OPERATION MANUAL
SILA 450 c
AERO EAST EUROPE
Date 01.09.2015.
Revision 00
Page | 46
AIRPLANE & SYSTEMS DESCRIPTION
Always monitor the air temperature and verify that pulling the WORM selector the air in the
airbox reaches at least 25 °C(expect in case of turbo charged engine).
IN FLIGHT ICE TEST:
Pulling the air selector in WORM position results in a decrease of RPM: no ice
(normal behavior).
Pulling the air selector in WORM position results in a decrease of RPM then a rough
engine behavior and finally an increase of RPM: ICE was present.
NEVER LET ICE TO FORM – ALWAYS PREVENT ITS FORMATION.
Generally the conic air filters are safe from ICE formation due to their hidden position in the
cowling; for the same reason with conic air filters engine performances are averagely
decreased.
AIRPLANE & SYSTEMS DESCRIPTION
The dynamic intake of fresh air make the more performing and this is the reason for the
COLD position of the airbox selector in the normal flight conditions.
Always keep in mind than the air temperature and than the final mixture temperature
passing through the venture system of the carburetor may be so important to reach a
temperature deep of 20 °C and the ice formation is only a matter of concomitant conditions,
so do not be confident: ice formation may occur also with apparently reasonable worm
weather conditions. Do not hesitate to pull WORM air or to perform the ice test at the
minimum doubt! Cold exhaust pipes will no more give worm air: do not risk.
Pull Warm air
always
when rain falls, when misty, when descending, when passing through
clouds.
7.12 CARBURETORS AND PRIMING SYSTEM
The system is consisting in two carburetors which are on the standard engine attached by a
flexible flange. Bowden cables connect throttle and starting device.
When starting the engine operate a few seconds the electric pump (if installed) to ensure
the filling of the carburetors float chambers, pull choke and then start the engine. Throttle
will be in the idle position, soon after engine starts allow the stabilization of the RPM
releasing gently the choke accordingly. Never operate with the choke in, let it in the off
position as soon as it is no more necessary.
Inspection of carburetor floats chambers must be performed often, ask the mechanics to
perform the cleaning and check procedure always when you feel that it is necessary and
especially when often operating with rain or when the aircraft is not kept in hangar. Fuel in
the chambers must always be clean of dirtiness and water. Water is the most common
reason of engine failure during take off together with the fuel valve forgotten in the OFF
position. An accurate worming up pre-flight procedure (with WORM air position in) is
recommended for safety reasons, it will keep you safe from ICE and … fuel valve OFF!...
