King Air C90GTi, Pilot Training Manual

Page: 232 / 557

ENGINE AUTO IGNITION
SYSTEM
The engine auto ignition system provides
automatic ignition to attempt a restart should
a flame-out occur. Once ar med, the system
e n s u r e s i g n i t i o n d u r i n g t a ke o ff , l a n d i n g ,
turbulence, and penetration of icing or pre-
c i p i t a t i o n c o n d i t i o n s . S h o u l d i c e o r r a i n
cause an engine flameout, auto ignition will
automatically reignite the engine.
The switches used to arm the auto ignition
system are located on the pilot’s left subpanel,
above the ice vane switches and just to the
left of the control column (Figure 10-14). The
system is activated by moving the switches
into the up or ARM position. Each switch
must be lifted over a lock-out barrier before
it can be moved into, or out of, the ARM po-
sition. This lever-lock feature prevents in-
advertent movement to the OFF position.
If, for any reason, engine torque falls below
four hundred foot-pounds, electrical power
is provided to energize the engine igniters.
As this happens, the g reen IGNITION ON
annunciator on the panel will illuminate, in-
d i c a t i n g t h a t t h e i g n i t i o n s y s t e m i s e n e r -
gized. During ground operation, the system
should be tur ned off to prolong the life of
the igniter units.
ENGINE AIR INLET LIP HEAT
The lip around each air inlet is heated by
hot exhaust gases to prevent the for mation
o f i c e d u r i n g i n c l e m e n t we a t h e r ( Fi g u r e
10-15).
A scoop in the left engine exhaust stack de-
flects the hot exhaust gases downward into
the hollow lip tube that encircles the engine
air inlet. The gases are expelled through a
line into the right exhaust stack, where they
move out with the engine exhaust gases.
Heat will flow through the inlet whenever the
engine is r unning.
KING AIR C90GTi/C90GTx PILOT TRAINING MANUAL
10-13
FOR TRAINING PURPOSES ONLY
10
ICE
AND
RAIN
PRO
TECTION
Figure 10-14. Engine Auto Ignition
Switches
EXHAUST GASES
FLOW DIRECTION
ENGINE EXHAUST
STACK
PITOT COWLING
Figure 10-15. Engine Air Inlet Lip Heat