• I have extensive experience in reporting detailed bugs on mobile flight simulators and have helped developers correct these issues like X-Plane Mobile for example. But the preparation of these reports is quite laborious and I even spend about 1 hour and 30 minutes producing them outside the time I spend investigating the bug in the simulator and reproducing it accurately. I can commit to writing a highly detailed report but I need you to help me too because the more people report the same problem gets even better for it to be identified and corrected. For this specific bug it is necessary to record a video for developers to understand and identify the problem. The video needs to be recorded at the exact moment the bug occurs. At least here for me it has happened several times from the Boeing 787 LNAV and VNAV functions if they turn off on their own without my interference. When they turn off I turn them back to continue the flight.

    I won’t be back in a 787 until probably next week, I did Newark to Madrid today on the 773 and will fly back to Madrid at the end of this week. My next flight will probably be Newark to lisbon so if this does happen again I’ll definitely try to record it. Saying that, LNAV hasn’t disconnected for me recently, I think it might just be the steep turns in the flight plan (although ThomK didn’t seem to have a problem). It’s hard to anticipate when the lnav will disconnect and what conditions have to be met but if it happens while I’m monitoring the climb out of Newark, or even when I get down route to lisbon I will definitely record the replay and show my complete lack of interaction which still causes a pretty crucial flight mode to just disconnect. Maybe my sim is cursed 👀

  • I also encountered this problem on board the C172 when I activated the HDG on autopilot

    hm. maybe the autoflight systems need touching up cos this happens in tht 787, concorde, and the 172 as well?

    or just a fix to ensure the LNAV system doesn't keep routinely disengaging as my case with the 78-10 and concorde, it takes a turn and then ends up in a circle for some reason.

  • it tends to just disconnect and i think try to fly whateevr heading is set in the heading bug, although actually if it did this exactly surely it would straighten out once hitting the heading. It doesn't (the concorde doesnt at least, dont quite remember what the 787 did)

  • It probably is that the turn anticipation of the route is broken again. The autopilot just flies what the route gives it and if that leg switching happens too late then the autopilot can't make the plane turn hard enough with the bank angle limit that it has.

    Oh i see. is there a need for this to be fixed then or is this what should happen anyway?

    • Official Post

    I need to speak to the developer who programs the route why the route no longer checks for the appropriate turn radius and we may also make the LNAV a bit more robust. There are conditions that make LNAV disconnect, based on the criteria found in the FCOM of various aircraft. But obviously they are not working when the turn is overshot.

  • agora, posso ser muito estúpido, mas acabei de verificar meu voo CDG EWR (787) e ele está em uma curva há quase 3 horas. O que aconteceu foi que eu decolei perfeitamente bem, virei e defini o LNAV e a altitude de cruzeiro. Por algum motivo, o LNAV continua desconectando enquanto eu o habilito por cerca de 20 segundos e então ele decide desligar, e é por isso que está em uma curva nas últimas 2 horas e um pouco. Minha pergunta é, por quê? Estou perdendo alguma coisa ao envolver o LNAV ou estou apenas sendo burro? Eu nunca soube que o LNAV simplesmente desconectava magicamente em qualquer tipo de ar condicionado. Isso é um bug enorme ou isso deveria acontecer? Estou realmente irritado porque realmente pensei que estava conseguindo um voo sem problemas. 2 1/2 horas depois, ainda sobre Paris. smh.

    this has already happened to me several times, this since the launch of the simulator, what I can say is to avoid very sharp curves