The Mark
21
is
a single engine four-place low wing, retractable
tricycle landing gear
airplane, The design and operation of this
aircraft are conventional with few exceptions, There are no
tricky or complex operational characteristics requiring unusual
or extreme piloting skill. This section
will describe some of
the components of the Mark
2%
and operating details.
PROPELLER
The Mark
2%.
uses an aluminum alloy constant sped propeller
of
74
inch diameter. The pitch of the blades is contro%ld
by
engine oil pressure which acts
to
increase or decrease blade
angle of attack and thereby control engine sped. The propeller
control in the cabin operates
the
propdler governor which
contro%s the oil pressure providd to the propeller hub. The
governor
sating functions to maintain the engine at
a
constant
SF&
by actuating blade angle of ;track. In essence then, the
function of the
propeller control in the cabin
is
to regulate and
maintain the rotational
sped of the engine
at
a desired setting,
The Mark
21
is powered by the Lycoming 180hp 0-360-AID
four cylinder engine. This engine uses
91/98
octane fuel. Four
rubber bushings on the aft side of the engine provide mounting
and vibration isolation. Engine manifold pressure is regulated
5y
the push-pull throttle control on the panel.
The fuel-to-air ratio (mixture) is regulated by the hexagon
shaped push-pull control located between the throttle and pro-
peller controls in the cabin. The Mark
21
engine baffling directs
air flow over the cylinders for cooling in flight. Cowl flaps are
To Next Page
Loading...