Early 2021 San Jose Learjet crash cockpit still.

  • Your screenshot shows a pitch trim of zero degrees. How did you manage to get into this situation so that we can perhaps change the behavior of the flap trim? What settings do you have turned on or off, do you use limited frame rate or not and what kind of frame rate are you experiencing. Is it laggy at all?


    The flap trim compensates the pitch changes due to flap configuration changes. It should not conflict with the auto-trim function assistance. So as long as the auto-trim is turned on in the settings it should always re-trim automatically.


    The flap trim only engages above a certain speed and only when you raise or lower the flaps. It is designed to add or remove enough trim to avoid any flight path changes when you fly at a constant speed and extend or retract flaps. The plane will pitch up or down but the vertical speed should stay relatively constant. So if your plane is trimmed for a certain airspeed and you extend flaps for example it should remain trimmed to roughly the same speed.

  • Good Day Jan,

    The device is an iPad Pro 9.7”. I had not downloaded any of the add-on scenery at that Aerofly Learjet flight time (it ALL went in perfectly, first attempt).


    The auto trim is off,

    I want to be in control of ‘my’ aeroplane in manual flight, auto trim in the sim means I cannot do throttle adjustments and come back to exactly the previous flight balance feel (if trim is needed, I want to do it).

    (Good trimming is a precious real world skill (I posted a PC FS2 737 trim rate alteration, in mobile I change my tablet’s average tilt). The Airbus is not my first choice 🤐)


    I have frame rate limit on and off and do not notice any difference, there is no frame rate counter available in iPadOS but it seems smooth and fluid and constant.


    I have

    control type tilt,

    cockpit interactions on,

    invert views control inverted

    advanced view movements on,

    flight information off,

    approach guides off,

    landmarks off,

    HUD horizon is on, size middle of slider,

    send flight data off,


    Running the flight

    standby fuel pumps on,

    pitch trim primary,

    parking brake used,

    spoilers armed (default),

    seat belts up,

    landing lights up,

    other lights default,

    anti icing off.

    Take off was with flaps one, retracted at about 185 knots.

    Landing was flaps one below 250, two below 200 and full below 150 knots.


    This occurred in the second flight of a fresh install of a new version of Aerofly, I didn’t have time to muck things up!


    As I wrote above, I think flap trim works to add nose down but does not work in reverse for nose up, the movement seems to be one way. The trim started off OK but after about three take offs and landings the accumulated flap trim built up to full nose down.


    The secondary pitch trim operating control only seems to give a single small pulse. A very large number of inputs are needed to make a small change.


    I have just found that with frame rates unlimited it took five full flap landings to develop full nose down pitch but with frame rates limited it took one landing and on the second full flap approach the trim was full nose down.


    I did not use the secondary trim or try to use the control column switch. I did not use the pitch trim bias control below the seat belt switch.


    15 feet up. After one previous landing, frame rates limited, fresh Aero start.

  • I think flap trim works to add nose down but does not work in reverse for nose up, the movement seems to be one way. The trim started off OK but after about three take offs and landings the accumulated flap trim built up to full nose down.

    Ah ok, now it makes sense to my. The flap trim uses a gain that changes with airspeed. At lower speed there is a different gain than at high speed. So if you extend flaps from up to 10 degrees at 250kt and then slow down to 200kt and then retract the flaps you no longer have the same pitch trim as before. This is done to make sure that the pitching effects are as small as possible.

    I can maybe rework the flap trim so that is adds a fixed value to the trim no matter what the speed is. That way it would be a reversible processes and cannot accumulate over time.


    Just to confirm. If you set the pitch trim switch to secondary, the flap trim should stop and the pitch trim in the console beside the switch should allow you to trim. Is this the case?