I have two Hovey Delta Bird biplane ultralights and a non-enclosed trailer
that I picked up at the same time as I bought the first one.

The aircraft rolled up ramps sideways onto the trailer and clamped into
place and then the tail assembly disconnects at the back of the main wings.
The tail assembly then clamps into place reversed to the direction of travel
with the tail end up near the tow ball. The complete aircraft is exposed to
the elements. The ramps are at different elevations such that the rearmost
wheel (starboard landing gear) is about a foot higher than the front wheel
(port landing gear). This means the wings are at an angle that tends to push
the complete aircraft and trailer down while travelling. A decent sloping
roof on your trailer may add considerable downforce to help you handle the
crosswinds.

The single axle has three leaf springs, two as normal and the third upside
down across the axle from side to side. The weight is shared between the
springs. This is similar to the centre spring front end used on an old
Corolla KE10 from the late sixty's. The cross spring is quite effective in
helping to control the trailer. It is bolted to the frame at the centre and
the flat ends ride on a section of channel welded to the axle so there is a
flat surface to wear. The axle is held in place by the side springs which
are mounted with coupling joints like most leaf spring cars. The side
springs have three leaves and the centre spring has four leaves. I suspect
that about half the trailer weight is supported by the centre spring.

This trailer handles quite well and the second aircraft I towed 300 km
through a back road mountain range to get it home in the middle of a storm.
Although I restricted speed to 70 kmh for most of the trip due to potholes,
and 80 kmh for smoother road stretches, I did get up to 110 kmh for a test
stretch in calmer winds.

I will send a couple of pictures to your email address, and also to anyone
else that would like them, just drop a note here....

Hope this helps,
Peter