SAFE FLIGHT SCc Angle of Attack User manual

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PROPRIETARY NOTICE
This document contains proprietary information and covers
equipment in which Safe Flight has proprietary rights.
No data contained herein may be duplicated, used, or
disclosed, in whole or in part, for any purpose, without the
express written permission of Safe Flight Instrument
Corporation.
Safe Flight Instrument Corporation expressly reserves all
rights, including all rights of patent and copyright protection.
© SAFE FLIGHT INSTRUMENT CORPORATION
2016

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TABLE OF CONTENTS
Para. Description Page
None Title Page......................................................................................................................1
None Revision Notice.............................................................................................................2
None Proprietary Notice .........................................................................................................3
None Table of Contents..........................................................................................................4
System Description.......................................................................................................51.01.1 SCc................................................................................................................................5
1.2 System Components.....................................................................................................5
1.3 Theory of Operation......................................................................................................7
1.4 Scope............................................................................................................................8
1.5 Limitations.....................................................................................................................8
1.6 Specifications................................................................................................................8
Installation, Adjustment and Functional Check.............................................................92.02.1 Installation Procedure ...................................................................................................9
2.2Lift Transducer Wing Position.......................................................................................9
2.3 Doubler Installation .......................................................................................................9
2.4 Indexer Computer .......................................................................................................10
2.5 System Wiring.............................................................................................................13
2.6 Lift Transducer Installation..........................................................................................13
2.7 Ground Functional Test ..............................................................................................13
Flight Check and Adjustment......................................................................................143.03.1 Background.................................................................................................................14
3.2 Transducer Location Verification Flight.......................................................................14
3.3 In-Flight Final Calibration Adjustment.........................................................................15
3.4 Final Lift Transducer Installation.................................................................................16
3.5 Precautions .................................................................................................................16
3.6 Weight and Balance....................................................................................................16
Troubleshooting ..........................................................................................................164.04.1 System Removal.........................................................................................................16
4.2 Failure Modes .............................................................................................................17
4.3 Instructions for Continued Airworthiness ....................................................................17
User Manual................................................................................................................185.05.1 General .......................................................................................................................18
5.2 System Display ...........................................................................................................18
5.3 Pre-Flight Ground Check Procedure...........................................................................18
5.4 Additional Button Press Functions..............................................................................19
5.5 Takeoff and Climb.......................................................................................................20
5.6 Cruise..........................................................................................................................20
5.7 Landing Approach.......................................................................................................22
5.8 Low Airspeed Awareness (LAA) .................................................................................23

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TABLE OF CONTENTS (continued)
Para. Description Page
None Appendices .................................................................................................................24
Appendix A:Method to Determine Lift Transducer Placement
Appendix B: Flight Check Data
Appendix C: Lift Transducer Adjustment Based on Indication

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SYSTEM DESCRIPTION1.0
SCc1.1
The Safe Flight SCc Angle of Attack (AoA) System is an accurate wing lift measuring and
display system designed as an aid to help the pilot achieve consistent takeoff, climb, cruise
and landing approach performance. Using a wing leading edge flow measurement device,
the SCc AoA System precisely senses the flow field about the wing’s leading edge. The SCc
AoA indication is accurate regardless of aircraft weight, wing loading, turbulence or wing flap
configuration. This system provides the pilot with AoA-based guidance for high-lift operational
conditions including normal and short-field takeoff, Best Rate (Vy) and Best Angle (Vx) of
climb, wind-compensated Long Range Cruise (LRC), maximum endurance, normal and
short-field runway performance, and Low Airspeed (high AoA) Awareness (LAA).
System Components1.2
Lift Transducer Indexer Computer
The SCc AoA System consists of a wing leading edge mounted Lift Transducer and a
glareshield mounted Indexer Computer.
The installation parts are listed in Table 2. Table 3 lists standard hardware suggested for the
installation.
Table 1: SCc Included Components
COMPONENT PART NUMBER
WEIGHT
(lbs.)
VDC AMP
Installation Instructions and User Manual 56201-2_B
Quick Reference Guide
56202-2_A
Wiring Schematic Textron SC-C
70308800-15_A
Lift Transducer
C-14007-1
0.3
Indexer Computer
C-14061-1
0.2
10-32 V
0.20A @ 28V

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Table 2: Installation Parts
Description
Hardware
Part Number
Quantity
Doubler
Lift Transducer Doubler
Plate
3704-223-1 1
Label Advisory Placard 55562-1 1
Backup Disc Assembly 1504-114-4 1
Ball Assembly 1504-128-4 1
Base & Spring Assembly 1504-126-4 1
Cover 1504-229-4 1
Cable Assembly, CAT5e 8 ft. length male to male 3704-150-2 1
Cable Assembly, CAT5e, Extension 8 ft. length male to female 3704-160-1 1
Table 3: Standard Hardware Needed
Description Part Number
Quantity
Needed
Flat Head 100 deg 6-32x1/2 MS34693-C28 3
Pan Head 6-32x1/2 MS51957-30 5
Nut, blind rivet NAS1329A06-75 4
For all standard hardware, equivalent components may be used. See AC 43-13 for guidance on the use
of equivalent parts. Any substitution is the sole responsibility of the installer.
Listed below are the tools needed to complete the SCc installation.
•Proper sheet metal cutting equipment
•Fine tipped pen
•Drill and drill bits
•Rivet nut installation tools
•Phillips head screwdriver
•Combination square with level
•(2) Plumb lines

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Theory of Operation1.3
As the aircraft wing moves through the air it divides the air mass. At the center of this divided
airflow is a narrow region known as the stagnation point. The location of the stagnation point
uniquely represents the wing’s AoA.
As the AoA increases, the leading edge stagnation point moves aft chordwise on the lower
surface of the wing. The Lift Transducer senses the location of the stagnation point by means
of a spring-loaded vane. The Lift Transducer is designed to detect the location of the
stagnation point and relays this signal to the Indexer Computer.
The location of the Transducer on the wing is carefully chosen so that the sensed airflow is
optimized for all of the high lift performance regimes of the aircraft. These include near
maximum wing lift during normal and short-field takeoff and landing operations and the AoA’s
associated with optimized long range cruise and maximum endurance.
Decreasing the AoA of the wing moves the stagnation point forward (UP); increasing AoA
moves it aft (DOWN) as shown below. At a maximum aft position, wing lift rapidly decreases,
which is the AoA at which the stall occurs.
In the Aircraft Flight Manual (AFM) or Pilot Operating Handbook (POH), the speed at which
the stall occurs is given in terms of indicated airspeed. The stall speed varies with aircraft
gross weight, center of gravity, bank angle, maneuvering load and wing flap configuration. As
each of these is reflected by the movement of the stagnation point, the Lift Transducer
senses the wing’s leading edge flow field giving an accurate and repeatable indication of the
AoA.
The AoA, measured relative to stall, is displayed on the color-coded LEDs (green/amber/red)
on the Indexer Computer, which is mounted vertically on the instrument panel glare shield. A
pilot-selected reference mark may be set for the desired operational reference.
For Low Airspeed Awareness (LAA), high-AoA trend information supplements the aircraft’s
stall warning system by the display of two blinking red LEDs and a ‘Geiger counter’-like audio
output to the cockpit speaker and/or pilot headset. The audio begins when two amber LEDs
are illuminated and increases frequency as the AoA approaches stall.

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Scope1.4
The system meets the requirements of FAA Memo AIR100-14-110-PM01, dated February 5,
2014, regarding the Approval of Non-Required Angle-of-Attack (AoA) Indicator Systems.
These installation instructions become the approved data necessary for the installation of the
SCc.
1.4.1 These installation instructions are FAA Approved Data to be utilized only for the installation of
the AoA system described herein on aircraft certified under 14 CFR Part 23 (or
predecessors). Provided all of the requirements of section 2.0 of this document are met, no
further FAA approval is required for the installation of this AoA system on a Part 23 aircraft.
If the limitations of section 2.0 are not met, further FAA approval may be required.
1.4.2 These installation instructions are only approved for the aircraft models listed: Cessna 172,
182 and 206.
Limitations1.5
1.5.1 The Safe Flight SCc System is non-required and is to be used only as advisory information to
the pilot. The system cannot replace the certified stall warning system. No performance credit
can be taken from the system, such as reduced approach speeds, reduced takeoff or landing
distances, etc.
1.5.2 The aircraft Pilot Operating Handbook or Aircraft Flight Manual always supersedes this
system’s manual.
1.5.3 SCc cannot be installed in a Commuter or Transport category airplane.
Specifications1.6
Operational Temperature Range
-45°C to 70°C (DO160G Level B2)
Survival Temperature Range
-55°C to 70°C (DO160G Level B2)
Operating Humidity Range
DO160G Level B (95% max.)
Operating Altitude Range
0 – 25,000 ft. (DO160G Level B2)
Operating Airspeed Range
VS0 to ~2 x VS0
Precipitation
No limitations
Icing
Not for use in icing conditions
Deicing Fluids
No limitations
Emissions of RF Energy
DO/160G Category M
Voltage Operating Range
10-32 V

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INSTALLATION, ADJUSTMENT AND FUNCTIONAL CHECK2.0
Installation Procedure2.1
The installation of the SCc AoA System requires installing the Lift Transducer on the leading
edge of the wing, installing the Indexer Computer, and system wiring. After installation, both
a ground functional and a flight check are performed. The data from the flight check is to be
recorded in Appendix B. If needed, Appendix C provides a guide for adjustment of the Lift
Transducer mounting plate on the wing to adjust the results obtained from the flight test data.
Lift Transducer Wing Position2.2
The following is a procedure for finding the initial location for the mounting of the Lift
Transducer.
The installation of the SCc Lift Transducer should typically be made on the wing opposite to
the existing stall warning device, at the same or close to the same spanwise position. This
location may be varied in order to facilitate the ease of installation access of the wing
components through an existing wing panel access.
The SCc System cannot be used as a replacement for or
modification of an existing FAA approved Stall Warning System.
NOTE
The location should be clear of any internal interference from ribs and other aircraft structure.
Be sure to note locations of pitot lines, wiring, fuel tanks, fuel lines, and other aircraft
hardware to avoid any interference.
The Lift Transducer is to be mounted initially at 1% chord. Use the method described in
Appendix A to determine the proper location for mounting the Lift Transducer. Place a mark
on the wing at this location. This will be the center of the cutout for the Lift Transducer
Doubler.
Doubler Installation2.3
Using the Doubler provided as a template, contour and temporarily tape the Doubler to the
leading edge of the wing. Align the center of the cutout of the Doubler with the leading edge
1% chord mark. Using a fine-tipped marker, trace the outline of the Doubler cutout so as to
mark the area of aircraft skin that is to be removed from the wing’s leading edge for the
installation of the Lift Transducer.
Remove the Doubler and reserve it for installation inside the wing.
Cut through the wing, as outlined by the Doubler cutout, to create the Lift Transducer
mounting hole.
Through a nearby access panel, insert the Doubler into the wing and align it with the leading
edge wing hole. Bend the Doubler to match the wing contour at this position. Rivet the
Doubler to the inside wing surface using appropriate rivets, in accordance with AC 43-13.
Ensure that sufficient space is left for rivnut installation.
Place the Lift Transducer in the hole, forming the Mounting Plate to the contour of the leading
edge. As with the Doubler, the Lift Transducer Mounting Plate has been contoured to the
approximate curvature of the wing’s leading edge. Final adjustments to the Lift Transducer
mounting plate will be made during the installation on the wing.