Jesus touches down on Mt of Olives and a great earthquake happens. That is His touchdown return to earth. (Men of Galilee," they said, "why do you stand here looking into the sky? This same Jesus, who has been taken from you into heaven, will come back in the same way you have seen him go into heaven.")
= = = =
The only plausible explanation I know of vis a vis the coming in the clouds as His followers are caught up in the air to meet Him and the Mountain splitting return are that they are two different events.
The traditional view I was reared with is that the in the air occurs at the beginning of the Great Tribulation and the Mountain Splitting one at the end.
Still works for me though I no longer am convinced that we have it even all that specifically figured out to that degree quite so emphatically.
Point #1 - If it is biblically prophesied, then it is not a "secret" return of Christ. It is what it says it is; Christ's participation in the rapture.
Point #2 - there is a way to reconcile these as one, because post-trib dispensationalist folks do so. The rapture would happen during Jesus' descent to touch down on Mt of Olives.
Point #3 - Is anyone surprised that there are differences of opinion when we get down to the specifics of any prophecy? I mean, there are differences of interpretation about plans that one's boss laid out at a staff meeting just last week. With the future, we are left with Jesus' most excellent admoninition: "Watch!"