000s, they renamed it Runway 23/05, and by then the airport had a second runway built too, so the original Runway 24 is now Runway 23R/05L and the second newer runway is 23L/05R.

This has consequences for Flight Simulator. If you install an original old boxed DVD version of Microsoft Flight Simulator 9, or Flight Simulator X, you will see that Manchester Airport (EGCC) has its runway called 24, so it won't match up with a current chart for the real airport. It was patched to reflect that change in the Steam Version of FSX and in the service packs for the original boxed version, but you can still find examples of runways and navigational aid beacons in FS which are not completely up to date, and you can even find airports in FS which no longer exist in real life and not find ones which were built in recent times, so you can still land at Woodford Aerodrome (EGCD) in FS, even though it shut down in 2011 and is now a housing estate called Woodford Garden Village, which is a shame because I used to love going to airshows there and had in the past flown from there, which you can no longer do in real life.

So, if you want to use current real-world charts for FS, one thing you might want to do, is update the magnetic heading data for the FS database and update the frequencies and locations of all the navigation aids in the world, so that your flight simulator is up to date, and you can do that here: http://www.aero.sors.fr/navaids3.html

 

 

Yep, I fly in old airports in FSX and P3D that dont even have an ICAO code any more and have a different name on Wikipedia. Will X-Plane show the magnetic actual heading of the runways,  I think I knwo about FSX and P3D but not so sure about XP...

[JWMuller 5]

On 24/03/2017 at 1:48 PM, KevinAu said:

They're rounded to the nearest 10 degree increment, not 5.

Ah thanks

JWMuller

[jcpg 1]

Hi  Chock,

Just one question, I thought you catch the ILS frequency at about 2000/2100 ft. I've been doing this for some time. It has worked for me. I read your reason for catching it at 3000ft, as the signal might bounce up. I thought 3000ft a bit too high. At that height coun't the plane go into a neg G because of the extra +-1000ft?  Just trying to do it the right way.   Please correct me?

Thanks for the info.

John Goncalves