Airbus A-310 autopilot on climb

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Hello,

So I’m currently in the process in learning the A-310 but I’m running into an issue that I could use some help with. Whenever I engage the autopilot after take-off and also engage the level change, the aircraft just seems to level off initially, making it speed up faster than I can retract my flaps and then it slowly and gradually pitches up.

Am I doing something wrong here? I expect that when I engage the autopilot, the plane will hold whatever position the nose is currently pointing. Surely it shouldn’t make the aircraft level off.

2

Have you tried engaging alt hld?

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No but wouldn’t that just hold the current altitude? I thought you needed lvl chg if you want to ascend or descend?

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Does the A310 have a climb speed setting in the MCDU that it accelerates to before starting to pitch up? That’s what it sounds like is happening, but I’m still learning the plane too and don’t know that for certain.

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5

I don’t think so. The MCDU is quite simplistic really. There’s not that much that you can program in it, compared to more modern Airbusses and Boeings.

And as far as I know, LVL CHG should hold whatever speed you dial in into the autopilot panel. So let’s say you set your autopilot speed to 220 knots and you turn on your LVL CHG, than the aircraft should ascend or descend based on the 220 knots.

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Level change is more of ‘altitude intervene/command’ mode. Basically it would hold the set speed and then climb or ascent on that speed. Pumping the rest of the engine thrust in climbing to the target altitude.

It’s often used when Air Traffic Control sends an instruction to the aircraft during the approach, as it ignores all the presets from the flight management system with your vertical profile and restrictions.

The profile mode (next to the level change) is the one best used for climb. Note that the aircraft will hold altitude/speed restrictions regardless of the altitude target. (So it’s perfectly fine to set a target of 15,000 feet and witness the aircraft not going past 8,000 feet when an altitude restriction would be in place). After passing the restriction, it will automatically continue the climb to the target altitude.

Usually you won’t find many restrictions during climb though, they are more to seperate you from the terrain when approaching an airport.

Normal behaviour would be to set the target altitude. Hit profile climb. Watch the aircraft accelerate to 250 knots below 10,000 feet (it’s a standard speed restriction). It will then climb (pretty steep) towards the target altitude at speed 250 knots. After passing 10,000 feet, the aircraft will first accelerate (speed always comes before vertical speed), and then continue it’s climb on the accelerated speed towards the target altitude.

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7

I am having the exact opposite, i can’t seem to land, it just does not seem to bring me in etc and i completely miss the runway, i have watched endless tutorial videos but no matter what i do i can’t land

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Well what exactly happens SabaruDave? Maybe we can help.

Make sure to be good on your weight and fuel planning first. Don’t just fill up the tanks and try to land it, big jets dont work like that so fuel planning is important.

Second. SHE’s a heavy girl meaning they have quite some difficulty with losing height vs. losing speed. Whenever she descents, gravity pulls and so speed goes up. It’s important to descent well in time with a big one like this. Get your flaps and gear in order some 10 miles DME the first few times and just watch it stabilize as you get accustomed to working with so much mass. THere’s no need to hurry things in the sim when you’re learning and trying to get comfortabel with new equipment. Hell, thats how pilots learn in real life too in a simulator, right? :slight_smile:

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Okay, so its a short flight i am doing EGBB to EGPF, everything up until the point where start the decent is fine then thats where it all starts going very wrong and completely to high and miss the airport all together, its an ils approach to 05, the route and weights etc are all entered correctly, i just don’t now whats going on maybe i am missing something, i done this route 100s of times in the a320 with no problem, but this aircraft is completely doing my head in

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Well it’s hard to figure out exactly what it could be, based on this info.

But I’ll just tell you what I did today and yesterday. This morning I had a short haul too from Rotterdam The Hague Airport into Basel Mulhouse. Flight time 01:00 hours. Cruise level FL350.

I use PRO-ATCsr which offers me in flight information on what arrivals to expect. So about some 80 miles before the ‘rough estimate Top Of Descent’ I check that information and feed the approach data well in time before hitting the TOD.

Now because this is a big aircraft, I requested the initial descent from air traffic control some 20 miles before actually hitting the TOD. It then assigned me an initial descent altitude of FL250, I dialed that in, pressed profile and then nothing happened. I remembered from a video how the A310 would only descent AT the TOD, unlike a modern Boeing/Airbus that you would use assign an initial descent and watch it going at -1000 feet per minute untill catching up with the vertical profile.

So I then instead hit Vertical Speed instead. Dialed in -10 at first (-1000 feet) and after I watched the engines spool down and the nose gently seeking for a descent pitch, I increased descent to -15 shortly there after. Again, as we’re working with mass here, it’s perfectly fine not to rush her.

I then got re-cleared to FL160, and at some point the vertical profile was catching up with me. You can follow the exact deviation from the vertical profile on the PROG (Progress) page, in the top right corner it will either read plus or minus the deviated height.

As the path catched up with us, I switch from VS descent to profile descent and watched how she gently started following that mode instead, taking her down and slowing her down.

ATC kept re-clearing us to lower altitudes and at about 15,000 feet I think, we lost the vertical profile as it went underneath us. Here is when heavy’s get trouble with losing speed and altitude at the same time. So I just applied the speedbrakes/spoilers and watched her catch up again.

ATC then started vectoring us into Basel which is pretty familiar on French approaches and as we left the lateral profile, I started working with level change instead. Mostly with spoilers applied to help her descent and the lower speeds.

ProATCsr also assigns maximum speeds so at some point we were assigned 220 knots and as we made our way into the localiser I started slowing down to ‘clean minimums’ at 209 knots (which is the least possible speed the aircraft can fly without deploying flaps (I don’t know how familiar you are with jets so I just explain a lot, helps newbies reading this too anyway). THen as we turned into the localsier I deployed slats, slowed down to 185 knots. Then started with the flaps as we worked our way down. And I too was full flaps established at 10 miles DME. She intercepted the glideslope perfectly as we lowered the gear to give some extra drag and I disconnected the AP at about 1500 feet AGL I think (low level clouds were obscuring the runway before that) and then we touched down nice and dandy.

So. That worked for me. Hope it may work for you and others too.

With big planes: be in front of them. Always know/feel that you’re working with a lot of mass both in the vertical profile but also during turns on the lateral profile. It’s just big so she needs her time. Be in front of that and they’re usually very fun to work with.

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It seems to be hit and miss for me. Sometimes it does the ILS perfectly, sometimes it doesn’t. Sometimes it does intercept the ILS course but not the glideslope. Had that today actually which was a bit annoying since there was thick fog in the airport that I went into. Had to do the entire approach by manually following the ILS course and GS lol.

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Is it realistic to expect a ~5000 FPM climb in profile mode? Seems pretty steep to me, more like what you might get in a light business jet.

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Solid info from @SkyVagrant4490 in this thread. Good stuff! Thank you, really appreciate the time and effort you put into your posts.

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On the A310 it is actually. Well, not when she’s all fueled up to make the whole 5000 miles, but when prepped for a short/medium haul, the aircraft will certainly push around 4000 feet per minute upto a height of about 12,000 feet, give or take. I 've seen it pass 20,000 will still 2,500 of vertical speed and it has a reason too.

Note how the A310 was one of the first aircraft to receive ETOPS certification (Extended-range Twin-engine Operational Performance Standards). Before that, all oceanic transit aircraft would have four or three engines. In fact that’s how the DC10 and MD11 got their silly tale engines as they wanted to cut down from four but weren’t allowed yet to cross oceans with only two engines.

So the A300 and the A310 where amongst the first to go ETOPS and they weren’t quite experienced with it yet. So they just fitted these aircraft with HUMONGOUS engines that were well able to provide sufficient power with only one running. They then needed a big tail rudder to compensate for. And this is why Airbus later on experimented with the A330 doing two big engines, and the A340 (which is the same aiframe design) with four small engines, getting the smaller tale as she would suffer less asymmetric thrust when losing an engine in flight. Well, losing thrust of course, not the entire engine. You should definitely not lose an entire engine during flight. That’s just wrong.

So, back to the A310. Small aircraft, big engine. As they were new to the whole concept they didn’t take any chances and just fitted her with these two beasts. When they work together, they’ll sure produce you that 5000 feet per minute. It’s only later as they grew more accustomed to it and engine technology developed that engine performance was more sane again.

Also. Please not that you should select the engine thrust settings (next to the gear lever) to either flex or auto. (It will go to auto after flex takeoff). Don’t have them run at TOGA all the way up to cruise. If you’re gonna to not bother with flex settings, adjust for climb performance manually on that same panel. It will still provide you with a good 4000 feet a minute below 10K when in climb mode though.

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Very helpful information and history, thank you!

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16

I had similar issue where it wouldn’t climb on autopilot after 10k feet, turns out I had ground spoilers armed, when I disarmed it, the plane started to climb again

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After take-off, when I engage the autopilot I get the problem where the nose dips and I lose about 300ft before the plane then realises and starts climbing again. No idea why it keeps dropping the nose, I have engine thrust set to Auto and autothrust is on.

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Are you setting your trim before take off?
After you input your fuel, passengers and cargo you should see the CG value and trim value you need to set on your trim wheel, I had the same issue until I realised I need to set my trim correctly before take off