Can a conditional sentence begin with "when"? [closed]

I would want to dispel my doubts about the grammaticality of the following sentence:

• When Andrew is there, he will probably have to be helped to climb the stairs.

Some context: I know for certain that Andrew will go there, but I am not sure he will need help.

Is this a conditional sentence? If so, must the dependent clause begin with “if” instead of “when”? And, if I remove “probably”, is the sentence no longer conditional?

Solution 1:

From a comment by Robusto:

It's not a conditional, since when expresses certainty that Andrew will be there. The fact that there is only a probability that he will need help when he is there does not alter the certainty as stated.