ILS landing with Airbus

[lee.dickinson37]

Can't work out what's going wrong with this, but the plane seems to have a mind of its own, steering into the ground, flying in circles, just flying off or suddenly climbing to 16,000ft and the like on approach?

Must be something I'm overlooking, but can't work out what it is? Did one ILS landing, but the rest have been disastrous. I've got my AP and Autothrottle on, I'm set to Nav with the correct frequency in Nav 1 and all the beeping noises, with LOC on so it connects with the ILS?

Can't think of anything I'm missing from that list?

Do I need the heading hold on or off? Which heading goes in the HDG bit and which in the CRS? I can see two headings, maybe I've mixed them up?

Thanks for yourt help.

[APUtech]

lee, you don't need the HDG indicator on for an ILS approach, but you do need to have the runway heading entered in the CRS. If the rwy you're landing on has a Glideslope, once the GS "bug" starts trending downward, press the APP (approach) button so that your airplane will automatically descend at the proper final aapproach angle. If you're doing a LOC or GPS approach you have to manually adjust your descent primarily with power settings and secondarily with pitch for a roughly 3 degree angle to the rwy.

When performing an ILS approach, be sure that you intercept the ILS signal at or *below* 3000 ft AGL (above ground level) and use airspeed (primarily) to keep the GS bug centered. I hope this helps. :-)

APUtech

[lee.dickinson37]

Thanks for taking the time to reply. Yes, that helps. Okay, well the runway heading might've been the problem then? Where, exactly, do I find that? I can see two ILS headings when I click on the airport on the map, but not sure if it's one of those or another heading?

Think I have been above 3,000ft a few times, but not the last time and it still went wrong?

So do I basically need to line it up myself then press the APP? All the tutorials I've seen have had the plane turning itself 90-odd degrees and lining itself up?

[APUtech]

You're very welcome, lee!

You can intercept the ILS signal at up to 45 deg or less preferably no less than about 10nm from the airport, but a straight-line intercept works too. I usually get lined up (terrain permitting) as far out as 20nm from the airport, but make sure that I'm at about 3000ft within 10nm of the airport at about 210kts, slowing to final aproach speed (roughly 140--160kts, depending on the jet's recommended approach speed) at 4-6 nm from the runway threshold. I already have my CRS set to the rwy's magnetic heading, my NAV 1 set to the rwy frequency, and if I've been navigating via GPS, switch it off (usually) between 10-15 nm out, so that the Nav 1 radio can track and align itself with the rwy. Double-check that the NAV/LOC button is *on* in your AP.

If you need the rwy's ILS NAV 1 frequency and rwy's magnetic heading that you set your course to, one way is to go to the map, and click on your desired airport. You'll be shown the rwys' headings, surface type, length, and corresponding ILS frequencies and their rwy magnetic headings.

Another way is by using the GPS; that method is a bit lengthy to explain, though. If you're familiar with default Garmin GPS you'll discover how to get rwy frequency information by fiddling with it or by reading about its use in the Learning Center.

Remember to press the APP button *only* when the GlideSlope bug starts trending downward. If I left anything out, please let me know; maybe another pilot will chime in with their sugestions. :-)

APUtech

[MightyCaco]

I don't know much about the default airbus (I normally tinker around with the aerosoft version), but the concepts should be relatively the same.

You tune in the runway's localizer frequency and course, and then need to intercept the localiser beam at a certain angle.

APUtech is pretty close in describing how to approach. You want to cut in at about 45 degrees (usually 30 works nicely), and about 10 miles out. 2500 feet above field elevation generally works splended, but if you want to be right on your descent profile, you should be about 3000 feet at 10 miles. If you have default ATC on, you will normally be "vectored"/directed on intercepting the ILS localizer, provided one exists at the airport and runway you are landing on.

Basically, what is supposed to happen is that you will cut in on the approach path at an angle, and below the glide slope. Your localiser (tells you your horizontal deviation from runway track) should come in first, and then the glide slope bug should come down after that. After that, you fly the needles down towards the runway.

If you are flying on autopilot, you CAN leave the heading hold/select right where it is at provided you are intercepting the ILS at an appropriate angle (one normally does if getting ATC vectored). But you should press the Approach mode button on your autopilot panel (FCU) before you intercept the localiser. Typically in real life, this is pressed when ATC "clears" us for the approach. Once the autopilot picks up the localizer, it will disengage heading hold automatically, and once the glide slope centers, it will initiate a descent.

You do not have to wait for the glide slope to come down before pressing the Approach mode, although some pilots suggest pressing LOC first when intercepting an ILS, followed by the approach mode afterwards once the localizer is intercepted. LOC allows the autopilot to maintain a lateral track to the runway only, while Approach mode does that and picks up the glide slope. Why press LOC first? Because it prevents your aircraft from doing crazy things in case of a false glideslope (erroneous readings that you will never get in FSX, and which one would likely not get if intercepting below the glide slope in the first place).

One thing to keep in mind, especially if you are flying the default Airbus, is that you should disconnect the autopilot around or at least 200 feet and land manually. This is because the default aircraft do not have autoland, and 200 feet is generally the minimum altitude in which a pilot should be able to see the runway in a category I approach (may vary slightly depending on locale).

[lee.dickinson37]

Brilliant responses, fellas, thanks. Going to try these tips later and see if I can get the thing down again. Cheers.

[yellowjacket]

Originally posted by lee.dickinson37:

Can't work out what's going wrong with this, but the plane seems to have a mind of its own, steering into the ground, flying in circles, just flying off or suddenly climbing to 16,000ft and the like on approach?

Must be something I'm overlooking, but can't work out what it is? Did one ILS landing, but the rest have been disastrous. I've got my AP and Autothrottle on, I'm set to Nav with the correct frequency in Nav 1 and all the beeping noises, with LOC on so it connects with the ILS?

Can't think of anything I'm missing from that list?

Do I need the heading hold on or off? Which heading goes in the HDG bit and which in the CRS? I can see two headings, maybe I've mixed them up?

Thanks for yourt help.

You are having problems because the default Airbus 321 is coded by default as a Fly By Wire (FBW) plane. A pilot flies a Boeing and a systems manager Computer flies the Airbus. No where in this post has that been pointed out to you and everyone assumes the FSX Boeings and FSX Airbus are the same type plane.

Lets get technical about the way the Airbus works.

The way the flight controls function is determined by the control law in use. Normal law is the intended method. If things are broken, the system will fall back into a less-capable control law, roll direct law for the ailerons and yaw mechanical for the rudders.

In normal law, the aircraft is in one of 3 modes:
ground
flight
flare

For roll and yaw, flight and flare mode work the same.
In ground mode rudder pedals control the rudder.
In flight / flare modes, sidestick left/right deflection provides a rate of change input to a computer (ELAC) which computes required roll (aileron/spoiler) and yaw (rudder) providing turn coordination and yaw damping. The command is sent to a second computer (FAC) which actually drives the rudder surface.

In roll direct law, the sidestick causes ailerons/spoilers deflection proportional to stick position. No signal is provided for yaw. Instead, yaw mechanical law is invoked and the pilot operates the rudder pedals through mechanical linkage.

If you want the Airbus to fly and land like the Boeing you must change the Control Law. On leftside of the upper overhead panel find the FLT CTL section.

Turn off 3 switches that say
ELAC1 (elevator augmentation control)
SEC1 (Spoiler/Elevator Computer)
FAC1 (drives the rudder surface)

One of your original statements says the following.

Originally posted by lee.dickinson37:

just flying off or suddenly climbing to 16,000ft and the like on approach?

Landing the default FSX A321 can be tricky and there is a learning curve. If you fly too slow on approach the fly-by-wire system will do its best to prevent a stall and will automatically throttle the engines and pitch the nose up. You will have no say in this and it will just happen. You will see "A/Floor" on the PFD and the plane will increase speed and climb regardless of your control inputs.

There is nothing more frustrating than getting close to touchdown only to have the plane automatically throttle up on you and climb away from the runway.

[MightyCaco]

I didn't give the default Airbus too much credit, since I only put in about 10 minutes some years back, and spent more time on a payware alternative. So, I was a little surprised that FBW was modelled somewhat decently when I fired it up this morning.

It is true that the Airbus comes with many protections. Basically, it is an aircraft that protects one from mishandling it. The Fly-By-Wire system also allows you to pitch and roll without the need for trimming..

This all said, the aircraft is still fly just like any other aircraft so long as it is not mishandled, so in all honestly, I wouldn't be too concerned about normal, alternate, and direct laws, unless one is actually trying to get type rated on the thing. It is in fact easier to fly on normal law anyway.

Just be sure not to fly too slow on landing. If you approach an impending stall, the alpha floor will kick in and throttle up (in other aircraft, it may stall, or initiate a stick shaker). Approach and landing is essentially the same as it is in most aircraft. What is basically supposed to happen on landing is that you more or less fly it onto the runway on a stable glide path at approach speed, and you make a small flare and cut the power around 20-30 feet. If you are high and fast, you may opt to cut it sooner.

[lee.dickinson37]

Cheers for your detailed responses. I seem to have nailed it before reading them, and have managed a few perfect ILS landings now, although all your information is great to have on hand. Occasionally the Airbus is still either landing me short or climbing and flying above the runway, but I think this is just a case of not intercepting the glideslope correctly. Great tips, thanks.

[lee.dickinson37]

Just landed the 747 with these instructions too, so thanks again everyone.

[galax17]

Thank you Yellowjacket for your instructions on how to take control over the default Airbus A321. Much appreciated