Sandia Aerospace SAC 7-35 - Manual (Page 13)

Section 2 Installation Considerations
2.1 INTRODUCTION
The SAC 7-35 Airdata Computer enhances installations that include GPS, TWAS, Moving Map
Displays and other avionics that can utilize airdata information. Additionally, the SAC 7-35 is TSO’d
and ETSO’d as an Altitude Encoder for use with transponder systems. The SAC 7-35 provides
standard Gillham Grey Code output on its 15 pin connector (P-101) for use with legacy transponders.
Two independent RS232 corresponding altitude outputs are provided on the 25 pin connector (J-
100). The RS 232 outputs can be used on new generation transponders that accept RS-232 altitude
format or other systems that require corresponding altitude. The P-101 Grey Code connector follows
the standard interconnect format used by most encoder manufacturers. By following this convention,
upgrading to the SAC 7-35 is made easier. If an existing encoder is being replaced, it is important to
check the wiring information before plugging the existing connector into the SAC 7-35.
Two RS232 Airdata and one high-speed ARINC 429 airdata outputs are available from the
SAC 7-35.
Fuel flow data is supported by the SAC 7-35 if pulse type fuel flow transducer(s) are mounted
in the aircraft’s fuel lines. The SAC 7-35 only accepts pulse type fuel information such as that
provided by Flow Scan transducers or through the use af an appropriate converter. If the aircraft is
equipped with a Flow Scan transducer(s) the SAC 7-35 can parallel off the signal line. The SAC 7-
35 must be configured with the transducer(s) K-factor number.
If the aircraft has an altimeter with a 5 VDC baro pot, the SAC 7-35 can use this to provide
corrected altitude output on the ARINC 429 bus. The Garmin-Z output format does not support
Baro Correction information. But, when the baro input is avaiable the data will be included in
the King-D and Garmin-G serial RS-232 airdata outputs.
The SAC 7-35 also incorporates SANDIA aerospace’s exclusive Altitude In-flight Monitoring
(AIM) feature that advises pilots if they deviate from their selected altitude by more than one
hundred feet. The AIM feature can be installed by adding a switch and annunciators to the
aircraft panel.
The SAC7-35 accepts (five wire HSI) heading input in ARINC 407 format. Heading, GPS
ground speed and track inputs are required in order for the SAC 7-35 to calculate winds aloft.
The SAC 7-35 does not require warm up unless the outside temperature is below 20 degrees C.
When warm up time is required, the internal heater is generally capable of warming the SAC 7-
35 from -55 degrees C to operating temperature in less than one minute.
Systems configuration and calibration is accomplished using an installer supplied computer.
The SAC 7-35 is connected to the computer’s 9 pin RS 232 port from the 6 pin DIN connector
located on the front panel of the SAC 7-35.
12