In actual operation, the EIRP at the antenna is important as well as antenna radiation pattern close to ground. Also the receiving antenna pattern is important.
The "air loss" or propagation loss , depends not only upon the distance but also on the distance from a (lossy) ground, if there is a vegetation or obstacles along the line of sight, etc. Apply the rule of Fresnel zones if you have such obstacles around.
In general, calculating the line budget for a satellite radio link is easier than for a terrestrial link. In a real situation, surprises do happen.