Been chasing a drip in the hallway skylight and checked the dam that Barth installed as a base for the skylight. Close inspection revealed the aluminum flashing had holes that resulted from water contacting the wood frame and the aluminum - galvanic corrosion from wood in contact with the aluminum. Same process occured in the baggage doors. Removed the skylight and then the flashing to find the flashing was held by rivets (the open end pop rivets) in a bed of silicone! As you know, nothing sticks to silicone so the several layers of roof sealant applied over the years did not stop water infiltration. My solution was to remove the flashing, clean up the wood where it was wet and remove all silicone. Then I purchased copper roof flashing and used Eternabond 2" stips on the roof, set formed strips of flashing - 8 inch wide(2 inches on the roof, 3-1/2" on the wood dam and the remainder folded over the top of the dam under the skylight. I drilled out all the rivets and replaced with closed end pop rivets (waterproof) and applied Sikaflex 715 sealant to the edges and rivet heads. The skylight is screwed to the dam with rusty screws so they were replaced with stainless steel large head screws. You could just use caulk to secure the skylight but stainless won't react agressively with copper and copper won't react with wood. Leaks solved. Total time was three days for both the hallway and shower skylights to be reworked. Do one at a time in case it rains.