Garmin AOA System User manual

AOA System
Owner’s Manual

© 2014 Garmin Ltd. or its subsidiaries. All rights reserved.
This manual reflects the operation of System Software version 2.10 for the GI 260,
or later. Some differences in operation may be observed when Comparing the
information in this manual to later software versions.
Garmin International, Inc., 1200 East 151st Street, Olathe, KS 66062, U.S.A.
Tel: [phone] Fax: [phone]
Garmin AT, Inc., 2345 Turner Road SE, Salem, OR 97302, U.S.A.
Tel: [phone] Fax [phone]
Garmin (Europe) Ltd., Liberty House, Bulls Copse Road, Hounsdown Business
Park, Southampton,
SO40 9RB, U.K.
Tel. [phone] Fax [phone]
Garmin Corporation, No. 68, Zhangshu 2nd Road, Xizhi Dist., New Taipei City
221, Taiwan (R.O.C.)
Tel: [phone] Fax: [phone]
www.garmin.com
https://fly.garmin.com/fly-garmin
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September, 2014 190-01773-00 Rev. A Printed in the U.S.A.

LIMITED WARRANTY
All Garmin avionics products are warranted to be free from defects in materials
or workmanship for: two years from the date of purchase for new Remote-Mount
and Panel-Mount products; one year from the date of purchase for new portable
products and any purchased newly-overhauled products; six months for newly-
overhauled products exchanged through a Garmin Authorized Service Center; and
90 days for factory repaired or newly-overhauled products exchanged at Garmin
in lieu of repair. Within the applicable period, Garmin will, at its sole option, repair
or replace any Components that fail in normal use. Such repairs or replacement
will be made at no charge to the customer for parts or labor, provided that the
customer shall be responsible for any transportation cost. This warranty does not
apply to: (i) cosmetic damage, such as scratches, nicks and dents; (ii) consumable
parts, such as batteries, unless product damage has occurred due to a defect in
materials or workmanship; (iii) damage caused by accident, abuse, misuse, water,
flood, fire, or other acts of nature or external causes; (iv) damage caused by service
performed by anyone who is not an authorized service provider of Garmin; or
(v) damage to a product that has been modified or altered without the written
permission of Garmin. In addition, Garmin reserves the right to refuse warranty
claims against products or services that are obtained and/or used in contravention
of the laws of any country.
THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE EXCLUSIVE
AND IN LIEU OF ALL OTHER WARRANTIES, WHETHER EXPRESS, IMPLIED OR
STATUTORY, INCLUDING ANY LIABILITY ARISING UNDER ANY WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, STATUTORY OR
OTHERWISE. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, WHICH MAY
VARY FROM STATE TO STATE.

IN NO EVENT SHALL GARMIN BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT
OR CONSEQUENTIAL DAMAGES, WHETHER RESULTING FROM THE USE, MISUSE
OR INABILITY TO USE THE PRODUCT OR FROM DEFECTS IN THE PRODUCT. SOME
STATES DO NOT ALLOW THE EXCLUSION OF INCIDENTAL OR CONSEQUENTIAL
DAMAGES, SO THE ABOVE LIMITATIONS MAY NOT APPLY TO YOU.
Garmin retains the exclusive right to repair or replace (with a new or newly-
overhauled replacement product) the product or software or offer a full refund of
the purchase price at its sole discretion. SUCH REMEDY SHALL BE YOUR SOLE AND
EXCLUSIVE REMEDY FOR ANY BREACH OF WARRANTY.
Online Auction Purchases: Products purchased through online auctions are
not eligible for warranty coverage. Online auction confirmations are not accepted
for warranty verification. To obtain warranty service, an original or copy of the
sales receipt from the original retailer is required. Garmin will not replace missing
Components from any package purchased through an online auction.
International Purchases: A separate warranty may be provided by international
distributors for devices purchased outside the United States depending on the
country. If applicable, this warranty is provided by the local in-country distributor
and this distributor provides local service for your device. Distributor warranties
are only valid in the area of intended distribution. Devices purchased in the United
States or Canada must be returned to the Garmin service center in the United
Kingdom, the United States, Canada, or Taiwan for service.
To obtain warranty service, contact your local Garmin Authorized Service Center.
For assistance in locating a Service Center near you, visit the Garmin web site at
http://www.garmin.com or contact Garmin Customer Service at 866-739-5687.

WARNING: For safety reasons, this AOA System’s operational
procedures must be learned on the ground.
CAUTION: This AOA System does not contain any user-serviceable
parts. Repairs should only be made by an authorized Garmin service
center. Unauthorized repairs or modifications could void both the
warranty and the pilot’s authority to operate this device under FAA
regulations.
NOTE: All visual depictions contained within this document, including
screen images of the GI 260 displays, are subject to change and may
not reflect the most current GI 260 software. Depictions of equipment
may differ slightly from the actual equipment.
NOTE: This product, its packaging, and its Components contain
chemicals known to the State of California to cause cancer, birth
defects, or reproductive harm. This notice is being provided in
accordance with California’s Proposition 65. If you have any questions
or would like additional information, please refer to our web site at
www.garmin.com/prop65.
NOTE: This AOA System is non-required and is to be used only as
supplemental information to the pilot. This AOA System is not to be
used or substituted for a certified stall warning system. No operational
credit may be taken for reduced approach speed and shorted landing
distances.
NOTE: The approved Pilot’s Operating Handbook (POH) or Airplane
Flight Manual (AFM) always supersedes this Owner’s Manual.
NOTE: Refer to the AOA System Installation Manual for calibration
instructions.
NOTE: This AOA system is designed to be accurate in the calibrated
aerodynamic configuration. When the aircraft experiences changes in
the airfoil shape (e.g., flap extension or icing accumulation), the AOA
indicator may no longer accurately represent the angle of attack.

Record of Revisions
Part Number Revision Date Description
190-01773-00 A 09/2014 Initial release

190-01773-00 Rev. A AOA System Owner’s Manual 1
AOA System
OVERVIEW
The Garmin AOA (Angle of Attack) System is designed to improve the pilot’s
awareness of the approximate available remaining lift of the aircraft’s wings. The
system calculates the approximate AOA (acute angle between the wing chord line and
the relative wind) using pitot, AOA, and static air pressure inputs.
When correctly calibrated, the system provides a visual approach AOA reference,
as well as increasing caution and warning annunciations as the AOA approaches the
wing’s maximum coefficient of lift (CLmax).
SYSTEM DESCRIPTION
The Garmin AOA System is comprised of three components; the GI 260 Indicator,
the GAP 26 Probe, and the GSU 25 Air Data Computer. The GAP 26 sends pitot and
AOA air pressure to the GSU 25. The GSU 25 measures the air pressure inputs from
the probe and from an independent static source. The GSU 25 then calculates the AOA
information and sends it to the GI 260. The GI 260 displays the AOA information to
the pilot via ten color-coded LED annunciators. When calibrated correctly (refer to
the AOA System Installation Manual for calibration instructions), the system indicates
AOA during critical phases of flight. The system also provides awareness of AOA
trends toward the target AOA for an approach, as well as visual alerting of critical
AOA. When connected to an audio panel or compatible audio system, the GI 260
issues aural alerts of increasing frequency when the system approaches the critical
angle of attack.
GI 260
AOA Indicator
Pneumatic RS-232
GSU 25
Air Data Sensor Unit
GAP 26
Air Data Probe AOA
Pressure
Pitot
Pressure
Static
Pressure
AOA
AOA System

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AOA System Owner’s Manual
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AOA System
GI 260 CONTROLS
NOTE: The TEST and MUTE functions of the GI 260 are described in this
manual. Refer to the AOA System Installation Manual for information on
the CAL (calibration) and SET (alert volume) functions of the GI 260.
MUTE (SET)
Button
GI 260 Controls
TEST (CAL)
Button
SELF TEST
Press the TEST (CAL) button at any time to perform a self test of the GI 260. Upon
successful completion of the self test, all annunciators illuminate and a “Beep - Beep”
audible alert is played.

GI 260 Self Test (Pass)
All Annunciators
Illuminate Beep - Beep

190-01773-00 Rev. A AOA System Owner’s Manual 3
AOA System
A failure is indicated by alternating flashing red chevrons and a “Beep - Beep”
audible alert.

GI 260 Self Test (Fail)
Alternating
flashing red
chevrons Beep - Beep
MUTE
Start-Up
The system is muted by default upon start-up. The system remains muted until 15
seconds has elapsed since start-up and the Angle of Attack reaches the upper yellow
chevron. The first slow audible “Beep-Beep” alert is heard when the upper yellow
chevron annunciator illuminates.
Normal operatioN
Press the MUTE (SET) button to mute the GI 260 audible alert. When muted
manually during normal operation, the audio alert is muted for at least 15 seconds
and remains muted until the upper green bar illuminates for at least five seconds.

190-01773-00 Rev. A
AOA System Owner’s Manual
4
AOA System
NORMAL OPERATION
NOTE: Refer to the approved Pilot’s Operating Handbook (POH) or Airplane
Flight Manual (AFM) for recommended operational procedures.
POWER-UP
The AOA system is ON by default during power-up. During power-up, the
unit cycles its annunciators from bottom to top and back to the bottom. For
the unit to cycle its annunciators it must receive valid AOA data from the GSU
25, determine it has a valid calibration, and pass the unit self test.
GI 260 Power-Up
ARMING OF THE AOA SYSTEM
The AOA system arms automatically when the indicated airspeed exceeds 50
knots. Visual annunciations occur immediately upon arming (if applicable). Aural
annunciations are delayed for 15 seconds after the system is armed.

190-01773-00 Rev. A AOA System Owner’s Manual 5
AOA System
CRUISE CONFIGURATION ANNUNCIATIONS
During flight at low angles of attack (cruise configuration), typically 0-1
annunciators may be illuminated.
GI 260 (Cruise Configuration)
No
Annunciators
Illuminate
APPROACH CONFIGURATION ANNUNCIATIONS
As the angle of attack increases beyond the cruise configuration, the Approach
AOA Reference (green circle) annunciator and the green bar annunciators begin to
illuminate. The Approach AOA is reached when the green bar annunciators adjacent
to the Approach AOA Reference illuminate.
The first slow audible “Beep-Beep” alert is heard when the upper yellow chevron
annunciator illuminates. A fast audible “Beep-Beep” alert is heard when the red
Warning AOA annunciator illuminates.
GI 260 Display
Warning AOA
Approach AOA
Reference
Caution Alert
AOA
Minimum Visible
AOA
Approach AOA

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AOA System
APPROACH AOA REFERENCE
NOTE: For information on calibrating the Approach AOA, refer to the
calibration instructions inAppendix C of theAOA System Installation Manual.
The Approach AOA Reference (green circle) and the adjacent green bar annuncia-
tors should be calibrated to coincide with the published approach speed (if provided),
or the speed upon crossing the runway threshold that is required in order to achieve
calculated (or desired) aircraft landing performance. This speed is typically equal to
or greater than 1.3 times the published stall speed in the landing configuration (Vso)
LOW AOA WITH APPROACH AOA REFERENCE
A low AOA approach is indicated by the illumination of less than four green bar
annunciators and the Approach AOA Reference (green circle) annunciator.
GI 260 (Low AOA with Approach AOA Reference)

190-01773-00 Rev. A AOA System Owner’s Manual 7
AOA System
APPROACH AOA
The Approach AOA is intended to align with the landing reference speed or
threshold crossing speed. In some aircraft the Approach AOA may be consistent with
Vref and equal to 1.3 x Vso (stall speed in the landing configuration).
The Approach AOA is indicated by the illumination of all green bar annunciators
and the Approach AOA Reference (green circle) annunciator.
GI 260 (Approach AOA)
All Green
Annunciators
Illuminate
Approach AOA
Reference
Illuminated
HIGH AOA WITH AUDIBLE ALERT
A high AOA approach is indicated by the illumination of the yellow Caution Alert
AOA bar/chevron annunciators. A slow audible “Beep-Beep” alert coincides with
illumination of the upper yellow chevron.

GI 260 (High AOA)
Yellow
Caution Alert
Annunciators
Illuminate
Beep - Beep
(Slow)

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AOA System
WARNING AOA WITH AUDIBLE ALERT
NOTE: For information on calibrating the WarningAOA,refer to the calibration
instructions in Appendix C of the AOA System Installation Manual.
The first Warning AOA chevron is intended to coincide with the calibrated flap
configuration (typically the landing configuration).
The Warning AOA is indicated by the illumination of the red Warning AOA
annunciators and a fast audible “Beep-Beep” alert.
NOTE: During the landing flare, the AOA and stall warning may not coincide
precisely due to ground effect, mounting of probe, etc.

GI 260 (Warning AOA)
Warning AOA
Annunciators
Illuminate
Beep - Beep
(Fast)
EXAMPLE APPROACH
WARNING: This AOA System is non-required and is to be used only as
supplemental information to the pilot, and may not be used as a substitution
for the certified aircraft stall warning system.
A correctly calibrated AOA System will provide a linear increase in the AOA
indication as the aircraft slows. The bottom red Warning AOA chevron is intended to
coincide with the calibrated flap configuration (typically the landing configuration).
It is recommended to simulate an approach to landing at a safe altitude to ensure
that the lower Warning AOA chevron illuminates concurrently or prior to the first
indication of the certified stall warning horn in the landing configuration.

190-01773-00 Rev. A AOA System Owner’s Manual 9
AOA System
The Approach AOA should be calibrated (refer to Appendix C of the AOA System
Installation Manual) at an acceptable margin above CLmax to fly an approach. As a
starting point, use the aircraft manual to determine the stall speed of the aircraft at the
actual gross weight in the landing configuration. Multiply the calibrated airspeed
by 1.3, then convert from calibrated airspeed to indicated airspeed (if necessary).
Once the AOA angles have been calibrated, they will be accurate in the calibrated flap
configuration, at any gross weight or altitude, every time.
Example Indications for a Typical Decelerating Approach and Flare
Runway
Numbers
DOWNWIND
FINAL
BASE
Runway
Cruise FinalDownwind Base
50 ft Over Landing
Threshold
(Approach AOA)
50 feet
Threshold
FLARE
Linear Increase in the AOA as the Aircraft Slows

 




 




190-01773-00 Rev. A
AOA System Owner’s Manual
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AOA System
ABNORMAL OPERATION
AOA SYSTEM FAILURE
I n the event that the GI 260 or the AOA system is malfunctioning, the unit can be
powered-down by pulling the associated circuit breaker.
NUISANCE ALERTS
In the event that the AOA System is providing nuisance alerts, press the MUTE
(SET) button to mute the GI 260 audible alerts. The audio remains muted for at
least 15 seconds and remains muted until the upper green bar illuminates for at
least five seconds.

Garmin International, Inc.
1200 East 151st Street
Olathe, KS 66062, U.S.A.
Toll free: 800.800.1020 or
866.739.5687
p: 913.397.8200
f: 913.397.8282
Garmin AT, Inc.
2345 Turner Road SE
Salem, OR 97302, U.S.A.
Toll free: 800.525.6726
p: 503.391.3411
f: 503.364.2138
Garmin (Europe) Ltd
Liberty House, Bulls Copse Road
Hounsdown Business Park
Southampton, SO40 9RB, U.K.
Toll free (within U.K.) 0808.2380000
p: 44/0870.8501241
f: 44/0870.8501251
Garmin Corporation
No. 68, Jangshu 2nd Road
Shijr, Taipei County, Taiwan
p: 886/2.2642.9199
f: 886/2.2642.9099
www.garmin.com
190-01773-00 Rev. A
© 2014 Garmin Ltd. or its subsidiaries