Mid-Continent Instrument MD215 Series Technical Document

Installation Manual and Operating Instructions
Model MD215 Series
Hybrid Counterdrum Altimeter
Mid-Continent Instrument Co., Inc.
dba Mid-Continent Instruments and Avionics
®
9400 E. 34th Street N.
Wichita, KS 67226 Manual Number 9018501
ph [phone] fx [phone] Revision C, October 11, 2017

Manual Number 9018501 2 Revision C, October 11, 2017
FOREWORD
This manual provides information intended for use by persons who, in accordance with current regulatory
requirements, are qualified to install this equipment. If further information is required, please contact:
Mid-Continent Instruments and Avionics
Attn: Customer Service Dept.
9400 E. 34th Street N.
Wichita, KS 67226 USA
PH [phone]
FX [phone]
www.mcico.com
We welcome your comments concerning this manual. Although every effort has been made to keep it free
of errors, some may occur. When reporting a specific problem, please describe it briefly and include the
manual part number, the paragraph/figure/table reference and the page number. Send your comments to:
Mid-Continent Instruments and Avionics
Attn: Technical Publications
9400 E. 34th Street N.
Wichita, KS 67226 USA
PH [phone]
FX [phone]
[e-mail]
All products produced by Mid-Continent Instrument Co., Inc., including those identified as Mid-Continent
Instruments and Avionics or True Blue Power, are designed and manufactured in Wichita, KS, USA.
© Copyright 2016
Mid-Continent Instrument Co., Inc.

Manual Number 9018501 3 Revision C, October 11, 2017
REVISION HISTORY
Revision Date Approved Detail
A 10/30/2015 BAW Initial Release.
B 01/19/2016 BAW Updates for TSO application.
C 10/11/2017 MKN Updated Figure 3.1 with notch.

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TABLE OF CONTENTS
SECTION 1GENERAL DESCRIPTION ..................................................................................6
1.1  Introduction ...................................................................................................................................... 6 
1.2  Technical specifications ................................................................................................................... 7 
 Electrical Attributes ............................................................................................................... 7 
 Physical Attributes................................................................................................................. 7 
 Qualifications......................................................................................................................... 7 
 ARINC data labels................................................................................................................. 8 
 Gillham Code (Encoding Altimeter output)............................................................................ 9 
SECTION 2PRE-INSTALLATION.........................................................................................10
2.1  General Information ....................................................................................................................... 10 
2.2  Unpacking and inspecting equipment ............................................................................................ 10 
2.3  Equipment Location ....................................................................................................................... 10 
2.4  Cable Harness ............................................................................................................................... 10 
 Wire Gauge Selection ......................................................................................................... 11 
 Cable Harness Assembly.................................................................................................... 11 
2.5  Limitations ...................................................................................................................................... 13 
SECTION 3INSTALLATION .................................................................................................14
3.1  General .......................................................................................................................................... 14 
3.2  mounting ........................................................................................................................................ 14 
 Rear Mount Installation ....................................................................................................... 15 
 Front Mount Installation....................................................................................................... 16 
3.3  installation completion.................................................................................................................... 16 
SECTION 4OPERATION......................................................................................................17
4.1  Description ..................................................................................................................................... 17 
4.2  User Interface................................................................................................................................. 17 
 Altitude Display and Units ................................................................................................... 18 
 Pointer ................................................................................................................................. 18 
 Baro Setting and Units ........................................................................................................18 
 Push-button Rotary Knob (Flight Mode) ............................................................................. 18 
 Push-button Rotary Knob (Configuration Mode) ................................................................. 19 
 INOP Flag............................................................................................................................ 19 
 Annunciations (Flight Mode) ............................................................................................... 19 
4.3  Modes of Operation........................................................................................................................ 19 
 Flight Mode.......................................................................................................................... 19 

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 Emergency Mode (for battery-installed units only).............................................................. 20 
 Configuration Mode............................................................................................................. 22 
SECTION 5CONFORMANCE ..............................................................................................24
5.1  Instructions for Continued Air-Worthiness ..................................................................................... 24 
 Pressure System and Altimeter Verification........................................................................ 24 
 Maintenance........................................................................................................................ 24 
 Firmware Updates............................................................................................................... 24 
 Storage Information (for battery-installed units only) .......................................................... 24 
 Battery Maintenance and End of Life (for battery-installed units only) ............................... 24 
 Battery Disposal (for battery-installed units only)................................................................ 25 
 Shipping (for battery-installed units only) ............................................................................ 25 
5.2  ENVIRONMENTAL QUALIFICATION STATEMENT .................................................................... 26 

Manual Number 9018501 6 Revision C, October 11, 2017
SECTION 1 GENERAL DESCRIPTION
1.1 INTRODUCTION
The model MD215-( ) series two-inch Electric Hybrid Counterdrum Altimeter is a pressure actuated,
encoding, sensitive altimeter built to meet or exceed standards set forth in FAA TSO-C10b, C88b, C106,
C179a. The unit provides critical altitude data to the pilot and crew and offers features that enhance
usability, reliability and convenience.
The MD215 provides a needle pointer and two rotating counter drums to indicate altitude up to 55,000
feet and includes an adjustable barometric pressure correction. The user interface features a simple
push-and-turn knob to change the barometric pressure adjustment and address other features. The
flexibility of the MD215 also allows user-configurability to meet a variety of altitude requirements,
including altitude units in both feet and meters and barometric pressure units in both inches of mercury (in
Hg) and millibars (mBar).
The MD215 is designed to be installed in an aircraft cockpit instrument panel and has available options
for either a standard 2-inch ARINC-style front mount or round, bezel-mounted rear mount. Anti-reflective
glass maximizes contrast ratio and provides a clear, efficient display.
The primary input is a pneumatic connection to the aircraft’s static pressure system. Additionally, power is
provided by any input between 10 and 32 volts DC, allowing operation with 14 or 28V aircraft electrical
buses. The configurable lighting input powers an LED backlit display and can accept 5, 14 or 28V lighting
systems.
The MD215 offers excellent reliability based on its solid-state pressure sensor and servo-driven display,
far exceeding the expected life of traditional mechanical altimeters. Versions of the unit are also available
that include an integral and rechargeable Nanophosphate® lithium-ion battery that can power the unit for
one hour if main aircraft power is lost.
The unit has enhanced outputs and communication that provide information to and from the aircraft via a
single ARINC 429 receive bus and an ARINC 429 transmit bus. The input function can receive ARINC
data from the primary flight display system to automatically synchronize the baro adjustment with that
system without redundant pilot intervention. The data outputs provide altitude, baro and other data that
make the unit useful as an independent source of this information as needed on the aircraft. Traditional
encoding outputs (Gillham code) may also be connected to a mode-C transponder or similar legacy
equipment.
The operation and certification of the MD215 make it a great fit for Part 23 and 25 fixed-wing applications
as well as Part 27 and 29 rotorcraft.

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1.2 TECHNICAL SPECIFICATIONS
Electrical Attributes
Characteristics:
Input Voltage: 10-32 VDC
Input Power: (nominal) 3 watts (0.11A @ 28VDC)
(maximum) 9 watts max (when charging)
Battery Capacity (if installed): 3.3 watt-hours
Lighting Input: 5, 14, or 28VDC or automatic photocell control
Input Data: ARINC 429 (see Section 1.2.4)
Output Data: ARINC 429 (see Section 1.2.4);
Gillham encoded data (see Section 1.2.5)
Valid discrete signal to ground; invalid signal is open (pin 2)
Physical Attributes
Characteristics:
Range (altitude): -1,500 feet to 55,000 feet (-450 to 16,900 meters)
Range (baro): 28.00 to 31.00 IN HG (948 to 1050 MBAR)
Weight: 2.0 pounds (0.91 kg)
Dimensions:
(without connectors, mates & knob)
Bezel: 2.27” x 2.27” x 0.23” (HxWxD)
Chassis: 2.18” x 2.18” x 4.63” (HxWxD)
Cover Glass: HEA (anti-reflective) coated per MIL-C-14806
Mating Connectors: 9/16-18 UNJF-3B per MS33649-06 pneumatic fitting (MCI P/N
NY-400-1-6ST)
26-pin D-Sub, MCIA p/n 9018118 (Installation Kit)
Mounting: Front or rear mount, see panel cutout; Figure 3.1 and Figure 3.2
Lighting: Internally lit with white LEDs
Qualifications
Specifications:
Qualification: FAA TSO-C10b, C88b, C106, C179a
Environmental Qualification: RTCA DO-160G
(details listed in Section 5.2)
Complex Hardware Qualification: RTCA DO-254, Design Assurance Level A

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ARINC data labels
All labels are defined as Equipment ID 006 in BNR format.
ARINC 429 Output (Transmit) Speed
Label Description High Low
203 Pressure Altitude X
204 Baro Corrected Altitude X
212 Altitude Rate X
217 Static Pressure, Corrected X
234 Baro Correction (mbar) X
235 Baro Correction (in Hg) X
350 Hardware Version (custom) X
377 Equipment ID (006) X
ARINC 429 Input (Receive) Speed
Label Description High Low
203 Pressure Altitude X X
204 Baro Corrected Altitude X X
234 Baro Correction (mbar) X X
235 Baro correction (in Hg) X X
Table 1.1
ARINC Data Labels

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Gillham Code (Encoding Altimeter output)
Gillham output data (10 bits plus enable) is provided to be consistent with a legacy encoding
altimeter. These outputs are traditionally connected to an ATC Transponder, although they could
be used for other purposes.
The data format is described in the International (ICAO) Standard Code for S.S.R. Pressure
Altitude Transmission contained in ICAO International Standards and Recommended Practices;
Aeronautical Telecommunications, Annex 10, Volume I, Part I, Equipment and Systems. This
document is referenced by SAE AS8003, as required by FAA TSO C88b.
The enable bit (TRANSMIT_ENABLE_N pin 25 listed in the pinout Table 2.1) must be connected
to GND (pin 2 or equivalent) in order to actively update the outputs for normal operation.
Specifications:
Output voltage tolerance 0 – 40V
Current per output 0 – 150mA
Output impedance Modeled as FET in series with 15 ohms to GND
Output voltage Dependent on supply, self-limiting to 150mA
Leakage current 250uA
Maximum rate of change for coded altitude 20,000 ft/min
Maximum switching rate for transmit enable 100 KHz
Table 1.2
Gillham Output Data Specifications

Manual Number 9018501 10 Revision C, October 11, 2017
SECTION 2 PRE-INSTALLATION
2.1 GENERAL INFORMATION
This section contains information and considerations required to prepare for the MD215 installation,
including provided equipment, panel location, wiring and other information.
2.2 UNPACKING AND INSPECTING EQUIPMENT
When unpacking this equipment, make a visual inspection for evidence of any damage that may have
incurred during shipment. The following parts should be included:
a. Hybrid Counterdrum Altimeter MCI P/N 6420215-( )
b. Installation Kit MCI P/N 9018105
i. Electrical Connector Kit MCI P/N 9018118
ii. Pneumatic Fitting MCI P/N NY-400-1-6ST
iii. Screw, #6-32x3/8” MCI P/N 90-612-10011
c. Installation Manual MCI P/N 9018501
Equipment Not Provided
a. Wire, 22AWG (see 2.4.1)
b. Mounting Hardware (Front Mount Installation)
i. ATI2 Instrument Clamp MSP 9962B or similar
ii. Washer, Lock, #6 (optional) Qty (3)
2.3 EQUIPMENT LOCATION
The MD215 Hybrid Counterdrum Altimeter is designed primarily to be installed in the instrument
panel of the aircraft. However, within the limitations of the environmental qualifications, other
locations may be acceptable when considered within the context of the specific application and
with the appropriate installation certification.
Additionally, consider what equipment is behind the panel which may impede the installation of
the MD215. Clearance for the unit as well as its electrical and pneumatic connections and routing
must be allowed. Be aware of routing cables near other electronics or with other wire bundles that
may be susceptible to high energy flow. Avoid sharp bends in cabling or hoses and routing near
aircraft control cables. Also, avoid proximity and contact with aircraft structures, avionics
equipment, heat sources or other obstructions that could chafe or damage wires or hoses during
flight and cause undesirable effects.
2.4 CABLE HARNESS
Construct the cable harness in accordance with the instructions below (see Figure 2.1). Installers
should follow industry-accepted practices regarding aircraft wiring and applicable regulatory
requirements and guidance. The instructions for constructing the cable harness as listed within
this manual were also used to construct the harness during environmental and electrical testing.
Alterations may invalidate environmental qualification and/or performance results. Refer to
Section 2.3: Equipment Location for routing precautions.

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Wire Gauge Selection
Wire gauge should be 22 AWG. Use of PTFE, ETFE, TFE, Teflon, or Tefzel insulated wire is
recommended for aircraft use per MIL-DTL-16878 or equivalent. Additionally, for data signals
associated with ARINC 429 inputs and outputs, shielded twisted pair wiring per M27500 or
equivalent is recommended (pin pairs 3 & 4 and 10 & 11).
Cable Harness Assembly
To assemble the aircraft cable harness and Configuration Module refer to the following
instructions and Figure 2.1:
1. Install a pin/socket as supplied in the Connector Kit using an appropriate crimping tool for
each wire in the aircraft cable harness. Be sure to make the harness long enough to remove
the unit from the front of the panel without stressing the harness (approx. 8” longer than
required to reach the unit connector).
2. Braids from shielded wires should be separated from the wire conductors and pulled back
from the pin/socket termination approximately 2” and gathered together.
3. Route the aircraft wire harness bundle (excluding shield braids) through the appropriate size
strain relief (item #10). The smaller end should extend toward the pins.
4. Insert the pins (Item 4) of the cable harness into the rear of the 26-pin D-Sub connector (Item
3) per Table 2.1 and Figure 2.1 using an appropriate pin insertion tool.
5. Install the D-Sub connector with cable harness attached into the Backshell (Item 6) and
secure with (2) screws (Item 11) and (2) nuts (item #9). Leave screws loose until step 7 has
been completed.
6. Place the D-Sub Slide Lock (Item #2) over the D-Sub connector as shown.
7. Install the D-Sub connector using (2) screws (Item #1), through the D-Sub Backshell (Item
#6), (2) Clamp Shims (Item #5), (2) lock washers (Item #7) and (2) nuts (item #8). Move the
Slide Lock back and forth to verify free movement.
8. Bundle the exposed shield braids and secure them in a ring terminal (not included). Ensure
the right terminal selected will fit the ground lug on the MD215.
9. The completed assembly should look as shown. Verify that the Slide Lock operates freely
and that no wires are pinched, nicked, or otherwise damaged.
10. Verify that power and ground signals are installed appropriately before connecting to the unit.

Manual Number 9018501 12 Revision C, October 11, 2017
Figure 2.1
Cable Harness
Figure 2.2
Assembled Cable Harness
Item Qty. Description
1 2 #2 Latch Screw
2 1 Slide Latch
3 1 D-Sub Connector
4 26 Connector Pin
5 2 Clamp Shim
6 1 D-Sub Backshell
7 2 #2 Lock Washer
8 2 #2 Nut
9 2 #4 Nut
10 1 Strain Relief
11 2 #4 Screw

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Table 2.1
Connector Pinout
2.5 LIMITATIONS
The conditions and tests for TSO approval of this article are minimum performance standards.
Those installing this article on or in a specific type or class of aircraft must determine that the
aircraft installation conditions are within the TSO standards, specification of the article, and
deviations listed below. TSO articles must have separate approval for installation in an aircraft.
The article may be installed only according to 14 CFR Part 43 or the applicable airworthiness
requirements.
Additionally, Mid-Continent Instruments and Avionics submitted for and received a deviation to
FAA TSO C179a with respect to the lithium-ion function of the MD215. In lieu of the MPS
requirements in Section 3 of the TSO which requires compliance to RTCA DO-311, Mid-Continent
tested and complies with the more recent, RTCA DO-347.
When installed, the battery operation will be affected by ambient temperature. If ambient
temperatures are cold enough to limit capacity below the unit’s minimum requirement for one
hour of operation, insufficient capacity will be indicated by an initial power-on test (see Section
4.3.1.5). Additionally, charging of the battery is inhibited below -20°C.
26 Pin External Connector
Pin Pin Description Pin Pin Description
1 +10-32 VDC Input Power 14 Reserved
2 Power Return / GND 15 A2 (Gillham Code)
3 ARINC Out 1B 16 B1 (Gillham Code)
4 ARINC Out 1A 17 B4 (Gillham Code)
5 A1 (Gillham Code) 18 C2 (Gillham Code)
6 A4 (Gillham Code) 19 Lighting Bus Input
7 B2 (Gillham Code) 20 Valid Signal Out
8 C1 (Gillham Code) 21 Reserved
9 C4 (Gillham Code) 22 Reserved
10 ARINC In 1B 23 Reserved
11 ARINC In 1A 24 Reserved
12 Weight on Wheels 25 Transmit Enable (Gillham Code)
13 Reserved 26 D4 (Gillham Code)

Manual Number 9018501 14 Revision C, October 11, 2017
SECTION 3 INSTALLATION
3.1 GENERAL
IMPORTANT: READ THIS ENTIRE SECTION PRIOR TO STARTING INSTALLATION!
This section contains interconnect diagrams, mounting dimensions and other information
pertaining to the installation of the MD215 Hybrid Counterdrum Altimeter. After installation of
cabling and before installation of the equipment, ensure that power is applied only to the pins
specified in the interconnect diagram.
3.2 MOUNTING
Note that front and rear mount options require different versions of the unit. Please order
accordingly.
Note that electrical bonding to the airframe is acceptable but not required in order to meet the
environmental qualifications listed in Section 5.2.

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Rear Mount Installation
Install the MD215 Altimeter within the aircraft in accordance with the aircraft manufacturer’s
instructions and the following steps:
1. Ensure the available instrument panel cutout meets the requirements of the indicator.
See Figure 3.1
2. Secure the indicator to the instrument panel using the screws included in the Installation
Kit, Section 2.2 (or equivalent).
3. Connect static line tube to the pressure port on the back of the altimeter.
4. Connect the electrical connector to the connector on the back of the altimeter.
CAUTION: INSTALL FITTING IN PORT WITH NO MORE THAN 100 IN-LBS OF TORQUE. IF
TORQUE IS NOT SUFFICIENT TO MAINTAIN A SEAL THREAD SEALANT MUST BE USED.
Figure 3.1
Rear Mount Installation

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Front Mount Installation
Install the MD215 Altimeter within the aircraft in accordance with the aircraft manufacturer’s
instructions and the following steps:
1. Ensure the available instrument panel cutout meets the requirements of the indicator.
See Figure 3.2.
2. Secure the instrument clamp to the instrument panel using the screw included with the
clamp.
3. Connect static line tube to the pressure port on the back of the altimeter.
4. Connect the electrical connector to the connector on the back of the altimeter.
5. Slide the instrument into the instrument clamp until the front bezel is seated against the
instrument panel.
6. Tighten the clamp adjustment screws.
CAUTION: INSTALL FITTING IN PORT WITH NO MORE THAN 100 IN-LBS OF TORQUE. IF
TORQUE IS NOT SUFFICIENT TO MAINTAIN A SEAL THREAD SEALANT MUST BE USED.
Figure 3.2
Front Mount Installation
3.3 INSTALLATION COMPLETION
Prior to operating the unit in the aircraft, verify the basic operation of the unit and conduct a
standard leak check of the pitot/static system per the aircraft maintenance manual or industry
practice.

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SECTION 4 OPERATION
4.1 DESCRIPTION
The MD215 Hybrid Counterdrum Altimeter is a stand-alone standby instrument, designed for a 2”
standard opening with available front or rear mounting options. The MD215 features a
counterdrum and needle pointer display with options for feet or meters. Additionally, the manual
or synchronized barometric pressure adjustment can be selected by the user to display either
inches of mercury (IN HG) or millibars/hectopascals (MBAR). The MD215 also features backlit
LED lighting with multiple input formats including 5V, ratiometric (10-32V), or automatic dimming
using the internal photocell. The MD215 will operate with aircraft power of 10-32VDC and has an
optional internal rechargeable lithium-ion battery for emergency operation. The MD215 display,
features and modes of operation are further described in the following section.
4.2 USER INTERFACE
The user interface is comprised of:
Altitude Display and Units
Pointer
Baro Setting and Units
Push-button rotary knob
Annunciations
Invalid (INOP) Flag
Figure 4.1
User Interface
INOP Flag
Altitude Display
Baro Setting
Push Button Rotary Knob
Annunciations
Altitude Units
Baro Units
Pointer

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Altitude Display and Units
The Altitude display is comprised of three rotating drums and two static zero digits. The static
enumeration for single and tens remain at zero at all times. The hundreds and thousands digits,
from 0 to 9, display the active altitude in conjunction with the ten-thousandths digit. The left-most,
ten-thousandths digit also will display a diagonal black and white cross-hatch when the altitude is
between 0 and 9,999. When the altitude is below zero, the left-most digit will display a red and
white cross-hatch symbol.
The units of the numerical display are indicated with a backlit, white LED annunciation in the top
right of the unit display, next to the zero graduation. The altitude units cannot be changed in flight
and must be configured appropriately during installation and/or setup. See Section 4.3.3 for more
information.
Pointer
The pointer performs 360° infinite revolutions and provides resolution beyond the hundreds digit
display of the rotating altitude counterdrum. Each numbered major graduation represents 100
units and corresponds to the hundreds digit of the altitude display. Each minor graduation
denotes twenty units (feet or meters).
The pointer is backlit with white LED lighting.
Baro Setting and Units
The adjustable barometric pressure display is comprised of two single digit and one dual digit
rotating drums. The baro setting allows the user to calibrate the measured static pressure with
respect to the current barometric pressure conditions to accurately display the appropriate
altitude. The baro setting can be made by simply turning the knob clockwise or counterclockwise.
The units of the barometric pressure setting are indicated with a backlit, white LED annunciation
just to the right of the rotating digits. The baro setting units can be changed in flight by simply
pushing the knob and selecting the appropriate units. See Section 4.3 for more detailed
information.
Push-button Rotary Knob (Flight Mode)
The push-button rotary knob performs multiple functions. When in flight mode, rotating the knob
adjusts the baro setting. Pushing the knob allows the user to change the baro setting units.
In configuration mode, the knob has multiple functions. See Section 4.3.3 for more details.

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Push-button Rotary Knob (Configuration Mode)
Press knob while applying power to enter Configuration Mode
Sync/Update symbol turns blue
Continue hold (5+ seconds), blinks blue
Release, blinks white to indicate Config Mode
Rotate right/left to select altitude units
Right/clockwise = feet
Left/counterclockwise = meters
Press knob to confirm FEET or METERS when text blinks
Rotate right/left to select lighting input
Right/clockwise = 5V input
Left/counterclockwise = 14/28V ratiometric
Remove power to exit Config Mode
INOP Flag
The invalid or “INOP” flag appears in the display when the unit has lost all power (external and
internal), when an internal error has occurred, or during a transition between IN HG and MBAR.
When the INOP flag is in view, the information on the altimeter should not be considered accurate
or available for reference. All digital outputs are discontinued when the INOP flag is in view.
Annunciations (Flight Mode)
There are two status annunciators on the unit, the Synchronization (sync) Symbol and the battery
symbol. The Sync Symbol is white when valid ARINC data is being received by the unit and the
baro setting is synchronized with the external data source. The Sync Symbol is off when the baro
setting is in manual mode.
The battery symbol indicates the internal battery status, if installed. It can be green, amber, red or
white. See Section 4.3 for more details.
4.3 MODES OF OPERATION
The MD215 has three modes of operation. They are:
Flight Mode
Emergency Mode (Battery Operation)
Configuration Mode
Flight Mode
The unit will automatically start up in flight mode unless one or more error conditions are
present. No actions are required to initialize or prepare the unit for flight. Once the INOP
flag is lifted, the unit is ready to fly.

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4.3.1.1 INOP flag
If the orange INOP flag is visible, one or more errors are present and the altitude display
should be considered invalid.
4.3.1.2 Barometric Pressure Setting
The barometric setting is changed by rotating the knob while in flight mode. Turning the
knob clockwise will increment the value, while turning counter-clockwise will decrement
the value.
4.3.1.3 Barometric Pressure Units Setting
The barometric units may be changed by pressing the front knob for more than 1 second
and less than 5 seconds, until the units indicator (MBAR or IN HG) starts blinking. The
knob can then be rotated clockwise or counter-clockwise to select the desired unit.
Pressing the knob again will confirm the selection. The orange INOP flag will drop (for
approximately 15 seconds) while the counter drum updates to the new value.
4.3.1.4 Baro Synchronization (optional)
This feature is enabled by connecting the ARINC 429 input to a source providing labels
203 and 204, or 234 or 235. The Sync Symbol (Figure 4.3) will illuminate solid white
when the barometric setting is synchronized to the external reference. Adjusting the baro
setting manually with the knob while synchronized will override the external
synchronization. The external synchronization will again resume if/when the external
reference changes again.
4.3.1.5 Battery Symbol (for battery-installed units only)
Upon initial power on, the unit will run a diagnostic and capacity test on the battery to
determine its status. If the battery is healthy and one-hour of operation is available, the
battery symbol will remain off. If low capacity is detected, the battery symbol will blink
amber. The user can press the knob to acknowledge low-capacity and continue into
Flight Mode. Or, if not acknowledged, the unit will still be available for Flight Mode and
will continue to attempt to charge the battery. If it is sufficiently charged to provide one-
hour of operation, the battery symbol will transition to off.
If the aircraft power is lost or interrupted to the unit, the unit will enter Emergency Mode.
See Section 4.3.2 for more details.
Emergency Mode (for battery-installed units only)
When aircraft power to the instrument has been lost, it will enter Emergency Mode
(battery units only) and be indicated by a green battery annunciation. Internal battery
power will be supplied immediately, without intervention, to maintain normal Flight Mode
operation. If power is restored, the battery symbol will turn off and begin charging battery.
4.3.2.1 Battery Indication
During battery operation, the battery icon is displayed green if more than 10 minutes of
power is available. The battery icon will transition to amber when the available power
drops below 10 minutes. See Table 4.1 for a full list of possible battery conditions.