A320 Auto Pilot Tips or Resources?

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Has anyone here come across any good guides on the A320 auto pilot use?

I normally watch all of the “320 Sim Pilot” videos on YT but his video on AP is more confusing than helpful as he spends most of the time frustrated that the plane in August doesn’t work at all like the real thing.

Anyway, are there any other good resources out there you would recommend?

And, if anyone’s up to it, I’d love a simple explanation of the different modes and when you would use them. There’s managed vs select mode. And different speed and climb modes. It’s not at all like the AP in a GA aircraft which is what I’ve been using for the last few months.

Thanks!!!

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I think 320 Sim Pilot is already the only person that can explain how to fly the A320 in simplest form.

Basically:
Managed mode is an autopilot function that “manages” your entire flight phases from take off, climb, cruise, descent, and approach based on the inputs that you entered in the MCDU computer. Values such as Cost Index (CI), Cruising Altitude, Weight and Center of gravity, as well as fuel on board, all are calculated to give you the best optimal airspeed for all of these phases.

Selected mode, is where you want to disregard all that computerised calculations and fly the way you want it to.

So for example, on Managed mode, you would have a calculated optimal airspeed for climbing. When you take off and start climbing and set your target altitude in managed mode. Your aircraft will take the airspeed as a priority. It needs to be able to reach and maintained the optimal airspeed before it can start climbing. That means, if you have a climbing airspeed of 285 kts. The aircraft will not climb/descend until it can fly with a stable 285 kts.

Same goes for approach, the aircraft autopilot already has a set airspeed that it will fly depending on your flaps configuration, as you extend the flaps, when you’re flying on managed mode, the autopilot will automatically target a new lower airspeed that’s optimal for your approach. This will ensure you’ll be descending at the right rate, with the right pitch attitude.

On selected, you have to determine that speed for yourself, if you know the right airspeed, you’ll get it right. If you get it wrong, the aircraft will behave strangely, like excessive positive nose pitch if you’re too slow, or nose down pitch if you’re too fast.

Another thing of note is the Auto-Thrust. In the airbus, it’s very simple. The thrust lever is divided into “modes”. We have IDLE, AUTO, CLB, FLX/MCT, and TOGA.

You take off by pushing the thrust lever to FLX/MCT or TOGA depending on whether you want full thrust or reduced thrust to save engine wear. When you start climbing, pull it back to CLB mode. And you just need to keep it that way for the rest of the flight. Let the Auto-thrust system manages the appropriate thrust in managed mode.

Even on low speed approach, you would still need to have the thrust lever set to CLB. And only pull it back to IDLE when you flare for touchdown on landing.

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Thanks for that great explanation.

As far as I can tell, managed mode is equivalent to Nav mode on a G1000 system, where the plane is basically flying itself along the flight plan route. The difference here is that the AP also controls the throttles/speed. Select mode is more like the non-Nav mode on a G1000. You fly the plane by turning the knobs.

Is that a safe way to put it?

If that’s close to a good way to summarize it, then what I don’t get is why each knob has a managed and select mode. It would seem to make more sense if there was just one switch that you could toggle everything between managed and select. I guess what I’m saying is I don’t see a situation where I want to select the heading but have the altitude and speed managed by the route. Does my confusion by this make any sense?

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Thanks, will watch those tomorrow. Appreciate the links!

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That’s more or less correct. The reason why you have both Managed and Selected for each knob is to have a more control over what you want to be managed by the autopilot, and what you want to make decisions to yourself.

Altitude:
When used in Managed mode, they will take into account the altitude constraints for each waypoint in your flight plan, and will only climb/descent up to the maximum/minimum altitude that was set for each waypoint. The aircraft will automatically climb or descent to the next waypoint constraint.

On Selected Mode, the pilot tells the aircraft which altitude they want to fly in. if the ATC tells them they should climb/descent to a certain altitude that’s not in the flight plan (for whatever reason), the pilot uses the Selected mode to override the altitude set in the flight plan.

Heading:
On Managed mode, yes, it acts like a NAV mode where the flight will follow the set flight plan navigation from waypoint to waypoint.

On Selected mode, the heading will use the pilot’s assigned heading course to override the nav flight plan.

Airspeed:
On Managed mode, the airspeed will target the optimal airspeed based on your fuel load and consumption, safety margin as well as airspeed restrictions. This includes airspeed for each given flaps configuration and approach speed. The autopilot automatically set these airspeed targets for the auto-thrust to follow.

On Selected mode, the pilot will determine the airspeed they want to fly in regardless of how they’re calculated in the MCDU. Sometimes ATC will give instructions to fly under a certain airspeed that’s different from the MCDU, you use this selected mode to override that.

Believe me… you will experience this situation very often. For example, if the ATC needs to to climb with a certain airspeed, you would want to override the airspeed to selected, but keep the altitude and heading to managed. Because if you have a single knob to activate all to either managed/selected. You’ll be able to control your airspeed, but your heading won’t be able to follow the navigation flight path and you have to turn the heading yourself as well.

With separate systems, you can manage/select each functions separately.

The Airbus is a highly computerised advanced aircraft. They don’t fly the same way as a GA does, even it has flight computers that’s different from Boeing. The airbus autopilot not only assist you in flying. It does the flying for you. And most of the times, all you need is to program the flight computers accordingly, and it’ll fly itself.

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Thanks. I get it now. That makes a lot of sense. Very well explained. Much appreciated.

I guess my next thing to learn, and maybe there’s some reading I can do, is what all the modes that display at the top of the PFD mean.

For example, there’s several different climb modes that can display, different thrust or speed modes, different colours, etc.

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I understand the confusion. The A320 is a different beast from Boeing A/C. I’ve never flown an A320 (or any jet), but I am a PPL SEL and an ex ATC for 11 yrs., so this is what happens IRL. Say you’re being vectored for an ILS approach to a city, now you’re on hdg mode and not nav mode any more. Now you’re behind multiple traffic on the same approach, and you’re asked by ATC
to slow from 240 kts to 160 kts. Now you’re out of managed spd mode, and in select speed mode to maintain 160 kts. Now suppose that due to traffic, you’re asked to cross a waypoint ahead at or below a certain altitude, managed altitude won’t cut it, because you need to do it faster, therefore you select vs, which takes you out of managed mode, and you decrease rate of descent fast enough to make the restriction. In the sim world, you don’t often need to deviate from your established flight plan and approach. In the real world, that’s the exception and not the rule. So that’s the explanation, that situations come up that require a solution, and that’s why you have more than just a managed flight plan by a computer.

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This should give you a good resource to learn about the a320 instrument and systems.

http://www.a320dp.com/A320_DP/nav-autoflight/sys-13.3.0.html

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I had a good IFR/ILS flight in the A320 today… I can’t really say I flew it, I took a ride and turned a knob from time to time. LOL. Pilots are almost an optional accessory on this thing. :wink:

Thanks for all the help and resources… it made everything a lot more clear. It’s actually fairly straight forward but there’s a lot of depth and options to it.

A few lingering questions…

  • How soon after take off do you normally engage AP?

  • While on my flight, ATC was giving me instructions to climb and descend as you would expect. In fact, it was unusual that their demands actually made sense for once. I dialed in the new altitude and pushed up to allow the plane to manage it. I assume that’s the right thing to do most of the time? I’m guessing you would only use select mode for altitude changes if you wanted to ignore any restrictions and get the plane moving up or down faster?

  • When do you normally disengage the AP on approach and hand fly it down? What’s the correct procedure? I did so at about 500 ft AGL

  • I notice one of the guys in the video above let it fly all the way to the ground (Auto Land) but videos I’ve seen from 320 Sim Pilot on that topic lead me to believe it’s not reliable. What do you guys say?

  • My flight plan had me at around 280-300kn most of the flight. If I want my flight plan to include a faster airspeed at cruise, how do I set that? Without overriding it using the AP control?

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For me, when I lift off with a positive rate… retract the gears, and pitch the nose to 15 degrees. Once that’s done, engage the AP1, and let it do its thing. Usually around 500-1000 ft…

That’s right.

I disengage mine on 100 ft callout. It’s probably not the correct procedure, but it works for me. I just find it there’s no reason to disengage the auto approach if you’re not seeing any problems. I would disengage earlier if I see my localiser is offset from the centre and I need to do a sidestep manoeuvre to correct it. Or if you think your automatic approach prevents you from landing at the right place at the right rate. Othewise, there’s no reason to disengage the AP until the final 100 ft, in preparation for the flare.

Currently, there’s an ILS bug, where the Glideslope diamond will drop straight down as you cross over the runway threshold. Since the AP is following the glideslope diamond, it will try to “chase” the diamond, resulting a severe nosedive onto the runway. Unless this is fixed, avoid auto-landing procedure for now.

Pull the airspeed knob to selected mode, then turn the knob to your desired speed. Be aware that you shouldn’t set the airspeed more than the Vmax otherwise you would overspeed the aircraft.

Usually if you enter a Cost Index of 100 into the MCDU, it would give you a faster optimal airspeed on managed mode. But you have to do this at the gate at the start. But if you still want to push faster, just switch to selected mode.

When you’re about to reach the top of descent before you start your descent, push the airspeed knob again to switch back to managed mode. This should slow your aircraft down in preparation for your descent.

Feel free to watch my A320 video collection on YouTube. this is one example that I’m proud of. Haha.

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