VisualPSX and P3D V4

[Captain_Crow]

Hi dear Hardy and dear Andrej,

i tried to push the famous "B" button in P3D to set the baro to standard as it is set in PSX. Does nothing. So I informed the ATC about this little thing and it was okay... I can live with that...

Best wishes

Steffen

[Hardy Heinlin]

Hi all,

external scenery add-ons use the true altitude from PSX; I don't know if they also take the baro pressure into account when applying the data to external ATC simulations as well. It doesn't matter how you set up your baro pressure for your cockpit instruments.

When you're holding your indicated barometric altitude with a 1013 hPa reference while the nearest airport or local planet area has a different pressure at sea level, your true altitude will disagree with your indicated altitude. If the local true pressure is, say, 997 hPa and you set standard 1013 hPa, your instrument will deviate by ca. 500 ft.

What data source does your external ATC simulation use to determine the aircraft altitude displayed on the simulated controller screen? In real life, when the transponder is in mode C, it always sends the sensed barometric altitude refering to 1013 hPa even at low altitudes; this is the pressure altitude and it's not the same as the true altitude.

At low altitudes there may be another barometric error factor depending on the OAT: The barometric altitude indication will be higher at low temperatures, and lower at high temperatures (barometric navigation is more dangerous in the winter). This effect is simulated in PSX, but not in the other sims. So if you use PSX in an external ATC network with other sims, you should disable the OAT error simulation in PSX. There is a checkbox for this on Instructor > Situation > Aerodynamics. You may hover the mouse over the checkbox to get a tooltip with a description.


Regards,

|-|ardy