Funeral Fly-By

Today i went to an ex-Salvadoran Air Force pilot funeral, as usual, some aircraft flied-by 3 times. The 1st pass with the 4 in diamond formation, the 2nd pass one of them seperates from formation and ascends and the 3rd pass in which only 3 aircraft fly-by.

I was wondering, who started with this tradition (country) about some aircraft flying-by? who got this idea (person)?

Saludos.