SANDIA aerospace SAI-340A Manual

3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
306503-
00
Rev
2
SAI-340A
Pilot Guide

1
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
This document and the information contained herein is the propriety data of SANDIA
aerospace Corporation. No part of this document may be transmitted, reproduced, or copied
in any form or by any means without the prior written consent of SANDIA aerospace.
Due to SANDIA aerospace’s continued product and quality improvement programs,
information contained in this document is subject to change without prior notice Copyright
2016 SANDIA aerospace Corporation, all right rights reserved.
Printed in USA.
Record of Revision
Revision
Date
Description
Approval
1
-
ER
12/8/2017
DRN
-
531 Initial release
Brian Gordon
2
-
ER
5/25/2018
ECN
-
4373
Altitude Bug color change
Brian Gordon

2
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
Table of Contents
Section 1 - System Overview..................................................................................................................3
1.1 Introduction ..........................................................................................................................3
1.2 SAI-340A Product Description..............................................................................................3
1.2.1 Functions........................................................................................................................4
1.2.2 System Interfaces............................................................................................................4
Section 2 - Normal Operation.................................................................................................................5
2.1 Initial Power On....................................................................................................................5
2.2 Thermal Stabilization............................................................................................................5
2.3 Alignment.............................................................................................................................6
2.4 Pilot Display and Controls.....................................................................................................6
2.5 Indicated Airspeed ................................................................................................................7
2.5.1 Indicated Airspeed Limits...............................................................................................8
2.5.2 Over and Under Speed Indications..................................................................................8
2.6 Barometric Altitude...............................................................................................................9
2.6.1 Baro Adjustment.............................................................................................................9
2.6.2 Default Baro...................................................................................................................9
2.7 Instantaneous Vertical Speed Indication (IVSI) .....................................................................9
2.8 Altitude Bug .......................................................................................................................10
2.9 Roll & Pitch........................................................................................................................10
2.10 Slip Indication.....................................................................................................................11
2.11 Brightness Adjustment........................................................................................................11
Section 3 - Abnormal Operation ...........................................................................................................13
3.1 Abnormal Annunciation......................................................................................................13
3.2 Attitude Re-Alignment........................................................................................................13
Memory Error...................................................................................................................................14
3.3 Degraded Attitude...............................................................................................................14
3.4 Transition To and From Battery...........................................................................................14
3.5 Battery Status......................................................................................................................15
3.6 Battery Duration..................................................................................................................16
3.7 Cold Temperature Startup ...................................................................................................17
3.8 Sensor Failure.....................................................................................................................17
3.9 Emergency Shutdown Procedure.........................................................................................17
Section 4 - Operational Limitations ......................................................................................................18
4.1 Operational Limitations.......................................................................................................18

3
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
Section 1 - System Overview
1.1 Introduction
This manual describes the operation of the SANDIA aerospace SAI-340A Attitude
Indicator. It is intended for use by pilots operating the SAI-340A in normal and abnormal
operating conditions.
1.2 SAI-340A Product Description
The SAI-340A Attitude Indicator is a panel mounted attitude, airspeed, altitude, vertical speed
and slip instrument. The instrument is self-contained and directly incorporates all of the sensors
required to measure and display the listed flight parameters.
All information is displayed on a color 3.5” diagonal LCD display in traditional aerospace
symbology. The unit also contains a rechargeable battery capable of providing continued
operation in the event of aircraft electrical failure.
Figure 1 - SAI-340A Overview

4
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
1.2.1 Functions
The SAI-340A performs the following functions:
Display of Indicated Airspeed (Knots or Mph)
Display of Barometric Altitude (Feet)
Display of Roll & Pitch (Fixed Pointer Format, Degrees)
Display of Slip Indication (Degrees)
Display of Vertical Speed Indication (feet per minute)
Pilot Entered Baro Correction (mb or inHg – Configurable Default Value)
Automatic and Manual Backlight Control (%)
Display of Battery Charge Status (% Remaining)
Display of V-Speed Limitations (Colored Bands)
Altitude Bug (Pilot Adjustable)
Various parameters can be configured by the installer (not pilot accessible):
Configuration of Roll & Tilt Offsets
Configuration of Airspeed and Altitude Trim
Configuration of Airspeed Units
Configuration of V-Speeds
Configuration of Baro Units
Configuration of Baro Default Value
Configuration of Battery Type
Enable/Disable Airspeed Tape
Enable/Disable Altitude Tape
IVSI Enable/Disable and Filter Lag
Slip/Skid indicator (Ball, polygon, both)
1.2.2 System Interf ces
Airspeed and altitude are derived from internal pressure sensors that are connected to the
aircraft’s pitot and static lines. Airspeed is determined by the pressure difference between the
pitot and static ports, while altitude is determined by the pressure on the static port. Altitude is
barometrically corrected by the pilot entered baro value prior to being displayed.
Aircraft power is the only electrical interface present. No communication or data interfaces are
provided to other avionic systems in the aircraft.

5
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
Section 2 - Norm l Oper tion
2.1 Initi l Power On
Upon initial power-on, the unit will display the company logo, battery status and software
version. If the battery is not installed, has failed self-test, or is in a low-temperature state, the
battery life will show 0%.
Figure 2 - Power On Screen
2.2 Therm l St biliz tion
On initial power-on, the various internal sensors must thermally stabilize. While this is
occurring, the corresponding indicator area will be covered by a red X. At room temperature,
this process takes approximately 1 minute. At colder temperatures, this may take longer.
If the ambient temperature is below 10°C, the battery will enter a heating cycle and the battery
status icon will be red-X’ed with a BAT HEATING indication as follows:
Figure 3 – Sensor & Battery Stabilization

6
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
2.3 Alignment
On power-up, the unit will perform an initial alignment. The aircraft should not be subjected to
taxing or excessive motions during this process. Alignment is not normally performed during
flight.
During alignment, the aircraft should not be subjected to taxing or
excessive motions.
During alignment, the following message will be presented on the screen:
Figure 4 – Aligning Message
2.4 Pilot Displ y nd Controls
The following shows the on-screen functions and pilot controls once the system has stabilized:
Figure 5 – Pilot Display & Controls
Baro Corrected
Altitude Tape
Baro Corrected
Altitude Drum
Pilot Entered Baro
Correction
Slip / Skid Ball
Indicator
Indicated
Airspeed Tape
Battery Status
Indicator
Attitude Roll /
Pitch
Indicated
Airspeed Drum
Rotary Knob
w/Push
Ambient Light
Sensor Mounting Screw
Hole
Airspeed Limits
Vertical Speed Indicator
and value
Altitude Bug
Altitude Bug
Value
Slip / Skid
Polygon
Indicator

7
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
The Rotary Knob with pushbutton provides the pilot access to all of the interactive functions of the SAI-
340. Figure 6 depicts the pushbutton selection of various functions and Table 1describes the role of the
Rotary Knob in each function
Figure 6 - Pushbutton Controls
Mode
Rotary Knob Function
Idle
Increase/Decrease Baro Setting
Brightness
Increase/Decrease Brightness
Align
n/a
Altitude Bug On
Increase/Decrease Altitude Bug
Table 1 - Rotary Knob Controls
2.5 Indic ted Airspeed
Indicated Airspeed is shown on the left side tape and drum. Airspeeds between 30 to 400 kts (30
to 460 mph) are displayable. If the airspeed exceeds the maximum value, the tape area will be
Red-X’ed. If the airspeed is below 30, the drum display will dash and the tape will settle to 0.
The units for Indicated Airspeed (kts or mph) are set during the installation procedure, and will
match the operating units of the aircraft. Airspeed units can only be configured by approved
personnel and is not pilot adjustable.

8
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
2.5.1 Indic ted Airspeed Limits
Airspeed limits are indicated by means of colored bands and radial lines as follows:
Figure 7 - IAS Limits
The Vmc and Vyse are applicable to multi-engine aircraft only and will not be shown in single
engine installations.
2.5.2 Over nd Under Speed Indic tions
If operation occurs between Vno and Vne, the white surround around the numerical readout will
turn amber. If operation occurs over Vne, or below Vso, the surround will turn red.
Figure 8 - Over and Under Speed Indications
The Under-Speed band and surround coloring is only shown if the aircraft has previously
exceeded Vso. Under-Speed indication is disabled prior to take-off.
Airspeed limits can only be configured by an approved mechanic and are not pilot adjustable.
Vne
Vno
Vmc
Vfe
Vyse
Vso
Vs1
Under
-
Speed
Over
-
Speed

9
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
2.6 B rometric Altitude
Baro Corrected Altitude is shown on the right side tape and drum. The altitude presented is
pressure altitude as measured on the static port, corrected by the currently set baro value.
Altitudes between -1,500 feet and 35,000 feet are displayable. If the aircrafts altitude exceeds
this range, the tape area will be Red-X’ed.
2.6.1 B ro Adjustment
Baro adjustment is performed by rotating the control knob left or right when no menu is selected
(default screen state). The value shown will be in the units that are configured during
installation. Units of inches mercury (inHg), and millibars (mb) are both supported. Baro
Correction from 28.00 inHg to 31.00 inHg, or 948 mb to 1050 mb can be set.
2.6.2 Def ult B ro
The default baro can be selected between Standard (STD), Automatically estimated (AUTO), or
last pilot set value (LAST).
•STD will default to 29.92 InHg (or 1013 Mb).
•AUTO will utilize the airport elevation on the last power-down to estimate a current
baro setting.
•LAST will retain the last pilot entered value.
The baro behavior is configurable to owner preference and can be configured by an approved
mechanic. This setting is not pilot adjustable.
2.7 Inst nt neous Vertic l Speed Indic tion (IVSI)
The IVSI is presented to the pilot using a growing and shrinking bar that gradually appears as
the magnitude of the vertical speed grows. The bar will not appear until the vertical rate excees
±100 Feet/Min. A digital value is also presented to the pilot. The IVSI in the SAI-340A uses
both the rate of altitude change and the internal accelerometer to provide vertical speed with
very little delay. The black area of the box is used for trimming vertical rate and the boundaries
represent ±50 ft/min. The tape itself does not appear until ±100 ft/min is exceeded. The IVSI
can be enabled or disabled during the installation configuration. The display filtering can be
adjusted in the installation configuration pages to slow down the responsiveness.
Figure 9 - Climbing and Descending IVSI

10
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
2.8 Altitude Bug
The Altitude Bug is enabled, disabled and adjusted using the Rotary Knob with Pushbutton.
Figure 6 provides an overview of the pushbutton functionality.
Pressing the pushbutton for 3 seconds allows editing the Altitude Bug (Figure 10.b). The digital
Altitude bug value will appear in the upper right corner of the display while editing the Altitude
Bug. Rotating the knob while editing the altitude bug will modify the Altitude Bug in
increments of 50 feet.
When done adjusting the altitude bug, a short press of the pushbutton will set the bug (Figure
10.c). If the altitude bug is not adjusted for 7 seconds while in the editing mode, the bug will
become set at the current value.
While editing the Altitude Bug, holding the pushbutton down for 3 seconds will disable the
altitude bug (Figure 10.a).
Figure 10- Altitude Bug Modes (a) Disabled, (b) Adjusting/Editing, (c) Enabled)
2.9 Roll & Pitch
Roll is shown in fixed pointer format - the pointer remains in a fixed location relative to the
instrument housing and the roll scale rotates with the horizon. The background blue/brown
horizon is limited such that some ground or sky reference always remains present on the screen.
The pitch ladder and heavy white horizon line will “detach” from the background horizon in
these cases.

11
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
Figure 11 - Example of Detached Horizon Line
Roll and pitch rates are limited to 400 degrees per second and operation throughout all roll/pitch
angles is supported. If attitude is invalid, the center area will be Red-X’ed. No excessive angle
presentations are provided.
2.10 Slip Indic tion
Slip is shown in a format that mimics the mechanical inclinometer (white ball in a glass tube).
The left and right stops represent ± 7 degrees. If the internal slip sensor fails, the area will be
Red-X’ed.
Figure 12 - Slip Indicator Ball / Polygon
2.11 Brightness Adjustment
The screens brightness is either manually or automatically controlled. By default after power-
on, the automatic mode is selected. In the automatic mode, the brightness will be adjusted based
on the ambient light detected by the bezel mounted light sensor.
Pushing the rotary knob displays the brightness adjustment menu. Once displayed, rotating the
control knob left or right will place the unit in to manual mode and increase or decrease the
brightness level. Once adjusted, pushing the knob will clear the menu.

12
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
Figure 13 - Backlight Adjust Menu
After displaying the brightness menu, pushing the rotary knob again without rotating the knob
will leave the unit in the previous operating mode (automatic or manual). Once placed in the
manual mode, automatic mode cannot be re-entered until a power-cycle occurs.

13
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
Section 3 - Abnorm l Oper tion
Figure 14 – Abnormal Operation Indicators
3.1 Abnorm l Annunci tion
Abnormal operating modes and conditions are annunciated by a variety of on-screen indications,
as shown in Figure 14 – Abnormal Operation Indicators.
3.2 Attitude Re-Alignment
In certain abnormal operations, such as aerobics, a manual attitude alignment may be required.
Attitude (roll & pitch) alignment may be performed by momentarily pressing the rotary knob to
present the brightness adjust menu, then pressing and holding the knob in for a few seconds.
This will initiate a re-alignment cycle.
During alignment the aircraft should be held wings-level.
During alignment, the following message will be presented on the screen:
Figure 15 – Aligning Message
Cross Check
Memory Error
Aligning
Battery Status

14
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
Memory Error
On power-on, the unit performs a self-test of the calibration and setup parameters stored in non-
volatile memory. If this test fails, a red MEMORY ERROR message is displayed and the
instrument becomes inoperable. If this occurs, the unit must be returned to the factory for
service.
Figure 16 - Memory Error Message
3.3 Degr ded Attitude
During degraded mode, errors in pitch or roll may be observed during long accelerations or
decelerations, however attitude information is always available - it is never removed or made un-
available.
Errors will not exceed TSO limit specifications. When a cross check message is present the SAI-
340A is considered to be in degraded mode. The TSO tested maneuvers represent typical flight.
Degraded mode may occur if a pilot maintains an accelerated frame of reference (i.e. turns) for
greater than 3 minutes.
Degraded Mode maintains basic attitude performance and is sufficient to maintain positive
aircraft control for VFR and IFR operations.
When operating in the Degraded Mode, a yellow CROSS CHECK message may be displayed on
the screen.
Figure 17- Cross Check Message
Cross Check may occur during extended periods of maneuvering. Reestablishing straight and
level flight allows the unit to reacquire TSO criteria performance. The Cross Check message
will automatically clear once normal operations are resumed.
3.4 Tr nsition To nd From B ttery
The unit will automatically transition to internal battery if the aircraft power drops below
approximately 7 VDC. At this point, one of two operational sequences will occur, depending on
if the aircraft is on the ground or in the air. This logic is tied to the current indicated airspeed as
follows:
•In Flight: If airspeed is above 40 knots, transition will occur to battery with no pilot
action required. Only the yellow ON BATTERY indication will be shown – no other
popup menus or messages will be presented.
•On Ground: If airspeed is below 30 knots, a shutdown timer will be displayed. If the
pilot takes no action, the unit will automatically shut-down in approximately 45 seconds.
This is the normal on-ground shutdown sequence.

15
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
If the rotary knob is pushed to cancel the count-down timer, the unit will remain on and
continue to operate from battery power. The yellow ON BATTERY indication will be
shown.
Figure 18 - On Battery Indication & Shutdown Timer
If aircraft power returns, the unit will automatically switch back to aircraft power and start a
battery charge cycle (if all conditions are satisfied).
3.5 B ttery St tus
Internal battery status is shown in the lower left corner of the screen. When operating on the
internal battery, the colored icon will transition from green, to yellow, to red as the battery
drains. Charge levels above 80% are shown in green, between 25% and 80% is shown in amber,
and levels below 25% are shown in red. The charge is also shown numerically in percent.
Figure 19 - Charge Status Icon
If the battery is charging, a charge indicator will be shown over the colored icon as a small white
lighting bolt. There is a power-on delay of several minutes prior to the charger being internally
enabled. Charging will occur only if the following conditions are detected:
•The battery has passed the power-on self-test
•The battery is sufficiently low that a charge cycle is required
•The ambient temperature is between 0°C and 40°C
•The aircraft supplied voltage is > 10 VDC

16
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
If the battery fails the power-on self-test (or is in a heating cycle), it will be Red-X’ed and no backup
battery capability will exist:
Figure 20 - Battery Not Available Indication
If the battery status icon is Red-X’ed, the battery is not available for use and loss
of aircraft power will result in the unit turning off.
Prior to departure or entry into IFR conditions, verify that the battery is not
faulted (no red-X over the battery icon), and that a charge level of at least 80% is
shown.
3.6 B ttery Dur tion
Battery duration is dependent on several factors; including age of the battery pack, display
intensity setting and ambient operating temperature. With a healthy battery, a minimum of 30
minutes of operation is guaranteed. Typical durations when operating at room temperature and a
reduced display brightness will be approximately 2 hours.
Note that the charge level indicated is an approximation of the remaining capacity of the battery,
and will dynamically adjust based on operating environment and conditions. For example,
diming of the display will extend the battery duration, and thus increase the percent charge
shown. Correspondingly, increasing the display brightness will reduce the battery duration and
thus decrease the percent charge shown.

17
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
3.7 Cold Temper ture St rtup
At operating temperatures below 10° C, the battery pack requires a pre-heating cycle prior to
being brought on-line. The heating time period will depend on the ambient temperature and will
range from a few moments to up to a maximum of 15 minutes (cold-soaked at -20°C).
During the battery heating cycle, the BAT HEATING message is shown in red and the battery
icon is Red-X’ed, indicating battery operation is currently not supported:
Figure 21 - Battery Heating Message
While the battery is heating, operation from battery power is inhibited.
Loss of power will result in the unit shutting down.
Prior to departure or entry into IFR conditions, verify that the battery is NOT in a
heating cycle.
3.8 Sensor F ilure
If any internal sensor fails, the corresponding parameter on the display will remain in the Red-
X’ed state. If this occurs, the unit must be returned to the factory for service.
3.9 Emergency Shutdown Procedure
In the event that the unit requires shutdown in-flight due to improper operation or other failure
mode, perform the following sequence:
1. Remove power from the unit by opening the corresponding circuit breaker.
2. Push and hold the rotary knob for several seconds - this will initiate a manual power-
down sequence.
3. Do not cancel the power-down timer – when the timer expires, the unit will internally
disable the battery and the unit will shut down.
Re-applying external power to the unit will turn the unit back on.

18
3700 Osuna Road NE
Suite 711
Albuquerque, NM 87109
www.sandia.aero
Section 4 - Oper tion l Limit tions
4.1 Oper tion l Limit tions
The following operational limitations apply:
•Geographic limitation: None
•Magnetic field sensitivity: None
•Lightning direct effects sensitivity: None
•Lightning indirect effects sensitivity: Approved for catastrophic functions
•HIRF Susceptibility: Approved for catastrophic functions
•Viewing Angle Limitations: 60° Left / Right, 45° Up / Down
•Displayable Vspeeds: Vne, Vno, Vfe, Vs1, Vso (Vmc, Vyse ME Only)
•Maximum displayable airspeed: 400 Knots / 460 Mph
•Minimum displayable airspeed: 30 Knots / 30 Mph
•Maximum displayable vertical speed range: -5,000 to 5,000 Feet/Min
•Minimum displayable vertical speed range: -100 to 100 Feet/Min
•Maximum displayable altitude: 35,000 Feet
•Minimum displayable altitude: -1,500 Feet
•Maximum configurable baro correction: 1067 mb / 31.50 inHg
•Minimum configurable baro correction: 931 mb / 27.50 inHg
•Minimum operational duration on battery: 30 Minutes
•Maximum roll rate: 400 degrees / second
•Maximum operating G force: 6 G
•Battery operation may be inhibited for up to 15 minutes during cold-starts.
•No operational capability on internal battery is possible if the battery is faulted, as
shown by a Red-X over the battery icon.
•Battery charging is disabled below approximately 0°C and above 40°C, or when power
input is below approximately 11 volts DC.
•In-Flight alignment must be performed with wings-level non-accelerated flight
conditions.
•Airspeed and altitude are derived from internal pressure sensors that are connected to the
aircraft’s pitot and static lines. Airspeed is determined by the pressure difference
between the pitot and static ports, while altitude is determined by the pressure on the
static port. Altitude is barometrically corrected by the pilot entered baro value prior to
being displayed.
NOTE: Approximately nine percent of the population has some sort of color vision
deficiency (what is commonly called “color blindness”). It should also be noted that the
FAA does not test for all potential color deficiencies. (Source TSO-C113a / AS8034)