Frustration !!Water leak at front of trailer!!

[william Haym]

I have a 1993 airstream classic 34' trailer. With a slight water leak near the a/c unit and big leak at thefront window . I checked sealed every seam I could see that could allow rain water to drip above the front center window also (especially front window)
After noticing the leak between the a/c unit and fantastic fan ,I decided
to go on the roof remove the a/c unit and put on a new mounting seal.
It was not a fun job because the bottom drip pan on the a/c unit was sealed with seam sealer instead of the proper mounting gasket.
I'm not sure if airstream did this or done by someone else but with the pan being sealed all around, water would accumulate in the pan and make it leak into the top interior panels of the trailer.
Have any of you seen this type of installation, without the use of a
mounting seal.
Like you input!!