Arion Aircraft LS-1 Lightning, Pilot Operating Handbook, Page: 116 / 164

Section 7 Lightning LS-1
Description of Airplane & Systems Pilot’s Operating Handbook
Page 7-10 Issue B
CARBURETOR HEAT SYSTEM
Air temperatures inside the carburetor drop during
normal operation due to vaporization of the fuel and
acceleration of air through the carburetor. This
cooling can result in surface temperatures as much as
30°F below the temperature of the ambient air. As a
result, carburetor ice may form on the throttle plate
during periods of operation at low power settings.
Carburetor icing can obstruct airflow and result in
engine stoppage.
The first indication of icing is an RPM drop or
reluctance of the engine to come back to full power
after prolonged period of reduced power. Progressive
icing will cause obstruction of the carburetor, leading
to enrichened mixture and a rough running engine.
The carb heat system directs air from the outer
surface of the muffler into the engine induction
system for the prevention and elimination of
carburetor ice. It should be used at power settings
less than 1800 rpm. If ice is suspected, pull carb heat
to full OPEN. “Pump” the throttle open and closed
several times to break the ice free from the throttle
plate. Leave carb heat on for at least one minute to
melt all residual ice from the induction system.