E-flite S.E.5a Slow Flyer 250 ARF - Manual (Page 17)

17 E-flite S.E.5a Slow Flyer ARF Assembly Manual
  2. Slide a micro control horn into the slot in the rudder
as shown. Note that the rudder control horn faces away
from the slot in the elevator for the elevator control horn..
  3. Slide the micro control horn backplate onto the control
horn from the opposite side of the elevator as the horn.
Apply a few drops of foam-safe CA onto the backplate to
secure it to the horn.
  4. Repeat Steps 2 and 3 to install the elevator control
horn. The control horn faces down toward the bottom of
the stabilizer/elevator.