AIR DATA SYSTEM
GENERAL
Air data is provided to the flight instruments
and airplane systems by two air data comput-
ers (ADCs) which receive pitot and static in-
formation from the main pitot-static system.
The ADCs also receive total air temperature
from a dual element temperature probe and
barometric correction inputs via the BARO
set knobs on the corresponding PFDs.
PITOT-STATIC SYSTEM
The primary pitot-static system consists of
two pitot probes (Figure 16-19), located one
on each side of the airplane nose. The open-
ing at the tip of each probe allows impact air
pressure, while holes on the top and bottom of
the probe supply static pressure to the ADCs
(Figure 16-20). A third pitot probe, mounted
above the main probe on the right side of the
airplane, provides impact and static pressure
i n p u t s t o t h e s t a n d b y i n s t r u m e n t g r o u p .
Moisture drains are provided in the pitot/static
lines on the standby system. The main pitot
probes are physically located at the lowest
point of the primary pitot/static system plumb-
ing and do not require moisture drains.
The two main probes and the standby system
probe contain electrical heating elements for
anti-icing. Heating of the elements is controlled
by the L and R PROBES switches on the anti-
ice control panel.
Each pitot-static system (Figure 16-20) is in-
dependent. The left side probe provides pitot-
static source data to the left ADC and the right
side probes (two) provide data to the right
ADC and the standby instrument group. There
are four static sources in the main pitot-static
system, two on each main system pitot-static
probes. The static sources (Static 1 and Static
2) each sense static pressure through two holes
in the probe. Static 1 from the left probe con-
nects with Static 2 on the right probe to pro-
vide static pressure to the left (No.1) ADC.
Static 1 from the right probe combines with
Static 2 on the left probe to provide static in-
formation to the right (No.2) ADC. This cross-
over arrangement reduces system errors.
The pitot source on the standby probe provides
impact pressure to the standby Mach/airspeed
indicator. There are also two static sources on
the standby probe, one provides static infor-
mation to the standby altimeter and the other
provides data to the standby Mach/airspeed
indicator. Two drains for the standby pitot-
s t a t i c s y s t e m ( p i t o t a n d s t a t i c ) a r e f l u s h
mounted on the right side of the airplane just
aft of the nose wheel door (Figure 16-21).
L E A R J E T 4 5
P I L O T T R A I N I N G M A N U A L
16-28
FOR TRAINING PURPOSES ONLY
FlightSafety
international
LEFT SIDE PITOT-STATIC PROBE
RIGHT SIDE PITOT-STATIC PROBES
Figure 16-19. Pitot-Static Probes