Weight and Balance



  • This aircraft appears to be inherently out of balance and is slightly right wing heavy. The optimal loading to achieve the best weight and balance is as follows:

    Pilot - 170 lbs
    Copilot - 130 lbs
    Luggage - 100 lbs

    Fortunately, I have my default pilot set to male and copilot set to female in MSFS... so this loading is also very realistic.


  • JF Staff

    Thanks for the feedback. Our flight dynamics expert is looking into this to see if any changes are required to improve realism.

    Martyn



  • @Martyn, Thanks for looking into this... I noticed that in the flight-model.cfg file the Pilot and Copilot lateral locations are slightly different, but they are not mis-matched enough to account for a 40 lb. weight imbalance.



  • @Martyn,

    After more investigation, it seems that the weight and balance of the aircraft is not the actual problem... Reducing the copilot weight is only compensating for the real problem, which is the configuration of the engine_wash_on_roll parameter in the flight-model.cfg file. There is a duplicate entry for this parameter which first sets it to 1, followed by another entry that resets it to 0. The results of this setting is a slow right roll that looks like a weight imbalance.

    Editing these settings as shown below results in wings level cruise flight with no slip, using a balanced payload (170 lb. Pilot and 170 lb. Copilot)...

    [FLIGHT_TUNING]
    engine_wash_on_roll =0.7 ;1
    ;engine_wash_on_roll =0


  • JF Staff

    @RetiredMan93231 said in Weight and Balance:

    engine_wash_on_roll

    Thanks, I'll pass that info to our flight dynamics creator!



  • Just to let you guys know that I made the corrections to the flight model and the aircraft handling in the ground improved considerably, being able to keep the plane nose at the centerline during all the take off run...



  • @RaulKO, are you using the suggested 0.7 value? Is it related to pilot - copilot situation @RetiredMan93231 has mentioned, or a generally good value?



  • @RetiredMan93231 said in Weight and Balance:

    @Martyn,

    After more investigation, it seems that the weight and balance of the aircraft is not the actual problem... Reducing the copilot weight is only compensating for the real problem, which is the configuration of the engine_wash_on_roll parameter in the flight-model.cfg file. There is a duplicate entry for this parameter which first sets it to 1, followed by another entry that resets it to 0. The results of this setting is a slow right roll that looks like a weight imbalance.

    Editing these settings as shown below results in wings level cruise flight with no slip, using a balanced payload (170 lb. Pilot and 170 lb. Copilot)...

    [FLIGHT_TUNING]
    engine_wash_on_roll =0.7 ;1
    ;engine_wash_on_roll =0

    How extensively have you tested to make sure this doesn't have impacts in other areas of the envelope? I like what you've found for improving the take-off roll, but what all does this value effect in other phases of flight, is it perhaps negatively impacting the work JF has done on making the aircraft fly correctly? I'm just trying to create conversation because sometimes a good thing in 1 place is a bad thing elsewhere...



  • @sluflyer06 That is a good question. Anyhow there is a clear error in the official config file now, as the attribute exists twice with different values:

    [FLIGHT_TUNING]
    engine_wash_on_roll =1
    engine_wash_on_roll =0
    

    As a software specialist, my assumption is that with this setting the result is that the parameter's actual value will be 0. Which is probably not the intention of JF.