X-Plane 11.00 public beta 12 is out. A few notes on the engines:

  1. Jet engine thrust at low N1 should be fixed; you should no longer have to kill the ground crew to taxi around the ramp. If you find weird jet engine N1 behavior, please report a bug ASAP!
  2. Reciprocating props will need to have their idles adjusted, perhaps a bit higher, particularly if your idle adjustment is < 1.0 in Plane-Maker.  We had to bump up our Cessna, which was set to about 0.8 and was stalling if not given a little extra throttle.
  3. The engine start code has some kind of bug that is stopping engines from starting.


If you’re hitting this last case, please file a bug and include the aircraft that won’t start.

From what I can tell, the beta 11 code is actually correct for some airliners, but is wrong for others. I’ll have more details later and I suspect we’ll have a beta 13 that addresses this by Tuesday.

About Ben Supnik

Ben is a software engineer who works on X-Plane; he spends most of his days drinking coffee and swearing at the computer -- sometimes at the same time.

53 comments on “Beta 12 And Engine Chaos

    1. Only if it’s badly set up. From my experience, I can run a 172P at low idle (throttle pulled out as far as it goes) with the carb heat fully pulled (to make it even worse) at about 450RPM or so for a while, and it won’t quit. This is terrible for the spark plugs, and I assume after some time the plugs would get so terribly sooty that the engine does in fact quit then. If the engine quits as part of the runup “throttle idle & carb heat on” test, that is a sign that the idle setting is too low, the idle mixture too richt, or a magneto timing is off.

    2. For fun you may try putting the Cessna at LANGTANG airport (VNLT). I had to add significant throttle to keep the engine running. Also the thin air should require a leaner mixture, but I couldn’t verify.

  1. Hi Ben,
    I experience the last issue (The engine start code has some kind of bug that is stopping engines from starting) with the Airbus A350 Advanced from Flight Factor. Appreciating you looking into this.


  2. I’ve run into the “engine won’t start” issue with my BD-5J. Bummer! I filed a bug as requested.

      1. Same here, Baron B58. There seams to be a big hole in both fuel tanks. When I set the tanks to “full”, they’ll get empty within one second. Plus the Manifold Pressure needle is missing, both in the default and Carenado’s Baron.

        The Carenado Cessna CT182T has no problems with fuel and starts up correctly, but the MP display is also not working (shows „nan“).

    1. I needed to adjust a setting in plane maker engine specs to prevent ITT overshoots and engine fires.

  3. Thanks a lot for the update to communicate us this! Here the only aircraft that works is the iXEG 737, and now the a320 neo cause the beta 4 update! I have a strange bug with the Cessna 172 default that the key ignition is not working… but sometimes work!

    Wait next Tuesday.

      1. “Flight Factor’s 757 and 767 (Lat updated Feb 24th) engines works perfec… test it”
        Sorry, but the Flight Factor 767-300ER Pro v.1.1.27 (latest version) is not willing to start the engines using beta 12 on my rig.

        I just filed a bug.


  4. Hello Ben, I also experienced the engines won’t start, I build all my own aircraft. Which run the gamut from jets to World War I. Same issue

  5. quick follow-up on the engines issue, after doing some testing I found that if I disable the plug-in for the Saitek panels (version 2.57) then I can start the engines. I don’t know if anyone else that is complaining about this issue is using these panels or that plug-in. It appears to also affect the battery switches and I suspect many if not all of the other electrical switches.

  6. cannot add fuel to Carenado CT210 REP. fuel tanks empty back to zero after adding fuel, it worked fine in PB11. if you switch fuel tanks you will see the fuel gages zero out and the fuel flow and manifold pressure needles will disappear.

  7. first let me apologize for the barrage of posts, and forgive me the double post, I don’t know how that happened. Anyway some more testing done and some interesting observations with regards to electrical systems, with the avionics switch on (generator and battery switches off) and no external power, and no engines running, the avidyne panel, the autopilot switches and indicators, and some radio selector switches remain powered on, which shouldn’t be. the lighted brakes indicator also illuminates with no power and no electrical switches on at all. it. when I re-enabled the plug-in even stranger things happen, could the problems be related to the saitek panels plug-in?, apparently when the plug-in is enabled the battery and generator switches appear to actuate the avionics switch as well, regardless of that switches physical position. In any case I suspect something very strange is going on here with the electrical systems. Could this also be tied to engine idle fall off? Because apparently the generator cuts out before it should when the idle is beginning to fall off. I don’t know what the minimum RPM is before generator cut out . Another interesting phenomenon happens if the starter is engaged without batteries on but engine and generator running, all the electrical systems go dead as if the power was shut off but the starter does not engage either. Is this intentional? with engine still running, generator switch to on hit the battery switch and the starter can be engaged with the engine running and the electrical system doesn’t go dead. Curiouser and curiouser.

    1. Given that this plugin does some really strange things as for example overwriting the type of the GPS default waypoint (WTF??), I strongly suggest that you try everything with this plugin removed first. If the issues then still persist, go file a bug in X-Plane.

      1. I’ve had a look at this with Bill (Xsaitekpanel’s author) and here’s what we’ve found out so far:
        1) Xsaitekpanels at no point touches nav_type (not even close), so the effect must be some sort of interlock with other datarefs and/or maybe some of CRJ-200’s internal code.
        2) No other aircraft tested seem to exhibit this. Tried the AirfoilLabs C172, Carenado B1900D, CT210, F33 and V35.
        3) It seems the interaction happens while the CRJ-200 is being loaded and Xsaitekpanels controls the avionics switch (avionics_power_on). If the physical switch is on, then Xsaitekpanels keeps avionics_power_on=1. It appears, the CRJ-200 is trying to lower the value to ‘0’ (maybe to sync it to its VC?), but Xsaitekpanels is preventing that. That’s when stuff goes haywire and nav_type gets inexplicably reset to ‘0’.

        Does any of this sound familiar? We’re honestly scratching our heads here, because it’s really not making much sense to us. Seeing as you have more direct access to X-Plane’s and CRJ-200’s underlying code, your input would be appreciated in helping us work this out. Right now all we can do is ship a workaround config with Xsaitekpanels that just disables the hardware switch on the CRJ-200 and that’s just a bummer for users.

        1. The problem is you are trying to set a switch that is not there physically. In the cockpit of the CRJ-200 there simply is no “avionics master power” switch. The state of the corresponding X-Plane variable is decided by the plane’s plugin. You should not second-guess that and try to set a dataref for a switch that simply doesn’t exist in the cockpit.

          1. Thanks, that clarifies the problem. I believe the solution would be to simply monitor “avionics_EQ” to control the physical switch. I’m gearing up for a rewrite of the whole switch panel logic soon, so that’ll be part of it.

          2. This won’t help in this case, because avionics_EQ will read “1” in the CRJ, so devices can be powered down. But the plane plugin gets to decide whether stuff is powered up or down, not a non-existing hardware switch. Please stop stepping on other plugins’ logic.

          3. Is a log message created in this case (operating non-existing switch)? It sounds like a good idea to me.

        2. “Please stop stepping on other plugins’ logic.”

          I agree, if and only if the aircraft plugin does its best to use the default datarefs and commands!

          Xsaitekpanels, XHSI and other hardware and software cockpit component builders have the same problem: custom aircraft plugin logic that is separate from default logic, without any attempt of fallback.
          I have seen a case for example where the navigation display map range selector in the virtual cockpit changes the default dataref, but not the other way round. All external hardware or software navigation display map range switches will be inoperative.
          Another example is the flight plan of the custom FMC not being copied to the default FMS flight plan, even not a simplified copy.

          If the CRJ200 has its own logic for the avionics power, then it is OK to ignore the position of the dataref for the switch, as long as the dataref for the actual presence of avionics power is correctly updated.

          Cockpit builders are clearly a target for X-Plane, so the aircraft authors would do well to do that too…

  8. The following models cannot start the engine.
    -STMA Pilatus PC-12/47
    -Carenado C-90B
    -LES SAAB 340A
    Also a new bug found. LES Saab 340A asks activation every time loaded.
    SSG 747-8i also does.

  9. I think the C172 isn’t serious looked at the trim behaviour, filed this as a bug but never looked serious at. again guys look at aerodynamics! no elevator controll inputs should hapen when moving just the trimwheel! always erratic trim characteristics right now…… we should not fly an aircraft by trimwheel that is bad habbits. Is it that difficult to program an antiservo tab with its charactristics for an aircraft in X-Plane!? Sim anthusianst don’t care about such they are happy to fly what ever they fly as it looks just good and yhink it is normal, but we realworld student and pilots know that X-Plane can not be trimmed in a way we experience in the real aeroplane…

    At the point in the checklist you should check for freedome of movement flight controles, look back to the elevator hold full aft yoke look to the trimmtab and move your trimwheel back and forth, see the elevator moves with it.. is not ok….just the trimtab should move…

    1. But then we need a force feedback yoke. The behaviour you describe is needed to compensate the spring loaded devices most of us use and always center to the middle regardless the trim settings.

      1. If the sticks wouldn’t center, would we need trim then? I guess yes, because trim also extends the range of control.

  10. Carenado Grand Caravan can not start

    i also have a crash – about pressure – here is the message i see on xplane11 beta 12

    baro pressure out of range
    I am seeing 3431402
    Ooops! Resetting to default now!

    i see also an understood buttom on the low right
    when i click it nothing happen and i have to close xp11 terminating from the task manager

    will try to submit a report if i can – as when this happen there nothing else to do either than come out of it with task manager.

      1. try to file a bug but can not do so – get stuck – and can not go any further. – if get a chance to do so will do.

        also discovered i have 2 set of saitek pedals – right and left toe breaks axes on one of the two pedals are not recognised – in beta 11 where working fine.

        1. AFAIR left and right brake were removed in beta 10 or 11 (and didn’t come back up to beta 13 it seems).

          1. Specific _commands_ to actuate the left and right brakes are gone in v11. Instead we auto-toe-brake with rudder/tiller IF you don’t have hardware brakes.

            DATAREF access to the brakes will come back before we go final, but with the caveat that plugins that want to control the toe brakes will need to set an override in v11 (as opposed to v10). This is needed to hand over toe brake authority from x-plane to the plugin.

            If you were able to assign a toe brake axis using x-plane’s built in mechanism in v11 until now, please file a bug.
            If you are using a third party add-on for toe brakes, that add-on will need to be updated, and cannot be updated until we address the brake datarefs.

            I’m hoping to have the brake datarefs sorted out in the next beta.

  11. Ben, may I suggest a compatibility for older aircrafts?
    Like you did for the torque algorithm update in 10.50 (or so), if the plane was authored with an older version of PlaneMaker, you may keep using the old idling algorithm. If the aiplane is authored with PlaneMaker 11, then you use the new polished algorithm.
    This was a great thing for us in v10!
    It would save plane authors from shipping a new version of their aircraft for XP11 just to fix the engine parameters! 🙂

    1. PS: Also, there is no dataref to control the low/high idle of the engine. This requires the authors to always ship two different acf files if they want to support xp10 AND xp11.
      Maybe, having a dataref to edit the idles may be a good compromise.

    2. We went to the extraordinary step of leaving the old, incorrect code available in X-Plane for binary compatibility specifically because it was a mid-version update. There are some things going on v11 pb12 (e.g. fuel not being introduced) that are just bugs, but there are some parts (changed engine curves to reflect mach number) where we believe the results of the sim are more accurate.

  12. I cannot start a lot of aircraft! Aerobask Epic E-1000, won`t start…the Laminar Cirrus Vision won`t start either…as well as EMB110, Carenado B1900….don`t know what is wrong

  13. Ben,
    I have submitted a bug report on the intermittent problem of the 430, 530, and some glass avionics not powering up. This non-power up is random in regards to aircraft, and occurs with no rhyme or reason. If they do power up they work just fine.

    My Question is, besides log.txt what other files or screen shots could I submit that would help Laminar determine where the trouble may be?
    Does log.txt need to be submitted on each aircraft when the trouble occurs? i.e. its pretty much all default with 430/530 & FMC. Couple of 3rd party but will concern myself with default for now.

  14. Flying beta 13 now and I think XP11 is a triumph so far. Very playable on my mid 2011 high end iMac.

  15. Maybe not quite on point with beta 12. I just installed beta 13 and I definitely now start with engines running in idle. That’s good.
    However, there are still weird things happening with the Airbuses. Flightfactor’s A350 has no thrust (i.e. no reaction to throttle) and engines stay idle. No reaction to flaps, MFD in the middle console is black. If you choose a scenario to set the plane in flight (like “get me lost”) the avionics goes wild and turns itself on and off at random.
    Peter Hager’s A321 also no reaction to throttle and the engines remain idle.

  16. 777 by ramzzess engines does not work, ixeg 737 engine does not work… please release beta 13 fixing this issues. Thanks

  17. My Purchased Boeing 787-8 has throttle has become unresponsive in x-Plane 11. Please fix, it’s my favorite plane to fly! 🙂

  18. Same problem with my Boeing 787 . Throttle not working after beta 13. When I push throttle forward . Computer freezes up ,drops to 2 fps.

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