King Air C90GTi, Руководство по подготовке пилотов

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The lubricating and scavenge oil pumps are
mounted inside the accessory gearbox, with
the exception of the two scavenge pumps
which are exter nally mounted.
The star ter-generator, high-pressure fuel
pump, N
1
tachometer generator, and other
optional accessories are mounted on pads
on the rear of the accessory drive case. There
are seven such mounting pads, each with its
own different gear ratio.
LUBRICATION SYSTEM
T h e P T 6 A e n g i n e l u b r i c a t i o n s y s t e m h a s
a dual function (Figure 7-13). Its primar y
function is to cool and lubricate the engine
bearings and bushings. Its second function is
to provide oil to the propeller governor and
propeller reversing control system.
T h e m a i n o i l t a n k h o u s e s a g e a r - t y p e
engine-driven pressure pump, oil pressure
regulator, and oil f ilter. The engine oil tank
i s a n i n t e g r a l p a r t o f t h e c o m p r e s s o r
i n l e t c a s e a n d i s l o c a t e d i n f r o n t o f t h e
accessor y gearbox.
The oil tank is provided with a f iller neck
and integral quantity dipstick housing. The
cap and dipstick are secured to the f iller neck,
which passes through the gearbox housing
and accessory diaphragm and into the tank.
The markings on the dipstick indicate the
number of U.S. quar ts of oil less than full
(Figure 7-14).
The engine oil system has a total capacity
of 3.5 U.S. gallons, including the 2.3-gallon
oil tank. Maximum oil consumption is one
quar t ever y 10 hours of operation. Nor mal
oil consumption may be as little as 1 quar t
per 50 hours of operation.
The dipstick will indicate 1 to 2 1/2 quar ts
below full when the oil level is nor mal. Do
not overf ill. When adding oil between oil
changes, do not mix types or brands of oil
due to the possibility of chemical incom-
patibility and loss of lubricating qualities.
A placard inside the engine cover shows the
brand and type of oil used in that par ticular
e n g i n e . A l t h o u g h t h e p r e f l i g h t c h e c k l i s t
calls for checking the oil level, which is re-
quired, the best time to check oil quantity is
shor tly after shutdown, since oil levels are
most accurately indicated at that time.
Oil level checks during preflight may re-
quire motoring the engine for a brief time
for an accurate level reading. Each engine
t e n d s t o s e e k i t s ow n o i l l eve l . T h e p i l o t
should monitor the oil level to ensure proper
operation.
A s p r e s s u r e o i l l e ave s t h e t a n k , i t p a s s e s
through the pressure and temperature-sens-
ing bulbs mounted on or near the rear ac-
cessor y case. The oil then proceeds to the
various bearing compartments and nose case
through an exter nal oil transfer line below
the engine. Scavenge oil retur ns from the
nose case and the bearing compar tments to
the gear-type oil scavenge pumps in the ac-
cessor y case through exter nal oil transfer
lines, and through the exter nal oil cooler
below the engine.
The oil cooler is thermostatically controlled
t o m a i n t a i n t h e d e s i r e d o i l t e m p e r a t u r e .
Another exter nally mounted unit, the oil-
fuel heat exchanger, uses hot engine oil to
heat fuel before it enters the engine fuel sys-
tem. When gas generator speeds are above
72% N
1
, and oil temperatures are between
60 and 70°C, normal oil pressure is between
85 and 105 psi.
KING AIR C90GTi/C90GTx PILOT TRAINING MANUAL
7-12
FOR TRAINING PURPOSES ONLY
7
POWERPLANT