King Air C90GTi, Pilot Training Manual

Page: 147 / 557

The Propellers section of this chapter pre-
s e n t s a d e s c r i p t i o n a n d d i s c u s s i o n o f t h e
propeller system. Location and use of pro-
peller controls, principle of operation, re-
versing, and feathering are included.
ENGINES
GENERAL
The power plants chosen by Beech designers
f o r t h e K i n g A i r s a r e P r a t t a n d W h i t n e y
Series PT6A free-turbine turboprop engines
(Figures 7-1 and 7-2). The King Air C90GTi
and C90GTx use PT6A-135A engines. The
PT6A-135A engine is Flat Rated to 550 shaft
horsepower.
The engines are equipped with conventional
four-blade, full-feathering, reversing, vari-
able-pitch propellers mounted on the out-
put shaft of the engine reduction gearbox.
The propeller pitch and speed are controlled
by engine oil pressure through single-ac-
t i o n , e n g i n e - d r ive n p r o p e l l e r g ove r n o r s .
The propellers will feather automatically
w h e n t h e e n g i n e s a r e s h u t d ow n o n t h e
ground, and will unfeather when the engines
are star ted.
When reference is made to the right or left
side of the air plane or engine, it is always
looking from the rear to the front.
KING AIR C90GTi/C90GTx PILOT TRAINING MANUAL
7-2
FOR TRAINING PURPOSES ONLY
7
POWERPLANT
Figure 7-1. Powerplant Installation