Recent content by jx_

  1. J

    Cruise table

    the same as you would anywhere. coefficient of drag after adding induced drag, parasite drag, and all other drag together. CDqS gives the thrust you need at cruise.
  2. J

    P3D v4 Drag in relation to weight

    I already explained it. Garbage in Garbage out. The sim uses the correct math for everything I have checked. ACES screwed up on inter-dependencies and static coefficients such as not adding the lift from Lift v Mach to the induced drag equation; and ground friction. The fuel Flow is...
  3. J

    P3D v4 Drag in relation to weight

    Never said that...for the weight stations to give accurate MOI the body MOI needs to be set correctly. Otherwise one or the other overpowers. This will also affect performance causing questions such as "why are my control surfaces too sensitive when I use the real coefficients?"
  4. J

    P3D v4 Drag in relation to weight

    no, it's garbage in garbage out. The air file MOI are wrong. FS uses the same equation that is used in real world FD.
  5. J

    P3D v4 Drag in relation to weight

    yes, ideally. I'm no expert on the coding but maybe simconnect can do it by modifying the drag coefficient directly.
  6. J

    P3D v4 Drag in relation to weight

    "the lack of official information (FSX or P3D) on the use of the .air file allows interpretations " These interpretations ARE the problem. I'm almost certain your jet suffers from excessive thrust. There is an exact amount of thrust that must be produced for a given climb rate because level...
  7. J

    P3D v4 Drag in relation to weight

    There is an easier way to do this and do it correctly. If you use a spoiler you will affect all the wrong aero characteristics. Add fuel tanks with no useable fuel. For example, to model a 1000lb payload, position the tank using the X,Y,Z coordinates in the air file and set total and...
  8. J

    Friction coefficient of taxi/runways 0.023?

    you could also use a fuel flow mod and add the additional ground drag to your thrust table under mach 0.2 If the real airplane requires 10000 pounds of thrust and the sim requires an extra 2%, adding 2% to your thrust tables from 0-0.2 mach would have the same effect on performance assuming...
  9. J

    Lowering Aileron Effect / Performance at slower speeds?

    This is an incorrect statement. Cl_r is very much a part of normal flight. 1538 allows you to scale Cl_r based on AoA. A good example of this is any aircraft with dihedral. The effect of dihedral will change based on AoA. In conjunction with 1537, as the AoA and roll increase, the high wing...
  10. J

    Lowering Aileron Effect / Performance at slower speeds?

    where did I say it was? Actually I said the opposite.
  11. J

    Lowering Aileron Effect / Performance at slower speeds?

    1538 would be better. A light airplane like that will "kite" as the nose goes up. That's the reason it loses roll performance. The increased pressure under the wings wants to be equalled. There should be no physical change to the ailerons themselves, I don't imagine that design being tab...
  12. J

    Confused myself...

    CG, yes. Geometry: Elevator arm (distance from CG to elevator) Wing Center of Lift (If wing has more torque than it should, elevator will be diminished) Elevator area Aero Coefficient: Elevator lift CL_de Elevator moment Pitch Moment CMo (if the problem is within a particular range) Pitch...
  13. J

    EGT table 540

    table is useless. map the sea level temperatures then use correction to map all mach. apply a "flow cooler" algorithm and viola.
  14. J

    Flat turns? Rudder with Zero Roll

    zero yaw moment roll rate; plenty of Cn beta weathervane with a healthy dose of beta side force; very stiff roll stability; and zero roll moment yaw rate; it will turn; but like Roy said, it will be a cartoon not possible outside of the sim. In the real world you need a force to turn you...
  15. J

    Jet engine design: drag....questions from my inbox

    I occasionally get questions in my inbox and I feel like some of them would be useful to post publicly. I will try to do so in the future. EVERYTHING described at ISA SL unless otherwise stated. Hello Keith, Coefficients are used anytime the data being analyzed is bound to a set of...
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