Stock A320 dolphining over 25000 ft in climp

Anyone been able to remedy the A320 dolphining when climbing through fl25?

Have you tried the mod? they say it solves most of the problems A320 by Fly by Wire.

The guy was talking about the stock A320. Whilst I have a lot of respect for the FBW guys and their work, it’s not for everyone, so it not very helpful to just say install the mod.

As for the porpoising, this is because the managed cruise speed in knots is too high for the weight of the plane, and the plane is struggling to maintain speed whilst climbing. Try setting a lower speed, or switch to Mach and keep to .7mach. this will allow it to stabilise, and climb.

Do these housekeeping first:

  1. Set flight model to modern, not legacy.
  2. All assists should be set to Hard/True to Life
  3. AI Copilot control should be off at all times.
  4. Add deadzone to your control axis, at least 5% should do it.

For me, it’s a struggle just to climb up to FL250 and higher. Is anyone else also experiencing this too? I’ve noticed it since the USA update. The default A320 feels very underpowered now and it takes a long time to climb to cruise after takeoff, sometimes between 30-40 minutes.

And I agree with you that the mod isn’t for everyone. I’ve been using the default A320 just fine except for the AP bug which seemed to get fixed and now this climbing issue. Simply telling others to “just install the mod” doesn’t help answer our questions or solve our problems.

True… but that’s the only solution that’s proven to be working for everyone else. Without the mod, the only thing we can do is report the problem and wait while not flying until it’s fixed at an unknown date.

Ok, my initial reply was posted via my phone, which didn’t really allow me to explain due to limitations and time.

Firstly I am assuming you have checked that flaps are up, spoilers disarmed, sim rate is set to 1x and AP in on, altitude and speed are set to managed and the thrust levers are set to CLB.

There has been a change in the model of most planes during the USA update to make the models somewhat more realistic. Prior to that, the A320 has been actually a little unrealistic in Climb rates compared to the real aircraft, in that the aircraft was able to climb to FL180 without any consideration, which is actually very unrealistic. Indeed, reading other posts on this these forums and other places seem to hint that the A320 is now closer to how the real aircraft behaves.

I am not going to go into flight models and the effect of altitude here, and I really suggest you read up on them, and maybe I may put a guide up later explaining.

But this leads you to have to think of a LOT more things to handle now. Just setting a flight plan in the map screen and switching on AP/Auto Throttle/CLB when climbing is no longer enough and a little planning is needed.

First things first, before flying please look at your fuel and weight levels. The more weight the harder it is to climb at any altitude. Try to avoid carrying more fuel than needed. A fully loaded A320 will require more effort to reach higher altitude. I hear that even real A320 pilots often fly at a lower cruising altitude when fully laden, and gradually increase as fuel is burned off.

Secondly, check your Cost Index on the MCDU. The lower the value, the more efficient the computer will try to fly the plane, and that will also limit the climb rate.

Check if you require de-icing. If you are flying through extremely cold/moist air you are more likely to suffer icing. Whilst there is a debate about the level of icing that the A320 is exhibiting on FS2020, there is no denying that ice build up does effect lift, again requiring more effort to climb or even maintain an altitude. Switch on de-icing when needed, though bear it mind it does bleed off some engine power to do so.

As the density of the air decreases, the differences between IAS (Indicated Air Speed) which is displayed on the speed indicator and TAS (True Airspeed) also increases. At ground level, an IAS of 200 knots will correspond closely to a TAS of close to 200knots. As you increase Altitude to FL300, an IAS of 200 is equivalent to a TAS of about 400 knots. The TAS is also effected by temperature, barometric pressure, wind etc.

It is important to know is because whilst the dials, speed settings etc display and react on IAS, you plane behaves, and has limits based on TAS.

When you have your speed indicator set to IAS/knots the plane’s auto throttle tries to maintain a consistent IAS which is wrong, as you really want to maintain a consistent TAS instead, however as above, the TAS/IAS difference increases with altitude. So a 320 IAS at FL330 is a TAS of 660 which is far too fast for the plane. Either the engines will unable to reach such a speed (hence the up down dolphin action) as the computer tries to adjust things to get there. Or worse, you overspeed.

What I do is I switch the IAS to MACH once I pass about FL180 as this will maintain a mach of about 0.7 to 0.8. By doing so, this will adjust more closely to the TAS. I have found that in most flights this will easily allow the plane to reach FL330 and also maintain steady flight. I am aware that previously there have been bugs in this, hence why many suggest use the A320nx mod, however the mach/knots switch has been fixed on the USA/winter update. Also remember to switch the barometric ALT to STD. Just remember to switch back both when going bellow FL180.

If after doing the above you are still struggling to climb, or maintain a steady alt, set the speed manually and reducing it a little. IF your plane is heavy, try requesting a lower altitude from the controller.

Whats worse, I don’t even know if the mod actually solves yours and the “op’s” problem on its own, and i strongly suspect it also requires the same considerations as above. However, as in general the users of the mod seem to be more “exerienced” with the A320, they are makign the changes above as needed.

EDIT: note I am not saying that even with the changes the A320 model is 100% accurate and no flaws exist, but what I wrote above works for me. I dont use any mods, or liveries.

EDIT2: modified to FL180 for transition as suggested by @Yeti64 below.


Lot of good advice in your post. I would sum it up by pointing out the difference between trying to fly the A320 as a “game” versus as a “sim”. There is a crossover point where you run into the simulated realities of the plane’s systems operation and the flight model.

I would suggest that those who want to play the 320 like a game aircraft, reduce the weight, set the CI to get maximum performance, and maybe choose lower flight levels. Then you can “fly” the plane without running into the simulated restrictions of the real plane.

In keeping with the realism theme, the use of the terms “flight level (FL)”, “transition altitude”, and “transition level” needs to be clarified as to their meaning and usage.

In the US, the “Transition Altitude” is 18,000 feet referenced to local pressure. The term “Flight Level” refers to altitudes at or above 18,000 feet referenced to the standard barometric pressure of 29.92 Hg, or 10.13 Hpa. It is incorrect to refer to a FL below 180.

Note that this implies that if you are using anything other than standard pressure, any flight level will not refer to the corresponding altitude. For example FL180 will not equal 18,000 feet unless the local pressure is standard – 29.92.

“Transition level” – “level” = flight level – refers to the point at which you change your barometric pressure back to local pressure when descending from the flight levels. In the US, that is typically FL180. Again, note that this is NOT the same as 18,000 feet unless the local pressure is a standard 29.92.

When ascending from below 18,000 feet, you set your barometric pressure to STD as you cross 18,000 feet local pressure. Note that if the atmospheric pressure is above 29.92, then changing to STD may drop the altimeter back down slightly below 18,000 feet indicated. This is normal.

Note that this is why in some cases ATC will tell you FL180 is unavailable when asking for that FL in a clearance. FL180 is referenced to STD pressure, whereas at local pressure, ALTITUDE 18,000 is slightly above FL180. If they assigned an aircraft FL180, and cleared you to FL190, then the mandatory 1000 foot separation would be broken as you ascended to 18,000 feet before changing over to STD pressure.

When coming down from the flight levels, you reset your altimeter to local pressure as you pass FL180 or maybe slightly above if instructed by ATC. As when ascending, depending upon the local pressure, this may cause your altimeter to read higher or lower than 18,000 feet. Again, that is normal, and is the reason you FL180 as the transition level.


  1. If below 18,000 feet, always have your altimeter set to local pressure.

  2. If ascending, set you altimeter to standard pressure (29.92 Hg) when passing 18,000 feet.

  3. In the US, FL180 is the lowest “flight level”. Referring to anything lower as a flight level is incorrect.

  4. Asking clearance for FL180 is usually not a good idea, because as you fly your route, ATC cannot assign that flight level if the local pressure is higher than standard. It would force them to violate the FAA 1000 foot separation rule.

  5. When descending, change your altimeter from standard to local pressure at FL180 or as instructed by ATC.

This is an example of the “gamer” versus “simmer” scenario. If you just want to play the sim as a game, then these technicalities are of no interest to you. I you want the “as real as it gets” experience, or want to fly on PilotEdge or Vatsim, these are things you need to know and understand.

In my mind the difference is that simmers need to learn to fly the plane and its systems. Gamers need to decrease weight, turn on assists, and otherwise make the airliner fly without having to deal with all the restrictions of simulated reality.


two of the most exceptional posts Yeti and SenseleNoir I have ever read on this forum and I agree with you re #use the mod# argument and a brilliant explanation by SenseLeNoir of the TAS/IAs differences re the FL180 issue I have been having.

‘In my mind the difference is that simmers need to learn to fly the plane and its systems’


I think even on no assists, you can stil fly the game easily without being too “simulation”. This is the setup that I have:

  1. Set flight model setting to modern, not legacy.
  2. Set all assists to Hard/True to Life. (except for the taxi ribbon).
  3. AI Copilot control is set to off, all the time.
  4. Deadzones for all my control axises are at 5% or more.

Now, I am using A32NX mod, which opens a lot of different features available. But the concept is hopefully the same in the default A320. The mod allows you to do full checklist. But I disregard that and made my own simplified checklist that always works at the fraction of the effort even on “simulation mode”.

  1. Create a full flight plan using the built-in world map by selecting departing Gate, and ends in an arriving gate at the destination. This creates a gate-to-gate flight plan and assign the SIDs, STARS, and approaches directly as well. This will save some time and effort putting the approach into the flight computer later on. Easier this way.
  2. Set to use IFR High-Altitude Airways, (only for flights that are 1 hour or longer) or IFR Low-Altitude Airways for short hops under 1 hour flight, For High-Altitude airways, it will either pick 39,000 or 38,000 ft by default. Leave it as it is. But for Low-altitude, you might need to adjust to a higher altitude since they tend to be pretty low. I find 25,000 - 30,000 to be a good altitude for a sub-1 hour flight.
  3. Check the aircraft options. Under fuel and payload. Just reset it back to default. If your flight plan can be covered by the default fuel load, that’s it, no need to adjust anything. If you want a longer flight of over 4 hours or more. Then use the top most fuel slider so it can redistribute the weight accordingly.
  4. Star the flight and you should be at the gate in a cold and dark state.

Here’s the quick pre-flight checklist:

  1. Battery 1 & 2 ON
  2. External Power ON
  3. Align IR 1, IR 2, and IR 3 to NAV in the overhead ADIRS section.
  4. Switch on all fuel pumps.
  5. APU master ON, then APU Start
  6. Go to MCDU, into the INIT page.
    a. Set Cost Index to 100
    b. CRZ FL to the cruising altitude that was set in the flight plan
    c. Press the right arrow to go to page B.
    d. Click on the button next to the ZFW/ZFWCG to bring the calculated weight into the scratch pad in the bottom, then click the button again to save the calculated weight and CG into the field.
    e. In block, enter the fuel on board. Which you can see from the Upper ECAM display under FOB label. If you’re flying on default fuel and payload. This should be entered as 10.62
  7. Go to PERF page in the MCDU
    a. Enter 1 or 2 into the flaps
    b. Trans Alt to 18000
    c. Click on the V1 to calculate the speed, then click V1 again to store the value. Do the same for VR and V2
  8. contact ATC, and get IFR clearance. Set your target altitude given by the ATC in the FCU panel in front and press the knob on the top side.
  9. Activate FD, and once the ADIRS are aligned, you should see the ND map comes to life. You can then request pushback.
  10. Set Engine mode to IGN/START, then flick the Engine master switch 2 to on. Wait for the engine to stabilise, then flick the Engine master switch 1 to on. Let it stabilise.
  11. Once you finish pushback, you can get taxi clearance and taxi to the runway and extend the flaps to 1 or 2 depending on what you entered in the PERF page earlier,
  12. While taxiing, set Autobrake to MAX, and arm the ground spoilers.

On the runway:

  1. Once you get clearance for take off, Line up with the runway, and push the throttle to MCT or TOGA.
  2. Once you reach V1/VR/V2 speed pull back on the stick to rotate and lift off the ground.
  3. Once you start climbing, raise the gear and bring the nose up to 15 degrees.
  4. Turn on AP1. Autopilot will take over the climb and navigation.
  5. Once you pass green dot speed, retract the flaps.
  6. When the PFD displays THR LVR flashes, pull back on the throttle into the CL detent and there it will stay for the rest of the flight.
  7. That’s it, the aircraft will climb on its own on managed climb with the calculated climb rate from the computer. You don’t need to switch to anything in the FCU. The displays should now all show - - - dash symbols except for the altitude.
  8. Once you reach the first assigned altitude, the ATC will give you instructions to climb to the next altitude. Just turn the altitude knob to the next target altitude, and push the knob again to confirm that you’ll be on managed climb to that altitude. The aircraft will start climbing on its own again. And keep doing it until you reached cruising altitude.

Overall, these steps once you get used to it, will spend about 10 minutes at the gate to do all the preparation, another 10-15 minutes for taxiing. And from take off to reach cruising altitude of FL390 is usually about 15 minutes.

The problem with the assists is that, The assists are only useful for simple aircraft like Cessna that doesn’t have complex aircraft systems which the assists could cover. On the airbus, the assists will always “fight” against the aircraft systems. I’ve experienced behaviour such as deviating from the flight path, just because the sim is trying to “assist” you in flying, but what it’s actually doing is fighting the autopilot to do its own thing. Assists would be as frustrating to gamers as it is to simmers too. If you want the joy of flying, Airbus isn’t the aircraft for “casual gamers”. At the very basic level, Airbus is for somewhere between “serious gamers” to “casual simmers”. It needs some basic level of understanding on what the aircraft system does. You don’t need to know everything about the airbus system to fly it. But just enough to know the basic instruments needed and how to set them up.

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I’m humbled and honored – although I must point out that I might be wrong in my statements about gamers versus simmers. I happen to know that Sensei has a slightly different perspective and will probably pipe up any second now.

If not, he reminded me that even the hardest-core simmers like to grab an Xbox controller, jump into external view, and just fly for the fun of it once in a while. That would make them “gamers”, too, wouldn’t it?


A simmer would have this setup in their home.

Agreed. Call me old school – the forum rules won’t allow you to call me anything much worse than that – but I’ve always been attracted to the Boeings because they aren’t “fly by wire”. But I can definitely see the attraction of the Airbus because they ARE fly by wire. If the aircraft systems worked as they should – and as they eventually will – then it’s compelling to be able to fly it in “casual” mode. It goes fast, is the top of the aviation food chain (thing clout and rep), is a favorite in Europe, can let you escape the surly bounds of earth and soar with the angels, and more.

And despite all my bias toward being a hard-core simmer, I’ll admit I jump on the Xbox once in a while and fly “choppers” and blow things up, crank up Forza and race cars, and other stuff like that. I really would like for MS/Asobo to give us the best of both worlds – on Xbox and on PCs. Heck, I know I would at least try it on Xbox to see what it was like, but I would probably fly GA planes and look at cool scenery.


Touche! Don’t think I haven’t dreamed about it! That is awesome.

Very interesting post, and thank you so much for adding the the discussion! Thanks to yoru simplified checklist, I may have to try out the mod again.

To be honest, my own workflow using the Stock A320 is not much different, the only key differences is that i dont align the IR1 - 3, i didnt set the trans alt (though maybe it was already set?) and the step 6d as i am not sure if that is availabel in stock.

The only difference is i do need to switch from Knots to Mach above FL180. I notice when i do that the “target air speed” on the speed tape on the Flight Display Unit does change (usually a little lower), suggesting the AP is changing the target cruise speed to a value based on Mach, rather than IAS which seems to give more leeway to allow the plane to climb higher, though i may be wong? Does the mod differently here?

Yeah, each to their own… I started flight sim back in FS2002, and then FS2004, FSX, and now MSFS. I’ve been flying the Boeing all those times, and I do enjoy flying the mechanical style of it. I even got this Premium Deluxe edition because I wanted to fly the 787.

But once I learn about the airbus fly by wire philosophy, and start flying it. I instantly fell in love with it and I end up leaving my boeing flying style behind. I’m in IT industry for a living, so computers are my life and blood. So seeing how advanced computers could integrate with aviation the way the airbus philosophy is, I’m already sold.

It may seem strange to you, but I actually enjoy more when I “program” airbus to fly the way I want it to fly, than actually flying a non-fly by wire aircraft like Boeing. I trust in computer systems more than I do my own flying skills. Hahaha. But this is just me, and to each to their own. Now my 787 is just sitting in my hangar and I haven’t touched it for months.

You don’t need to do this in the mod. The mod switches between Mach and Knots automatically at different stages in the flight. So throughout all my flights, the airspeed is always on managed mode. I never touch the airspeed knob at all. The aircraft manages the airspeed automatically on climb, cruise, descent.

The only time I ever touch the airspeed knob, is when I’m a bit impatient on cruising, so I pull the knob to selected airspeed mode, then turn it to about 0.81 or 0.82 Mach, and bring it just under the overspeed limit, flying within that “coffin zone” just so I can get to my destination faster. But as soon as I was about to start my descent, I push the airspeed knob to make it - - - again and it’ll slow down to the optimal airspeed for descent automatically.

On approach phase, the aircraft also slows down automatically once passed the Decel point. And it also targets lower airspeed the more flaps you extend automatically as well until you’re on the optimal approach speed.

I can understand to a point that people may not want mods. We shouldn’t have to rely on mods to get things to work right. But that’s the state of things right now. File a Zendesk ticket to report the issue. Then you have these options available:

  1. Wait for the next patch in 2 weeks and hope Asobo caught the error and fixes it. In the meantime:
  • fly the default A320 in its broken state adapting to its shortcomings;
  • fly something else other than the A320 until the issue is resolved; or
  • if you’re one of the “I only fly the A320” crowd, fill your time with another activity instead of MSFS until they fix it.
  1. Install the FBW mod and enjoy the plane now.
  • fly a working plane that’s much better than the default A320 now.

Bellyaching in the forum about how you don’t want to use FBW the mod and how you want the default A320 to work is pointless. Until they patch it hopefully with the next major update (no, they won’t release a hotfix), you’re stuck with the A320 in its current state.

We shouldn’t HAVE to use mods to fix broken planes. The plane should work. I couldn’t agree more. But the reality is that this is not the case right now. You can either accept that and help yourself by either dealing with the plane as-is, getting the mod, or go play something else.

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Couldn’t say it better myself… Hahaha.

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