Removable Tail on Primera Sailplane

Removable Tail on Primera Sailplane

by Bill Kuhl

Design Considerations

To accommodate airline travel, I needed to come up with a method for creating a removable tail for a Primera two-meter sailplane. In coming up with a method, I had to consider the following items:

It must be light in weight, any extra weight in the tail, takes much more weight in the nose to counter balance.
It must hold the tail with enough strength that flutter is not a problem
The fuselage narrows in the rear and two control rods go through this area.
Anything added must not interfere with the control rods.

Pieces needed to hold stab Pieces needed to hold vertical fin

Vertical Fin Components


Cut out top of fuselage for blind nuts on vertical fin to pass through the top of fuselage.	Balsa supports for plywood that holds blind nuts are glued on the side of the vertical fin opposite the side the control rods pass through. Epoxy blind nuts to plywood pad, and then epoxy plywood to bottom of vertical fin and balsa supports.


	Glue 1/16" plywood pieces on bottom to replace balsa cut out. To mark holes in plywood, I used a length of music wire in cordless drill because I did not have a long drill bit that small. Drill down through the blind nuts into the plywood.

Glue balsa plug on front supports

Vertical fin attached to fuselage

Stabilizer Components

Cut slots on bottom of stabilizer in front for dowels. Sand flat spot on dowel. I was able cut a groove out from the bottom without cutting all the way through. This way the dowels are not visible from the top.

Glue balsa blocks and aluminum tubes with epoxy.

Heads of 4-40 nylon bolts visible from bottom.

The Primera fits easily in a gun case. Used this setup on my trip to the Southwest Classic in Phoenix Arizona. No damage or problem with airline flight although I carried the transmitter as carry on and put a hi-start in the case in its place.

The Primera did very well the first time out, Third Place in 2-meter at the Southwest Classic.