Learjet 60 - L, R and STBY Pitot Heat Lights; Oxygen System

Pilot's Manual
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Learjet 60
tains an open circuit for the PITOT HT light as long as sufficient
current is being applied to the associated pitot-static probe heating ele-
ment . In the event of a malfunction in or loss of power to the associated
pilot-static probe heating element, the relay will release and complete
the
PITOT HT light circuit . Illumination
of
the
amber
PITOT HT light,
in the glaresh eld annunciator panel, indicates a malfunction in either
the left, right or standby pitot-static heat system, or that at least one
PITOT HEAT switch is OFF .
LR AND STBY PITOT HEAT LIGHTS (OPTIONAL)
In the event of a malfunction in the picot-static heat system, the appli-
cable amber L, R, or STBY annunciator, and both Master CAUT
lights
will illuminate and flash . Additional pitot-static heat system failures
will cause the applicable individual L, R, or STBY annunciator to
illuminate and both Master CAUT lights to illuminate and flash . When
the aircraft is powered from the
EMER
BUS, the
L
and
R pitot
heat
annunciators will illuminate to notify pilots that only the standby pitot
heat is operational .
OXYGEN SYSTEM
The aircraft oxygen system provides oxygen service for the crew and
passengers . The system consists of the crew and passenger distribution
systems, a
high-pressure oxygen
storage
cylinder, a
shutoff
valve
and
pressure regulator assembly, an oxygen pressure transducer, an oxygen
pressure indicator, an overboard discharge relief valve and indicator, a
passenger oxygen control valve, lanyard actuated passenger mask
oxygen valves, and crew and passenger oxygen masks . Electrical
power to operate the passenger oxygen control valve and oxygen indi-
cator
is supplied through the 7 .5-amp OXYGEN VALVE circuit breaker
on the pilot's circuit breaker panel . Oxygen is available to the crew at
all times and can be made available to the passengers either automati-
cally above 14,500 (±250) feet cabin altitude, or manually at
all
altitudes
through the use of the cockpit controls on the pilot's circuit breaker
panel . The oxygen system is designed for use during emergency
descent to a cabin altitude not requiring oxygen and is not to be used
for
extended periods of
flight
at
cabin
altitudes
requiring oxygen
or as
a substitute for the normal pressurization system . Smoking is prohibit-
ed when oxygen is in use .
6-18
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PM-123
Change 4