How to calculate the object position in space with altitude?

I have some flight locations, i would like to place a unity objects based on those flight locations. I already calculated spherical location with latitude and longitude without using altitude like this,

for (int i = 0; i < 1000; i++) {
lati = latitude ;
longi = longitude ;
alti = altitude ;

lati = Mathf.PI * lati / 180;
longi = Mathf.PI * longi / 180;
alti = Mathf.PI * alti / 180;

// adjust position by radians
lati -= 1.570795765134f; // subtract 90 degrees (in radians)

// and switch z and y (since z is forward)
float xPos = (radius) * Mathf.Sin (lati) * Mathf.Cos (longi);
float zPos = (radius) * Mathf.Sin (lati) * Mathf.Sin (longi);
float yPos = (radius) * Mathf.Cos (lati);

GameObject flight = Instantiate (aircraft.gameObject, new Vector3 (xPos, yPos, zPos), Quaternion.identity);
}

It gives something like in the image,


Now i need to use the altitude to create the real life like flight position.
How can i achieve this?

Thanks you.​

 

If you want different altitudes, just add radius + altitude, that'll put your flight objects further out from your "earth" center

 

Thanks for the response, I think it's better now but that straight line is something weird. I added radius + altitude to all axis.