Date:
11-15-19
Revision: 2
5.7.5-2
VASHON AIRCRAFT RANGER R7 MAINTENANCE MANUAL
GENERAL
The structure of the horizontal stabilizer, elevators, vertical stabilizer, and rudder is of
monocoque design in which the outer skin carries the majority of the load. Ribs and stiffeners
are present but primarily for the purpose of stabilizing the outer skin such that it can carry
greater loads than if it were not supported. Because the outer skin contributes such a large
percentage of the load carrying capability of the fuselage, dents, cracks, or other defects in the
skin must be carefully scrutinized and evaluated in order to ensure that there is no loss in load
carrying capacity.
The majority of the structural parts in the empennage are produced from sheets of inherently
corrosion resistant 6061-T6 aluminum using a CNC turret punch press. The machine cu
t “flat
patterns” are either hydropress formed over dedicated “formblocks” or bent using a press
-brake
machine.
The predominant method for joining parts is with blind rivets although solid rivets and threaded
fasteners (screws and/or bolts and nuts) are used in places where fasteners must be removable
or where high shear strength fasteners are required.
The aircraft is trimmed in flight by changing the position of a tab on the left elevator. The tab is
actuated by an electric servo mounted within the counterbalance arm of the left elevator. The
servo is operated via a rocker switch located on the control stick.
Figure 5.7.5.1 Empennage structure with skin hidden.
