Judging distance in formation flying?

[Reverze]

Hi everybody

So me and robart are often flying together to practice procedures as stipulated in the -3. Currently we're doing lots of formation flying and turns. The -3 tells us how much seperation we should keep, for instance 6000-9000 ft in the line formation. Of course I understand these distances are a general ballpark, and to be adjusted as the situation requires.

Can any of you give us any tips or tricks to help us judge the distance between us? Using a TAD hook gives a general idea in NM to help us get a feel for it, because it's quite hard to judge a distance like that especially for metric-oriented people. Obviously using the TAD like this is not something to ever use in an actual mission, it's only as a reference to get a bit of recognition memory. It's hard to get a feel for the distance without having any reference, except maybe the ground: "ah we're 7000 ft in the air, the ground looks about as close as my wingman, therefor he must be about 7000 ft off my wing". The ground seems like a terrible reference.