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Enstrom TH-28/480 Series Maintenance Manual Supplement 8
G1000H Integrated Flight Deck System
May 14/14
Page 1-8
ICAO 24-bit aircraft address and other aircraft information sent to the Secondary
Surveillance Radar system.
The GTX 33H with extended squitter (ES) enabled provides ADS-B technology that
improves situational awareness and flight safety. With ADS-B capabilities, position,
velocity, and heading information are automatically transmitted to other aircraft and ground
stations. The current ATC system depends on the transmission of interrogations for
pertinent aircraft information at a slower update rate. ADS-B provides immediate
surveillance of air-to-air traffic and aircraft in areas not currently covered by radar.
Ground stations can interrogate Mode S transponders individually using a 24-bit ICAO
Mode S address, which is unique to the particular aircraft. In addition, ground stations may
interrogate a GTX 33H for its transponder data capability and the aircraft's flight ID, which
is the registration number or other call sign. The GTX 33H makes the maximum airspeed
capability (set during configuration setup) available to TCAS systems on-board nearby
aircraft to aid in the determination of TCAS advisories.
The unit features an altitude monitor and TIS traffic advisories. A voice or tone audio output
announces altitude and traffic alerts. The GDU 1040H PFD screen displays the code, reply
symbol, and mode of operation, depending on equipment connections and configuration
selection.
The GTX 33H features multiple transmit/receive ARINC 429 and RS-232 data ports. The
unit concentrates data from three ARINC 429 inputs, gray code, RS-232 input data, and
discrete inputs to the high-speed RS-232 data ports for display on the flight displays.
Although multiple output capability is available, the unit is designed to feed all outgoing
data via RS-232 data ports. Two RS-232 data ports send and receive data to/from the GIA
63H IAU.
The GTX 33H unit is installed in a rack mounted in the upper console. See
Figure 4. Upper
Console Mounted LRUs
.
GRS 77H AHRS with GMU 44 Magnetometer
The Garmin GRS 77H AHRS and GMU 44 Magnetometer are remote mounted devices
that provide flight attitude and heading data for flight instrumentation. With information
available and valid from all sensors, the GRS 77H AHRS provides valid attitude, angular
rate, and acceleration information to the GIA 63H IAU and the GDU 1040H PFD.
An Attitude and Heading Reference System combines the functions of a vertical gyro and
a directional gyro to provide measurement of roll, pitch, and heading angles. The Garmin
AHRS and magnetometer replace traditional rotating mass instruments.
Using long-life solid-state sensing technology, the GRS 77H AHRS and GMU 44
Magnetometer combine 3-axis angular rate, linear acceleration and magnetic field
measurements to create an electronically stabilized AHRS.
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