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Bonjour à toutes et à tous,
Il semble qu'il y ait un problème sur la puissance des Turboprop, voyez ce qu'en dit Jim Mc Neill; et c'est valable pour tous les autres turboprop...
SHADE TREE MICRO AVIATION NEWSLETTER
Hello, All.
X-Plane V9.2x Engine Performance Bug
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Austin, for whatever reason, made a change to the way that horsepower (HP) is calculated in V9.20 that is adversely affecting the performance of all turbo-prop powered models. He decided that the critical altitude was going to be ignored for all turbines, including turbo-props. This fine for jets, because this is the way they are designed. But unlike turbo-jets and turbo-fans, the vast majority of turbo-prop engines are flat rated. That is, they are physically capable of putting out much more HP than the specific aircraft installation permits. As an example the the thermodynamic HP of the Pilatus' PC-12 P&W engine is 1700 HP but the engine is limited to 1200 HP when installed. The effect of this is to permit full power up to a pre-defined "critical" altitude, at which point power starts dropping off with increasing altitude, thus providing sufficient power for both low altitude and high altitude operations.
The end result is turbo-props no longer have adequate high altitude power to provide book performance. But if you increase the available HP to the thermodynamic value, which you can do by opening the model in PlaneMaker->Standard->Engine Specs, the airplane will dramatically overspeed/overtorque with the application of full power at lower altitudes. Neither situation is realistic but until Austin sees reason, that's the situation.
We have finally convinced Austin to change this system for the release of V9.30, but there's no guarantee that he will be able to do so. In the meantime, we have elected to not to try to adjust all of our models because of the chaos it will cause in making the changes and then changing it again when Austin introduces his new system for controlling HP.
Feel free to modify the HP of any of our turbo-prop models that you intend to use in V9.2x to suit your needs but remember that you may need to adjust them again when V9.30 is released.
If you have any questions, address them to me at papamac@shadetreemicro.com
Jim McNeill (For Peter, Bob, Roger, and Mark - The STMA Crew)
Shade Tree Micro Aviation
Ne vous étonnez donc pas si vos oiseaux n'ont pas la "pêche" :roll: :roll:
Bruno
Il semble qu'il y ait un problème sur la puissance des Turboprop, voyez ce qu'en dit Jim Mc Neill; et c'est valable pour tous les autres turboprop...
SHADE TREE MICRO AVIATION NEWSLETTER
Hello, All.
X-Plane V9.2x Engine Performance Bug
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Austin, for whatever reason, made a change to the way that horsepower (HP) is calculated in V9.20 that is adversely affecting the performance of all turbo-prop powered models. He decided that the critical altitude was going to be ignored for all turbines, including turbo-props. This fine for jets, because this is the way they are designed. But unlike turbo-jets and turbo-fans, the vast majority of turbo-prop engines are flat rated. That is, they are physically capable of putting out much more HP than the specific aircraft installation permits. As an example the the thermodynamic HP of the Pilatus' PC-12 P&W engine is 1700 HP but the engine is limited to 1200 HP when installed. The effect of this is to permit full power up to a pre-defined "critical" altitude, at which point power starts dropping off with increasing altitude, thus providing sufficient power for both low altitude and high altitude operations.
The end result is turbo-props no longer have adequate high altitude power to provide book performance. But if you increase the available HP to the thermodynamic value, which you can do by opening the model in PlaneMaker->Standard->Engine Specs, the airplane will dramatically overspeed/overtorque with the application of full power at lower altitudes. Neither situation is realistic but until Austin sees reason, that's the situation.
We have finally convinced Austin to change this system for the release of V9.30, but there's no guarantee that he will be able to do so. In the meantime, we have elected to not to try to adjust all of our models because of the chaos it will cause in making the changes and then changing it again when Austin introduces his new system for controlling HP.
Feel free to modify the HP of any of our turbo-prop models that you intend to use in V9.2x to suit your needs but remember that you may need to adjust them again when V9.30 is released.
If you have any questions, address them to me at papamac@shadetreemicro.com
Jim McNeill (For Peter, Bob, Roger, and Mark - The STMA Crew)
Shade Tree Micro Aviation
Ne vous étonnez donc pas si vos oiseaux n'ont pas la "pêche" :roll: :roll:
Bruno
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