The main reason that the copper propane lines are on the outside of the
bellyskin is because propane is heavier than air and if a leak were to
develop, the propane would leak down and away from your trailer. Keep your
nose tuned up to the smell of leaking propane. kind of smells like rotten
eggs. You won't mistake it.
Brad Norgaard
Phoenix
'59 Trade Wind Twin
VAC #2699, TCT