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GusRodrigues

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Posts posted by GusRodrigues

  1. Posted

    16 hours ago, twojastara said:

    6. Austin is prepering a new turbo jet engine model.

    Not a new. He is improving the current code for jet engines, and adding a lot of requests, including N1-N2 gearing, i.e. the N1 vs N2 curve.

    He is also expanding the turboprop model to the Free turbine (PT6A) and the Fixed Shafet (Garrett) 

     

    1 hour ago, olderndirt said:

    Just quoting item 4 from "TwoJastara"'s post above.  Granted, there is a smidgen of sarcasm but it's more discouragement at how this sim is making the developers look bad.  This ground handling is becoming an epidemic with disgruntled comments and bandaid fixes from various aircraft owners.  It's great to be a stickler for aerodynamic perfection but, when it don't work, you've got to fix it.

    I would say the X-plane is half responsible to the ground handling issue, and how we control the aircraft in sim is responsible for the other half.

    If you change the default cessna nose wheel to take at least 2.5s to turn to it's maximum, there will be a lot of improvement on how you handle. But crosswinds are indeed, not good.

  4. Posted

    16 hours ago, strider1 said:

    P-Factor should increase with a higher angle of attack ? Combine that with slip stream and you should be stepping on the rudder hard to correct for yaw. Thats my experience in a real 172 !

    I emailed Austin last night about P-Factor and his response was "we do have p factor it will be more accurate in 11.10"

    I did not ask about poor ground behavior, I will leave that up to you guys !

    Austin is aware of a lot of issues were left unchecked from the transition from XP10 to XP11.

    the 11.1 will be a great upgrade for the FM for JetEngines too. But I want a better documentation with planemaker.

  7. Posted

    21 hours ago, jh71 said:

    I know this script, but it is on purpose, it is not a bug...  . 

    On purpose or not, is broken.

    9 hours ago, Novation said:

    Nope, not to me, but maybe I'm stupid? :tongue:

    I'll keep using the script, as long as it works, until its improved offically..... if it is.

    ditto. It is broken. It doesn't matter if is intentional or not, it shouldn't behave like that. I understand time constraint to release RC and final builds of the sim, but cockpit lightning during dusk/dawn is one of the best selling features of the sim. And LR left it (intentionally) broken from day 0.

  10. Posted

    8 hours ago, Jimm said:

    As a community, it would be of great help, if you could elaborate on what is "broken".  The MD-80, as well as the B737 are more complex aircraft (compared to say, the C172SP), as well as a first for LR as default aircraft.  If the issues you have found are indeed in need of fixing, please file a bug report ( http://dev.x-plane.com/support/bugreport.html ) so that the right people can look into this and make the fix.  Statements like the one you made won't help the cause.  Since we are so close to an RTM, it is important that LR be aware of anything that might be lingering and get it fixed. :biggrin:

    It has been done before submitting it here.
     

  12. Posted

    I think if you looked at performance tables for engines, you might see that the behaviour of engines cannot be simplified to "higher TAT as a result of airspeed changes = less thrust". How efficient is an engine at 65kts compared to an engine at 185kts?

     

    If target thrust is achieved by 65kts and the aircraft reaches, say 185kts at 400' what is the actual TAT increase as a result of a 120kt airspeed increase minus the 3 deg C/1000' lapse rate.

     

    N1 as a thrust indicator should not be undervalued. If you saw how EPR is calculated on an RB211, you would realise that a lot of "fudging" is going on, too. You have a single sample of inlet pressure which is compared with several samples of coldstream and hotstream pressures to somehow produce an EPR value consistent for all temperatures/airflows.

    Every "jet engine" is as simple as "higher TAT as a result of airspeed changes = less thrust". High TAT implies there is movement, therefore, there is ram drag.

     

    The Net Thrust is calculated as Gross Thrust - Ram drag, thus if you (and your engines) are stationary (i.e. flight velocity is zero), your Net thrust will be equal to the Gross Thrust. As soon as you start to move, you start to have Ram drag. The faster, the colder and denser the air, the more drag you will have.

     

    I do know how RR measures EPR (a normalized comparison). But N1 is far from being a linear output of thrust.

  13. Posted

    2. With the GE engines that use N1 as primary engine thrust reference, will I see the same decrease? Obviously, N1 is a direct measure of RPM of the big fan so I wouldn't think it would decrease like EPR does when conditions change.

     

    EDIT: I can understand the calculated engine output changing due to environmental factors, but the audible decrease and need for further pitch down to maintain V2 (or V2+X, whichever is higher at that point) is what seems odd to me. I would think the EEC would adjust to maintain the TO thrust rating that's indicated on the EPR display.

    N1 is not at all, by any chance, a thrust reference whatsoever. You may be able to derive the Thrust output through EPR, but never by N1 (i.e if EPR is above 1, there is positive net thrust). N1 is more easy to visually process ("is my engine is pushing air?"), but is by far more complicated to calculate the thrust output from it.

    After you pass your Thrust Reduction Altitude (usually 1,000ft afe), your engine will be throttle back to MAX CLB or MAX CONT.

     

     

    That way seems almost dangerous in the fact that the engines would literally throttle down during an initial climb out killing the climb gradient required and subsequently putting the crew in danger if they lost an engine at the wrong time. Or the fact that they could lose terrain clearance.

    You mean ram pressure rise?

    It is calculated during certification and engineering certification of aircraft performance. They know that the engine will loose thrust due the ram pressure. They even know by how much thrust will be lost.

     

    Assuming there are no flight control issues, the crew has the option of pushing the levers forward. What you probably don't see in your desktop(?) setup is the real position of the thrust levers with the derates in operation. 

     

    If there are possible terrain clearance issues, perhaps these should be considered during your preflight performance calculations. 

     

    Having said this, I'm also confused. You might expect, at 400', with the A/T alive, that the thrust levers would move forward slightly to match the target EPR (not retard). It may be because the FAFCs themselves haven't unlocked. I recall reading (in the dim, dark past) that at least 3 degrees thrust lever movement above 400' is required to unlock the FAFCs. The FAFCs also go into a thrust hold mode. If there is no 3 degree movement, however, they will eventually unlock at a certain height above the departure runway (barometrically computed).

     

    Cheers

    John H Watson.

    I believe that the logic behind the jet engine auto throttle is simple: after the hold mode kicks in during the take-off run, the system will only be able to work again after the Thrust Reduction Altitude. The minimum certified altitude, regulated by FAR part 25, is 400ft.

    If you need any extra bump (windshear? wrong thrust setting during take-off?), you must override the lock before the 400'. That's probably why you should have 3deg of movement of the Thrust lever (have you ever noticed that the auto throttle controls the movement of the thrust levers?) to unlock the fafc.

  15. Posted

    EPR is Engine Pressure Ratio, i.e. the discharge pressure divided by the inlet pressure.

    If there is no extra fuel add to the combustion chamber, there will be no increase in the discharge pressure of the engine, but, as soon as your aircraft starts to gain speed, there will be an pressure rise at the engine inlet, called Ram pressure.

     

     

    a simple calculation of ram pressure at the speed of 180 kias would result in a net loss of close to 0.032 EPR. since you are almost at 1000', there will be further reduction because the drop of pressure with altitude. So it looks like accurate the epr drop.

     

    Set your thrust at static speed (IAS 0) and at sea level pressure. disengage the auto throtle and release the brakes. Don't touch the throttle. try to roll as fast as you can until the runway end. freezes at the end of the runway and compare the epr, n1 and n2.

     

    * epr is discharge/inlet pressure

    ram pressure is 1/2 * density * v²

  16. Posted

    As I know, EPR must be not less than 1.21 if Engine or Wing Anti Ice is activated.

     

    Regards, Sebastian

    EPR is irrelevant for Eng-Wing Anti-Ice

    in descent keep N1 above 55% for use of anti-ice.

     

    I usually cruise at 0.78/0.80

     

    Descent, like most aircraft should be done at cruise Mach speed , changing to IAS 280-320 when appropriate (FL280-300).

    normal econ cruise is .72

    climb and descent is 250-280/.70

    you can achieve a .72 with 2800lbs per engine

  17. Posted

    Gustavo

    What kind of extra tools would you like to see?

    There are already several export scripts for Blender, 3DS MAX and AC3D (Although AC3D is officially supported by LR and Blender is completely free)

    All you would have to do is make the flight model using the included Planemaker software, build a 3D mesh in your 3D program of choice, texture it in Photoshop, Paintshop or Gimp and animate it all in Blender or AC3D.

    The SDK is quite comprehensive. Everything is described, in detail, for you to learn and get started.

    Aircraft wiki...

    http://wiki.x-plane....aft_Development

     

    Scenery Wiki...

    http://wiki.x-plane....ery_Development

     

    SDK for plug ins...

    http://www.xsquawkbo...awiki/FrontPage

     

    And for anything else, the main page...

    http://wiki.x-plane.com/

     

    There are also scenery tutorials...

    http://wiki.x-plane....enery_Tutorials

    No information for network in XP10

     

    constant changes in the .acf and planemaker (recently austin made a change for starter motor).

     

    etc. xp10 is not perfect, but can be as near as possible.

  19. Posted

    I have tried all of those accept the last one but when i say adjust the seat position i mean the actual chair that u see when u look down in the cockpit i need to move that back so i can move the viewpoint back farther with out the viewpoint being behind the actual chair. What i realy want is negative zoom like in FSX.

     

    most planes. i rely just want the ability to change this. negative zoom may seem unrealistic but when i look at where the camera is and how close up the dashboard look it seems like 1X zoom is actualy 1.5X or 2X zoom. Ive flown before in real life and im not nearly that close up.

     

     

    the 10.10 beta (RC) has the option to set some viewpoints and fast scrool through them with the numpad keys.

    set the desired position in vc, hit CTRL + Num Key to save it. just press the Num key to go to that view.

     

    if the default viewpoint is not good for you, just set a new one in the plane maker. but setup new set of views with your numpad is a lot more efficient.

  20. Posted

    Numpad 0 to 9 works.

    I use 8 for visual front view, 7 and 9 to foward left and foward right view (approach) and 4 and 6 to the left and right views, 5 for IFR panel, and 0, 1, 2, 3 as required for each aircraft...

    set the view witch CTRL + numpad key.

  21. Posted

    Might want to check the engines... I know on the C90GTi that the engines are 550hp due to derating... but they'll actually put out a great deal more. It's the instrument red-lines that actually restrict it to 550, not the physical engine. But, that's the GTi... I don't know if it's the same for the C90B.

     

    Is the 'B' even made any longer??

    C90B has a 550SHP engine.

    the B and GTi have been discontinued in production. Actually, only GTx (Pro Line 21 + 750SHP engines (PT6A-135A) + Winglets)

  23. Posted

    That's not possible to do. I can see how it would be easier for the end user, and if we all had identical hardware with identical calibrations, it would be perfect. But there are so many system configurations out there, that it's actually a better idea that the choice is there for the end user to set up the joystick linearity and stability augmentation to their particular tastes.

    I remember having a Microsoft Sidewinder joystick. Played Battlefield 2142 with it and always flew the gunship and managed a 3rd place ranking (for my country) in it. Bought the new Saitek joystick and couldn't fly worth a damn. Crashed every 30 seconds. The difference was like night and day and it took me about 2 weeks to get used to it.

    It is the same for me flying the BF3 Jets vs the BF2 jets with my logitech joystick.

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