HSI variables and desired altitude on landing

[newmav]

Hello -

I'm trying to calculate a desired landing path with the HSI

variables (HSI_Horizontal_Needle, HSI_Vertical_Needle) to be

used and reacted upon by an invisible gauge to aid achieving the correct altitude for landing. The problem is that the farther out from the runway you are, the less accurate this is. The value also caps at +1 or -1. Is there a way to calculate feet from the center of the HSI cone (especially the vertical cone) to establish an accurate desired position (altitude)? Or, is there a way to calculate the HSI variables from the list of token vars that you have provided with FSUIPC so that it does not cap at +1 or -1? Thanks for any help.

[Pete Dowson]

I'm trying to calculate a desired landing path with the HSI

variables (HSI_Horizontal_Needle, HSI_Vertical_Needle) to be

used and reacted upon by an invisible gauge to aid achieving the correct altitude for landing. The problem is that the farther out from the runway you are, the less accurate this is.

Isn't that realistic?

Sorry, I don't know all the technicalities of these things, I only provide what's there.

Is there a way to calculate feet from the center of the HSI cone (especially the vertical cone) to establish an accurate desired position (altitude)?

Well, you have the exact Latitude, Longitude and Altitude of both the Glideslope transmitter and the Localiser, and you have the localiser direction and the glideslope angle. All those variables are available. From there it is just a matter of three dimensional trig, isn't it?

Regards

Pete

[newmav]

O.K. thanks! I'll keep plugging away at it.