Flight Controls - Cessna 172SPHUSR05 Pilot Operating Handbook

SECTION 7
AIRPLANE SYSTEMS DESCRI PTION
&
The empennage (tail assembly) consists of a conventional verti­
cal stabilizer, rudder, horizontal stabilizer, and elevator. The vertical
stabilizer consists of a spar, formed sheet metal ribs and reinforce­
ments, a wraparound skin panel , formed leading edge skin and a
dorsal. The rudder is constructed of a formed leading edge skin and
spar with attached hinge brackets and ribs, a center spar, a wrap
around skin , and a ground adjustable trim tab at the base of the
trailing edge. The top of the rudder incorporates a leading edge ex­
tension which contains a balance weight.
The horizontal stabilizer is constructed of a forward and aft spar,
ribs and stiffeners, center, left, and right wrap around skin panels,
and formed lead i ng edge skins. The horizontal stabi lizer also
contains the elevator trim tab actuator.
Construction of the elevator consists of formed leading edge
skins, a forward s par, aft channel, ribs, torque tube and bellcrank,
left upper and lower "V" type corrugated skins, and right upper and
lower "V" type corrugated skins i ncorporating a trailing edge cutout
for the trim tab. The elevator tip leading edge extensions
incorporate balance weights. The elevator trim tab consists of a
spar, rib, and upper and l ower "V" type corrugated skins.

FLIGHT CONTROLS

The airplane's flight control system (Refer to Figure 7-1 ) consists
of conventional aileron, rudder, and elevator control surfaces. The
control surfaces are manually operated through cables and
mechanical linkage using a control wheel for the ailerons and
elevator, and rudder/brake pedals for the rudder.
TRIM SYSTEM
A manually operated elevator trim system is provided ( Refer to
Fig u re 7-1 ). Elevator 'trim ming is accomplished through the elevator
trim tab by util izing the vertically mounted trim control wheel i n the
cockpit. Forward rotation of the trim wheel wil l trim nose down ;
conversely, aft rotation will trim nose up.
7-6
CESSNA
MODEL 1 72S
Jul 8/ 8