CESSNA®
MODEL 525B
MAINTENANCE MANUAL
PITOT-STATIC SYSTEM - DESCRIPTION AND OPERATION
(Garmin ADC)
1.
General
A.
This section describes the pitot-static system. The pitot static system has three independent pitot
systems and three independent static systems. There is a pilot pitot-static system, a copilot pitot-static
system, and a standby pitot-static system (refer to Figure 1).
B.
The air data supplied by the pilot and copilot pitot-static systems is shown on the Garmin Integrated
Avionics System primary flight displays (PFDs).
C.
The ESI-1000 (Airplanes -0451 thru -0664) and EFD-750 (Airplanes -0057 and -0665 and On) include
internal pressure transducers to measure static and pitot air pressure inputs. Airframe specific source
error correction parameters are stored in the configuration module and the unit uses the measured
data and error correction to provide a display of attitude, altitude, and airspeed to the flight crew.
2.
Description
A.
The pitot system components include a left, right, and standby system that are divided between the
pilot, co-pilot, and standby respectively. There are three static systems that are also divided between
the pilot, co-pilot, and standby. Each static system has two static ports, with one each on the left and
right sides of the aircraft (refer to Figure 2).
B.
The Garmin GDC 7400 Air Data Computers pilot (ADC 1, left) and copilot (ADC 2, right) supply air
data for flight instrumentation. Each of the two ADCs are found in the forward nose compartment
behind the Nose Radome. ADC 1 is found on left side forward of FS 42.74 at FS 38.13, LBL 11.95
and WL 111.38. ADC 2 is found on right side forward of FS 42.74 at FS 37.98, RBL 11.65 and WL
111.38 (refer to Figure 2).
C.
Each pitot-static system includes a heated pitot tube, related plumbing and an ADC. The standby
system ADC functionality is resident in the ESI-1000 or EFD-750. For the ESI-1000 maintenance
procedures refer to L-3 Communications Electronic Standby Indicator - Removal/Installation. For the
EFD-750 maintenance procedures refer to EFD-750 Electronic Flight Display - Removal/Installation.
Each system includes the components that follow:
(1)
The pilot pitot-static system includes the left ADC, left pitot tube assembly and static ports (left
lower and right upper).
(2)
The copilot pitot-static system includes the right ADC, right pitot tube assembly and static ports
(left upper and right lower).
(3)
The standby pitot-static system includes the ESI-1000 Electronic Standby Indicator or EFD-750
Electronic Flight Display, aft-right pitot tube assembly and static ports (left and right middle).
D.
The Garmin GDC 7400 ADC system measures aircraft static and impact pressure data from pressure
transducers and raw air temperature from an outside temperature probe. The ADCs compute pressure
altitude, vertical speed, airspeed values, air temperature information, and density altitude. Aircraft
specific configuration parameters are stored internally. The ADCs supply the flight crew with the data
that follows in ARINC 429 format:
•
Air Temperature (total air temperature, outside/static air temperature)
•
Corrected static pressure
•
Density Altitude
•
Impact pressure uncorrected
•
Indicated airspeed
•
Mach number
•
Pressure altitude
•
Total pressure
•
True airspeed
•
Vertical airspeed.
E.
The ADCs are RVSM (Reduced Vertical Separation Minimums) capable.
The ADC software
implements airframe-specific Static Source Error Correction (SSEC) equations that correct for
changes in the measured air pressure. These changes in pressure are due to disturbances created
by the aircraft in flight. The ADCs also support external sensor data, such as angle of attack.
34-11-00
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© TEXTRON AVIATION INC.
Feb 23/2022
ICA-525B-34-00004
Form 2261 Rev 1
