737 flight model bugs

  • Compared the Aerofly 737-500 with the original Boeing QRH data and noticed some significant differences.


    Like with the Macchi, the base FM seems to be ok, it’s just when you start to extend the flaps that the differences in attitude and thrust required are becoming quite large.


    If the clean performance is valid this 737 seems to weigh approx 11000lbs and e.g. at 10000ft and at 245kias the pitch attitude should be 4.5° which exactly matches the Boeing data.


    The thrust setting required should be 66% while it is actually 60% which fits to my impression that the engines are overpowered.
    E.g. optimum climb at 280kias at 10000ft would need 8.5° pitch and results in a ROC of 3200ft/min at climb thrust while the Aerofly version climbs at 13° pitch and 6000ft/min (90% N1 set as climb power)


    Another significant problem is the apprach, especially with flap 30 where the pitch should be 2deg and 58% N1 at 132kias.
    The Aerofly version needs 155kias! to achieve the same pitch attitude with a still way too low (52%) thrust setting.
    With flaps 40 the pitch IRL is 0.3deg at 65% N1 and 128kias while this version has a 5deg nose up attitude but still needs only 52%N1.


    Another important item is the slats/flaps scheduling. IRL the slats don't retract until the flaps are fully up.
    Presently, when going from full to up, slats and flaps retract simultaneously.


    2 other items;
    The main ADI differs by almost 3deg with the info bar and the standby AI at e.g. 10deg pitch.
    The VSI also needs to be re-calibrated as it shows 2000ft/min while the actual ROC/ROD is 2400ft/min

  • 2 more bugs.


    1. Speedbrake extension causes a strong nose down moment. Should be neutral (or even a tad nose up) like on your 747.
    2. Slat extension/retraction logic wrong. Should be like on your 747. IRL the slats always extend first and retract last.
    If you e.g. go from flaps full to up, the slats and the flaps presently retract simultaneously.