AIR DATA SYSTEM
PITOT-STATIC SYSTEM
The pitot-static system supplies pitot and static
air pressure for operation of the airspeed and
Mach indicators, the Mach trim switch, the
Mach warning and overspeed switch, the EPR
system (on airplanes certified for flight in
known icing conditions), the air data sensor
or autopilot altitude controller, and the static
defect correction module. Static pressure is
supplied to the rate-of-climb indicators, al-
timeters, cabin differential pressure indicator,
pressurization control module, outflow valve,
and the cabin safety valve. The equipment in-
stalled varies with airplane model and serial
number. Figure 16-1 shows a typical pitot-
static system incorporating all equipment
which may be installed on the Lear 20.
A heated pitot head is located on each side of
the fuselage just forward of the cockpit (Figure
16-2). Left and right PITOT HEAT switches
are located on the pilot’s subpanel. (See
Chapter 10, “Ice and Rain Protection,” for ad-
ditional information.)
Condensate drains (Figure 16-3), located
near the left and right nose wheel well doors,
are provided for each pilot and static system
on all airplanes SNs 24-138 and subsequent
and all 25 models.
The static systems provide independent sources
of static pressure to the pilot’s and copilot’s
instruments. Each static system has one static
port on each side of the airplane nose (Figure
16-4).
The dual pickups are provided for redundancy
and to reduce sideslip effects on the instru-
ments which use static air.
The left forward and right center static ports are
connected to the pilot’s instruments. The left rear
and right forward static ports are connected
16-3
FOR TRAINING PURPOSES ONLY
LEARJET 20 SERIES PILOT TRAINING MANUAL
FlightSafety
international
Figure 16-3.
Pitot-Static Drains (Typical)
Figure 16-4.
Static Ports (Typical)
Figure 16-2.
Pitot Head (Typical)
