I am trying to add how many seat hours per equipment type each person has.
Which formula should I use? I've tried several and I get errors.

Example:

Crane type 3&4: how many times they have used this type of crane. I used
this formula but get 0 value instead of "3", which is the number of times in
the selection that the person used this specific type of equipment.

=SUMIF(D6:D41,"if(d6:d41{=3},{=4},1")

I am trying to assign a value of 1 to each cell that has a 3 or a 4 in it in
that specific range, so that when I add the range it will calculate how many
times they used either crane #3 or crane #4.

Thanks