PNP Flex Innovations Twin Otter 80E User manual

DESIGNE
D BY:
www.flexinnovations.com

1
BEFORE CONTINUING WITH THIS INSTRUCTION MANUAL OR ASSEMBLY OF
YOUR TWIN OTTER 80E, PLEASE VISIT OUR WIKI SUPPORT SITE FOR THE LATEST
PRODUCT UPDATES, FEATURE CHANGES, MANUAL ADDENDUMS AND
FIRMWARE CHANGES FOR BOTH YOUR TWIN OTTER 80E AND THE INSTALLED
AURA 8 ADVANCED FLIGHT CONTROL SYSTEM.
wiki.flexinnovations.com/wiki/TwinOtter_80E
wiki.flexinnovations.com/wiki/Aura

2
TABLE OF CONTENTS
Introduction 2....................................................................................................
Includes/Requires 2.........................................................................................
Specifications 3.................................................................................................
Completion Items 3.........................................................................................
Optional Items 3...............................................................................................
Replacement Parts Listing 3.........................................................................
Special Language Definition 4.....................................................................
Important Information Regarding Warranty 4.......................................
Safety Warnings and Precautions 4............................................................
Low Voltage Cutoff4.......................................................................................
Before you Begin 5...........................................................................................
Battery Charging Guidelines 5.....................................................................
Main Landing Gear Installation 6................................................................
Nose Gear Installation 7.................................................................................
Tail Installation 8...............................................................................................
Horizontal Stabilizer Installation 9.............................................................
Motor Installation 10.......................................................................................
Main Wing Installation 11..............................................................................
Main Wing Installation (continued) 12.....................................................
Night Twin Otter 80E LED Connections 13..............................................
Connecting a Battery to the LED Controller 13.....................................
Aura 8 AFCS 14..................................................................................................
Aura 8 Servo Connections 14.......................................................................
Transmitter Setup 15.......................................................................................
Receiver Installation 15..................................................................................
Connecting Your Receiver to Aura 16.......................................................
Rudder and Elevator Linkage Installation 17.........................................
Rudder and Elevator Linkage Installation (continued) 18.................
Connecting Battery/Arming ESC 19..........................................................
ESC Throttle Calibration 19...........................................................................
Control Direction Test 20...............................................................................
Aura Sensor Direction Test 21......................................................................
Nose Cone, Cowling, Propeller and Spinner Installation 22..............
Battery Installation 23.....................................................................................
Center of Gravity Verification 23.................................................................
Pre-flight Checklist 24.....................................................................................
AMA Safety Code 24........................................................................................
Twin Otter 80E Aura Optional Features Configuration 25.................
Flying your Twin Otter 80E 26......................................................................
Airframe Repairs 27.........................................................................................
Replacing Servos 27........................................................................................
Aircraft Troubleshooting Guide 28.............................................................
Limited Warranty 29........................................................................................
Compliance Information for the European Union 29..........................
INTRODUCTION
The Flex Innovations Twin Otter 80E offers something incredible for everyone. At first glance, it is a
forgiving general twin engine aviation aircraft with rough field capabilities but take a deeper look
into the heart of the Twin Otter, and you’ll find its expansive capabilities. From wild 3D aerobatics, to
a gentle touch and the ability for land or water, this incredible aircraft offers a perfectly balanced
airframe for all flying styles
Combine such an incredible airframe with today’s most Advanced Flight Control System, the Aura 8
AFCS (included), and you’ll get an unmatched flying experience unavailable anywhere else. The twin
counter rotating motors cancel torque making the airplane more forgiving. When Aura is set to
Flight Mode 3, the gyro rudder gain and rate is looped to the motors providing unbelievable
additional stability in forward flight as well as in hovering flight. This differential thrust is also
coupled with the rudder control bringing aerobatic capabilities to the next level. The large flaps offer
incredible lift, allowing the Twin Otter to fly at“walking speeds”. Large control surfaces offer strong
control authority at all air speeds. Additionally, the Twin Otter 80E can also be equipped with floats
for flying offwater.
The Twin Otter 80E is the go-to, all around perfect airplane for maximum fun, unthinkable aerobatics,
and minimal hassle. From sport flying, touch and goes, to 3D aerobatics, crazy yaw maneuvering and
float flying, the Twin Otter 80E is sure to be your favorite daily flier that can do it all! Available in day
and night version with LED lights pre-installed.
For the latest updates, features, addendums and more, before assembly, please visit:
wiki.flexinnovations.com/wiki/TwinOtter_80E
wiki.flexinnovations.com/wiki/Aura
•Pre-installed and custom-tuned Aura 8
Advanced Flight Control System with
bounce-back control, preset Aura Flap
System and optional differential thrust.
•2 X 40-size, 550kV motors and 60A ESCs
for big power.
•(6) High-Precision Potenza DS34 servos.
•Light wing loading for easy handling.
•4.5-9 minute flight times depending on
battery choice and throttle
management.
•Light Weight EPO foam that is durable
and easy to repair.
•Ball-links on all control surfaces.
•Removable battery tray for easy battery
installation.
INCLUDES
•Twin Otter 80E airframe with decals applied.
•Aura 8 Advanced Flight Control System (programmed and ready to use).
•(2) Potenza 40-3D 550kv Brushless Motor.
•(2) HobbyWing 60A ESC with 7A BEC.
•(6) Potenza DS34 High Performance Digital Servo.
•(1) Potenza DS15 High Performance Digital Servo.
REQUIRES
•Minimum 8 channel computer transmitter.
•5200mAh - 6200mAh 6S 22.2V 35C+ LiPo
(FPZB62006S40 recommended).
•Serial capable receiver to match your transmitter, e.g.
Spektrum 4651T or Futaba R2001SB.
•6S LiPo capable battery charger.

3
SPECIFICATIONS
REPLACEMENT PARTS LISTING
FPM5070A
Twin Otter 80E: Super PNP Flex Army Scheme Day
FPM5080A
Twin Otter 80E: Super PNP Flex Army Scheme Night
FPM507001
Twin Otter 80E: Fuselage
FPM507002L
Twin Otter 80E: Left Wing Panel
FPM507002R
Twin Otter 80E: Right Wing Panel
FPM507003
Twin Otter 80E: Vertical Fin
FPM507004
Twin Otter 80E: Horizontal Stabilizer set
FPM507005
Twin Otter 80E: Motor Cowling Set
FPM507006
Twin Otter 80E: Nose
FPM507007
Twin Otter 80E: Main Landing Gear Wire
FPM507008
Twin Otter 80E: Main Landing Gear Mount w/Cover
FPM507009
Twin Otter 80E: Landing Gear Foam Fairing Set
FPM507010
Twin Otter 80E: Nose Landing Gear Wire
FPM507011
Twin Otter 80E: Nose Wheel Steering Assembly
FPM507012
Twin Otter 80E: Aileron and Flap Wire Harness (2)
FPM507013
Twin Otter 80E: Hardware package
FPM507014
Twin Otter 80E: Pushrod Set Assembly
FPM507015
Twin Otter 80E: Interplane Wing Struts Set
FPM507016
Twin Otter 80E: Y Harness ESC EC3/EC5 w/extensions
FPM507017
Twin Otter 80E: Left Spinner (CCW)
FPM507018
Twin Otter 80E: Right Spinner (CW)
FPM507019
Main and Nose Wheel Set
FPM507020
Twin Otter 80E: C/F Tube Set
FPM507021
Twin Otter 80E: Hatch set
FPM507022
Twin Otter 80E: Steering Tray Plywood Part
FPM507023
Twin Otter 80E: Wing Servo PCV Board Set
FPM507024
Twin Otter 80E: Float Set With Led Lights
FPM507025
Twin Otter 80E: Decal set Flex Army Scheme
FPM508001
Twin Otter 80E: Fuselage with LED Lights
FPM508002L
Twin Otter 80E: Left Wing Panel w/LED Lights
FPM508003
Twin Otter 80E: Right Wing w/ LED Lights
FPM508004
Twin Otter 80E: Vertical fin w/LED Lights
FPM508005
Twin Otter 80E: Horizontal Stabilizer set
FPM508006
Twin Otter 80E: Nose w/LED Lights
HW60AESC
HobbyWing 60A ESC with BEC
FPMPF146EL
Flex Innovation Wood Prop 14x6 Left (CW)
FPMPF146ER
Flex Innovation Wood Prop 14x6 Right (CCW)
FPZM10403D
Potenza 40 3D 550Kv Brushless Electric Motor
FPZDS34
DS34 Digital MG Mini Servo
FPZDS15
DS15 Sub-Micro Servo
FPZM10203D1
Potenza 20-3D Bolt On Prop Adapter
FPZM10403DCCW
Potenza 40-3D Bolt On Prop Adapter Left Threaded
FPZM10203D2
Potenza 20-3D Aluminum Motor Mount
FPZM10403D3
Potenza 40-3D Motor Shaft
FPZAURA8ZZOTTER
Aura 8 Advanced Flight Control System For Twin Otter
OPTIONAL ITEMS
FPM507024
Twin Otter 80E: Float Set with Led Lights
FPZ507025
Twin Otter 80E: Wing Bag Set
FPZB52006S40
Potenza 6S 5200mAh 40C LiPo Battery
FPZB62006S40
Potenza 6S 6200mAh 40C LiPo Battery
FPZB5003S25
Potenza 3S 500mAh 25C LiPo Battery (night flight)
SPMXC2000
Spektrum Smart S2100 G2 AC Charger 2X100W
SPMXBC100
Spektrum XBC100 Smart Lipo Battery Checker
SPM4651T
DSMX SRXL2 Serial Telemetry Receiver
SPMR8200
Spektrum NX8 Transmitter Only
FUTT6K
Futaba T6K Transmitter with R3006SB Rx Mode 2
FUTR2001SB
Futaba R2001SB SFHSS S-Bus
COMPLETION ITEMS
Potenza 40-3D 550 KV Brushless
Outrunner Motor (FPZM10403D )
HobbyWing 60A ESC (with BEC)
(HW60AESC )
Potenza DS34 Digital Metal Gear
Mini Servo (FPZDS34)
Aura 8 Advanced Flight Control
System For Twin Otter
(FPZAURA8ZZOTTER )
14 x 6 (x2) Wood Propeller, CW &
CCW (FPMPF146EL, FPMPF146ER)
NEEDED TO
COMPLETE
5200-6200mAh 6S 22.2V 35C+ LiPo
(FPZB52006S40, FPZB62006S40)
NEEDED TO
COMPLETE
8+ Channel Computer Transmitter
NEEDED TO
COMPLETE
RECEIVER
Serial-Capable Receiver (e.g.
Spektrum 4651T, Futaba R2001SB)
INSTALLED!
INSTALLED!
INSTALLED!
INSTALLED!
INCLUDED!
SPECIFICATIONS
Recommended battery – 6S 6200mAh 40C (FPZB62006S40) LiPo
90.0 in. (2286mm)
74.25in. (1886mm)
Day Version: 9.8lb (4450g)
Night Version: 10.0lb (4535g)
RTF with 6S 6200mAh baery installed

4
SPECIAL LANGUAGE DEFINITIONS
The following terms are used throughout the product literature to indicate various levels of potential harm when operating this product:
NOTICE:
Procedures, which if not properly followed, create a possibility of physical property damage AND a little or
no possibility of injury.
CAUTION:
Procedures, which if not properly followed, create the probability of physical property damage AND a
possibility of serious injury.
WARNING:
Procedures, which if not properly followed, create the probability of property damage, collateral damage,
and serious injury OR create a high probability of serious injury.
WARNING
AGES 14+
This product is not intended for
use by children under 14 years
without direct adult supervision.
ATTENTION
Read the ENTIRE instruction manual to become familiar with the features of the product
before operating. Failure to assemble or operate the product correctly can result in
damage to the product, personal property, and cause serious or fatal injury.
All instructions, warranties and other collateral documents are subject to change at the
sole discretion of Flex Innovations, LLC. For up-to-date product literature, please visit our
website at www.flexinnovations.com and click on the Twin Otter 80E and Aura 8 product
pages.
IMPORTANT INFORMATION REGARDING WARRANTY
Please read our Warranty and Liability Limitations section before building this product. If you as the Purchaser or user are not prepared to accept the
liability associated with the use of this Product, you are advised to return this Product immediately, in new and unused condition, to the place of
purchase.
SAFETY WARNINGS AND PRECAUTIONS
Protect yourself and others by following these basic safety guidelines.
1. This manual contains instructions for safety, operation and maintenance. It is essential to read and follow all the instructions and warnings in the
manual, prior to assembly, setup or use, in order to operate correctly and avoid damage or serious injury.
2. This model is not a toy, rather it is a sophisticated hobby product and must be operated with caution and common sense. This product requires
some basic mechanical ability. Failure to operate this product in a safe and responsible manner could result in injury or damage to the product or
other property.
3. This model must be assembled according to these instructions. Do not alter or modify the model outside of these instructions provided by Flex
Innovations, LLC, as doing so may render it unsafe and/or un-flyable. It is your responsibility to ensure the airworthiness of the model.
4. Inspect and check for the correct operation of the model and all its components before every flight.
5. If you are not an experienced pilot or have not flown a high-performance model before, it is recommended that you seek assistance from an
experienced pilot in your R/C club for your first flights. If you’re not a member of a club, the Academy of Model Aeronautics (AMA) has
information about clubs in your area whose membership includes experienced pilots.
6. Keep the propeller area clear from such items such as loose clothing, jewelry, long hair, or tools as they can become entangled. Keep your hands
and body parts away from the propeller as injury can occur.
7. Never fly in visible moisture or submerge the airplane or any of its electronic components in water. Permanent damage to electronic
components may occur, or corrosion of components may lead to intermittent failures.
LOW VOLTAGE CUTOFF
LiPo batteries have a nominal (rated) voltage of 3.7v per cell, and fully charged, reach 4.2v per cell. Batteries are designed to be discharged below the
nominal voltage, however, if they are discharged below 3.0v per cell, damage will occur and the pack will loose capacity. For best long term battery
life, set a timer and land after a time that leaves approximately 15% of the battery’s capacity remaining.
Low voltage cutoffis a feature that is built into the HobbyWing 60A ESCs that is designed to protect the connected battery from being discharged too
far and causing permanent damage to the cells. Circuitry within the ESCs will automatically detect when the input voltage from the battery pack
reaches below 3.0V per cell (average) and will remove power to the motor, but still deliver power to the servos so that a safe landing may be made. If
the motor begins to lose power rapidly during flight, the LVC has sensed that the total voltage of the pack has dropped below 3.0V per cell average,
and the airplane should be landed immediately.

5
NOTICE
Do not use thread locker when attaching plastic parts, the parts will soften and fail.
BEFORE YOU BEGIN
WARNING
Follow all instructions provided by your battery and charger manufacturer. Failure to comply can result in fire.
We recommend the use of an advanced LiPo balancing charger, such as the Spektrum Smart S2100 G2 AC 2X100W Charger for your batteries to get the
maximum performance and lifespan from them.
Our airplanes are designed around our Potenza LiPo batteries, and we recommend the Potenza 6S 6200mAh 40C LiPo in the Twin Otter 80E based on
our extensive testing and development. These batteries feature an EC5 connector, so no soldering is required for use in your Twin Otter 80E.
All are available online at www.flexinnovations.com and your local Flex Innovations retailer.
BATTERY CHARGING GUIDELINES
NOTICE
If you have the night version of the Twin Otter 80E we recommend that you dry assemble the airframe and test all the lights before
bonding anything permanently in place.
NOTICE
The assembly of the Twin Otter 80E can be accomplished in less than one hour. Prior to assembling the airplane, it is advisable to charge
your battery so that you are ready to begin setup upon completion of the assembly of your model.

6
MAIN LANDING GEAR INSTALLATION
Required Tools and Fasteners: #1 Phillips Screwdriver (4) M3x12 Phillips Head Self-Tapping Screw
1.5mm Hex Driver Blue Thread Locker
15 Minute Epoxy
1. Insert the wire landing gear into the slot in the fuselage. Insert the landing gear mount cover and secure using four M3x12mm self tapping screws.
2. Mount the wheels to the end of the landing gear with a wheel collet on each side of each wheel. Use thread locker on all the set screws.
3. Glue the foam fairings to the landing gear wire leaving a 1-2mm gap to the fuselage to allow for landing gear wire movement. We recommend using
15 minute Epoxy.
(QTY 4)

7
NOSE GEAR INSTALLATION
Required Tools and Fasteners: 1.5mm Hex Driver #1 Phillips Screwdriver
15-Minute Epoxy Craft Sticks (for mixing epoxy)
Mixing Cup Paper Towels
Thread Locker
1. Find the nose gear steering servo tray and test fit it. Once you are happy with the fit make sure surfaces all are clean and then bond the tray in place
with Epoxy adhesive. Fix it in place while the adhesive dries. Ensure that the adhesive is completely dry before proceeding.
2. Mount the wheel to the end of the nose gear strut with a wheel collet on each side of the wheel. Use thread locker on all the set screws.
3. Install the nose gear strut to the airplane with a wheel collet in the middle of each of the mounts. The steering arm goes on top of the assembly. Use
thread locker on all set screws. View picture to the right for assembly details.
4. The servo arm should be pre-installed, ensure that the push-rod is crossed over as in the picture below. Connect the servo lead to the Y-harness on
port S8 of the Aura (rudder). Once the radio is set up return to this assembly and ensure that the nose wheel is properly centered.

8
TAIL INSTALLATION
Required Tools and Fasteners: 30-Minute Epoxy 220 Grit Sandpaper
Craft Sticks (for mixing epoxy) Paper Towels
Mixing Cup Isopropyl Alcohol
Low-tack Painters tape
The tail assembly uses the short carbon fiber rod for reinforcement.
1. Dry fit the tail assembly and reinforcement rod to the fuselage. If you have the night version test the lights to ensure that they work before bonding
anything permanently.
2. Once everything fits correctly, remove the carbon fiber rod and lightly scuffit with 220 grit sandpaper to aid in adhesion. Clean all surfaces with
Isopropyl alcohol before bonding.
3. If you have the night version first connect the LEDs. Bond the tail assembly to the fuselage using 30-minute epoxy. Ensure that you get adhesive on
all the mating surfaces as well as both ends of the carbon fiber rod.
4. Insert the horizontal stab tube and the wing tube into the airplane, ensure that they are parallel before taping the tail section to the fuselage, this
step is critical or the airplane will not end up straight.
5. Tape the assembly in place with low-tack painters tape while the adhesive dries.
Note: Do not apply tape directly to any painted part as this will strip the paint offthe part, place the tape only on the white areas.

9
HORIZONTAL STABILIZER INSTALLATION
Required Tools and Fasteners: #1 Phillips Screwdriver (4) M3x8 Phillips Head Self-Tapping Screw
1. Insert and roughly center the carbon fiber horizontal stabilizer tube in the fuselage.
2. Insert both halves of the horizontal stabilizer onto the tube. Ensure that the control horn faces the bottom of the fuselage and that the elevator
jointer tabs line up properly.
3. If you have the night version, connect the LED power connectors.
4. Once both halves of the horizontal stabilizer are seated in place, secure them using four M3x8mm self tapping screws.
(QTY 4)

10
MOTOR INSTALLATION
Required Tools and Fasteners: Motor Assembly (4) M4x8 Phillips Flat Head Screw
Prop Adapter Assembly 2.5mm Hex Driver
(4) M3x10 Socket Head Cap Screw #2 Phillips Screwdriver
(4) M3x22 Phillips Button Head Screw Blue Thread Lock
1. Install the x-braces on the back of the motors using four M4x6mm flat head screws and thread locker.
2. Install the prop adapters on the front of the motors using the provided socket head hex screws and thread locker.
3. Mount the motors to the nacelles using four M3x22mm button head screws and thread locker. Note that the prop adapters are threaded for the
appropriate propeller rotation. When viewed from the rear of the airplane, the black prop adapter (normal or right handed thread) is used on the
right wing (CW) and the silver prop adapter (reverse or left handed thread) is used on the left wing (CCW).
4. Temporarily remove the ESC covers and connect the the three motor leads to the ESC leads inside the
nacelles (when you test the motors, if they spins in the wrong direction you can reverse the direction of rotation by swapping any two leads).
5. Note: Do NOT install the motor cowlings or the propellers at this point, these will be installed after radio setup and testing is complete.
(QTY 4) (QTY 4) (QTY 4)

11
MAIN WING INSTALLATION
Required Tools and Fasteners: (4) M4x18 Thumb Machine Screw #2 Phillips Screwdriver
Blue Thread Lock
1. Install and secure a wing strut on each one of the wing nacelles using a pin keeper. Do not fly the Twin Otter 80E without the wing struts, they are
a critical structural component that is required due to the motors and nacelles being on the wings.
2. Remove the hatch from the fuselage.
3. Insert and roughly center the carbon fiber wing tube in the fuselage.
4. Slide the left and right wing panels onto the tube. Ensure the servos orient towards the bottom of the fuselage.
5. Connect the single wing connector from each wing panel to the provided wing harnesses and run the servo wires through the corresponding
opening into the fuselage.
6. Run the motor power lead (with the EC3 connector) into the fuselage through the corresponding opening in the fuselage.
7. If you have the night version, run the LED power connectors into the fuselage through the corresponding openings in the fuselage.
8. Seat the wings completely in the wing saddles and secure the wings using the thumb screws through the aluminum tabs. Since the Twin Otter
80E has the motors and nacelles on the wings, and as such carry more weight on the wings, it is important that the wings are secure. For that
reason tighten the wing screws using a Phillips screwdriver before each flight.
WARNING
REMOVE THE AILERON AND FLAP SERVO ARM RETAINING SCREWS (NOT THE MOUNTING SCREWS) AND APPLY BLUE
THREAD LOCK TO THE SCREWS. RE-INSTALL THE SCREWS AND TIGHTEN FULLY. FAILURE TO DO SO MAY RESULT IN A CRASH

12
MAIN WING INSTALLATION (CONTINUED)
9. Connect the wing harness servo wires to the Aura as specified in the table on page 14 of this guide.
10. Connect each power lead to one end of the provided power lead Y-harness (2 EC3 connectors and 1 EC5 connector).
11. If you have the night version, connect the LED power connectors to the light controller. The two spare leads are used by the optional night floats.
12. Fasten the wing struts to the fuselage using the retaining pins and pin keepers.
The two spare JST connectors
are for the floats.

13
NIGHT TWIN OTTER 80E LED CONNECTIONS
If you have purchased the Night version of the Twin Otter 80E, this page will cover all LED light connections. If you did not purchase the night version,
skip ahead to the next page.
1. The first connection for the LED lights is under the carbon tube in the tail junction. This connection is made once before the tail is bonded in place.
2. There is a connection for each horizontal stabilizer half. Connect each one of these connectors the horizontal stab half while installing them.
3. There is a connection for each wing panel and a connection for each float coming out of the wing. While installing the wings route these
connectors into the fuselage through the opening provided for them. Connect each one of the two power connectors to the two unused leads in
the LED controller.
4. The nose cone has LED lights, connect these to the LED wire that is routed to the nose of the plane.
5. If using the floats with lights, connect each connector for the float set to the spare leads coming into the fuselage from the wings. You will need to
cut a hole in the bottom of the fuselage to route the LED wires coming from the floats. For details on where to cut this hole refer to the installation
manual for the Twin Otter floats. Secure the wires to the strut and fuselage using water proof tape.
LED
CONTROLLER 3S Li-Po
Black/Negative Lead
CONNECTING A BATTERY TO THE LED CONTROLLER
The LEDs on your aircraft are switchable via the transmitter, and are designed to be powered by 12 volts (3S LiPo) through the 6S JST-XH balance tab on
the LED controller. By default, the LED controller is left unplugged. If the servo lead of the LED controller is not plugged into the Aura or a
receiver, the LED controller will default in the ON position when powered, allowing the Night Version to be flown at night with a basic 8-
channel transmitter or receiver.
IN ORDER TO CONTROL THE LEDS FROM THE TRANSMITTER, YOU MUST USE A STANDARD RECEIVER THAT IS CAPABLE OF 9+ CHANNELS, AND
KEEPS THE SERVO PORTS ACTIVE WHEN USING A DIGITAL DATA STREAM (like S.Bus, SRXL2 etc.).
WARNING
You MUST use an independent 3S LiPo battery to power the LEDs in the Twin Otter 80E. Failure to do so can damage your flight batteries. We
recommend the use of the Potenza 3S 2200mAh 45C LiPo (FPZB22003S45) or the Potenza 3S 500mAh 25C LiPo (FPZB5003S25).
WARNING
Do not leave the battery plugged into the LED controller for extended periods of time. Doing so can damage the battery. Average current draw for the
lighting system is 2.2A/h
NOTICE
If you have the night version of the Twin Otter 80E we recommend that you dry assemble the airframe and test all the lights before
bonding anything permanently in place.

14
AURA 8 AFCS
The Aura 8 AFCS (Advanced Flight Control System) comes programmed and pre-installed in your Twin Otter 80E, making setup a breeze. This highly-
refined 3-axis gyro makes the Twin Otter 80E fly like it is a larger aircraft and in less wind. Thanks to the Aura’s advanced implementation, it not only
enhances the flying experience, but it never interferes with the pilot’s control.
The Aura 8 AFCS comes configured with Flight Modes (dual rates, expos and gyro settings) set by the Flex Innovations team, and offers a great starting
point for most pilots. Since these are already configured for you in the Aura, there is no need to set up dual rates, expos or flaps in your
transmitter. Simply follow the Transmitter Configuration Guide in this manual for complete details on the transmitter programming required for the
Twin Otter 80E and Aura 8 AFCS.
Visit wiki.flexinnovations.com/wiki/Aura for the latest Aura-related product information and updates.
The following shows the pre-configured Aura flight modes in the Twin Otter 80E.
Twin Otter 80E Aura Profile
Flight Mode 1: Sport (Gyro Off)
• For safety only, do not fly in this mode unless you suspect that the gyro is behaving incorrectly or erratically.
• Rates and Expos are tuned for general flying.
• Live Wing (flaps coupled to ailerons) is inactive.
• Gyro is set to off.
Flight Mode 2: Sport (Gyro On)
• For sport flying and for all taxying on the ground.
• Rates and expos are tuned for sport flying.
• Live Wing is active.
• Gyro is set to low.
Flight Mode 3: Advanced (Gyro On)
• For advanced aerobatic flight, note: do not taxi in this mode.
• Rates are highest and expos are tuned for 3D flight.
• Live Wing is active.
• Differential thrust is used (if enabled via switch).
• Gyro is set to moderately high.
In all flight modes, the flaps function with the operation of CH6 (Aux 1) on the transmitter.
NOTE - Rudder stick movement will also move the ailerons and elevator. Flap (CH6) movement will also move the elevator. This is NORMAL and is
the pre-programmed mixing.
Each of the modes has been tuned by our team to offer a solid start. Because tastes in control feel are unique, if changes in rate, expo or gains are
needed, adjustments can be made through Aura. We highly recommend that you do not change any of these in your transmitter.
The Aura 8 AFCS Profile for the Twin Otter 80E can be enhanced with optional features without the need of a computer. For further details, please see
the section of this manual titled Twin Otter 80E Aura Optional Features Configuration on page 25.
DEFAULT AURA CONNECTIONS
S1 – Left Throttle
S2 - Right Throttle
S3 – Left Aileron
S4 – Right Aileron
S5 – Elevator
S6 – Rudder
S7 – Left Flap
S8 – Right Flap
Port B – Serial Receiver Input
Mini Port A&B – Remote Receiver Inputs
Mini Port A
Mini Port B
Micro USB Port
Port B
AURA 8 SERVO CONNECTIONS

15
TRANSMITTER SETUP
The included Aura 8 is designed to work seamlessly with all popular transmitter and receiver brands, however, transmitter setup is significantly
different than when setting up a model without Aura. Follow these steps:
1. Start with a new model memory in your transmitter. Reset it to be certain it is set to defaults.
2. Adjust your transmitter settings according to the Transmitter Configuration Guide below.
3. Make ONLY the changes shown in the Transmitter Configuration Guide. No other changes are required.
Transmitter Configuration Guide
Spektrum, Futaba, JR ¹&
Graupner
FrSky
Jeti (EX-Bus)
Wing/Tail Type
1 Aileron, 1 Elevator, 1
Rudder
1 Aileron, 1 Elevator, 1
Rudder
1 Aileron, 1 Elevator, 1
Rudder
End Points
(Travel Adjust or ATV)
Ail/Ele/Rud – 125%
Ail/Ele/Rud – 100%
Aileron/Ele/Rud – 100%
Thro/CH5/CH6 – 100%
Thro/CH5/CH6 – 84%
Thro/CH5/CH6 – 80%
Reversing ²
Not Allowed
Sub-Trim
Verify at Zero, NOT ALLOWED
Trim Levers
Verify at Zero
CH5 (Gear) – Flight Mode
Assign to a 3 Position Switch
CH6 (Aux 1) – Flaps
Assign to a 3 Position Switch
(Do NOT use Transmitter Flap System)
CH7 (Aux 2) – Differential
Thrust On/Off
Assign to a 2 Position Switch
(We recommend that you use the same switch as you use for throttle cut)
CH8 (Aux 3) – Crow ³
Assign to a 2 Position Switch
First Flight Timer 4
For your first flight, set to 4:30
1 JR customers should use JR XBUS Mode A, and follow the chart above. This is the preferred JR DMSS connection to Aura.
2 If you are using a Futaba transmitter, please note that some Futaba transmitters have the throttle set to reversed by default. We recommend that
you leave the reversing set to the defaults and reverse it if needed after testing. NOTE: do all throttle testing with the props removed!
3 The default Aura program has Crow disabled, please see the section of this manual titled Twin Otter 80E Aura Optional Features Configuration
on page 25 to enable Crow.
4 This time is a safe starting point for most pilots. This aircraft can typically fly anywhere between 4.5 to 9 minutes (with 6S 6200mAh LiPo),
depending on an individual’s flying style.
FOR CUSTOMERS USING TRANSMITTERS OTHER THAN WHAT IS LISTED IN THE CHART ABOVE, PLEASE VISIT OUR WIKI PAGE
FOR INSTRUCTIONS SPECIFIC TO YOUR TRANSMITTER AND RECEIVER BRAND
HITEC – wiki.flexinnovations.com/wiki/Aura/HitecSbusUse
RECEIVER INSTALLATION
Choosing a Receiver
Aura will auto-detect modern serial receiver connections. For use in the Twin Otter 80E, only a serial receiver connection or two Spektrum
Remote Receivers can be used. Below are a few examples of serial receivers that can be used with the Aura 8. This is not a complete list of
compatible receivers, rather a short list to assist in your receiver selection.
Spektrum Remote Receivers – SPM9745 (2 Required)
Spektrum SRXL – SPMAR6610T, SPMAR8020T, SPMAR10100T
Spektrum SRXL2 – SPM4651T, SPM4650
Futaba S.Bus – Futaba R7008SB, R2001SB, R6202SBW
Hitec S.Bus – Optima SL, Maxima SL
FrSky S.Bus – RX4R, RX6R
Graupner HoTT (Sum D of 8) – GR12L, GR16L
JR XBus (Mode A & Mode B) – RG012BX, RG613BX, RG821BX
Jeti EX-Bus – REX10, R9 EX, REX6

16
Note: SRXL2 receivers like the
4651T require the use of a
different cable to connect to
Aura. The cable is included with
the receiver when it is purchased
directly from Flex Innovations.
You can also purchase the cable
itself at flexinnovations.com
(FPZA1039). Other receivers like
the AR6610T provide a standard
servo port for the SRXL2 signal.
Serial Receivers
If using a standard serial receiver, connect the provided male to male cable to
your receiver’s serial port. Connect the other end of the cable to Aura Port B
noting proper polarity.
Note: If you are using Futaba
S.Bus, be sure to use the
proper S.Bus port in your
receiver. DO NOT use the
S.Bus2 port, as it is not
supported for use with the
Aura 8. Refer to your
manufacturer's instructions
for proper S.Bus use.
Note: When using Spektrum SRXL or SRXL2 to connect to the Aura, always
connect the remote receivers to the Spektrum receiver, NOT to the Aura.
4651T
ESC
-+
-+
ESC
Binding Your Receiver
Bind your receiver to your transmitter per your receiver and transmitter
manufacturer’s instructions.
CONNECTING YOUR RECEIVER TO AURA
Spektrum Remote Receivers
If using two Spektrum Remote Receivers, connect them to
Aura Mini Port A and Mini Port B using the cable provided
with your receivers.
Binding Your DSMX Remote Receivers
1. With the transmitter and aircraft powered OFF, place a
bind plug into Aura Port S8.
2. Power on the aircraft. Your remote receivers should flash
rapidly, indicating it is in bind mode.
3. Bind your transmitter to the remote receivers per your
transmitter manufacturer’s instructions. This is typically
done by pressing and holding the bind button on your
Spektrum transmitter while powering it on.
4. Verify the receivers are bound by looking at the LED on
the Remote Receivers. This is typically indicated by a
solid orange LED on Spektrum Remote Receivers.
5. Remove the bind plug from Aura Port S8.
Aura 8 Auto-Detect
Note: Before powering up the airplane for the first time ensure that there is not trim or sub-trim on any of your main channels (aileron,
elevator or rudder) as this may lead the Aura 8 Auto-Detect feature to fail or work improperly. Once your receiver is bound, powered, and
connected to the Aura, the Aura will begin the Auto-Detect process to learn what type of receiver you are using and set itself up for that specific
system. Auto-Detect is indicated by a series of sweeping LEDs of various colors. After Auto-Detect is completed, verify that Aura is on and receiving
data from your receiver by looking at the LEDs on the Aura.
Ready-To-Fly:
Solid Orange LED: Aura On and Calibrated
Solid Green LED: Aura receiving Valid receiver data
Possible Errors:
Flashing Orange LED: Aura Moved During Power Up
No Green LED: Aura NOT receiving receiver data

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RUDDER AND ELEVATOR LINKAGE INSTALLATION
Required Tools and Fasteners: Elevator and Rudder Pushrod Assemblies #2 Phillips Screwdriver
(4) M2x10 Phillips Head Machine Screw #0 Phillips Screwdriver
(4) M2 Flat Washer Needle-Nosed Pliers (or Hemostats)
(4) M2 Lock Nut Blue Thread Lock
(2) M3x6 Phillips Head Machine Screw
1. Locate the rudder and elevator pushrod assemblies, as well as the servo arms and hardware. Note the shorter pushrod is for the elevator and the
longer one is for the rudder.
2. Power on your transmitter, and power on the airplane. Once the Aura 8 has initialized and you can verify that the servos are operating properly. Set
the flight mode to FM1before making any adjustments to servo arm positions or to pushrod lengths. This will disable the Gyro and ensure that the
control surfaces are centered and don’t have any motion if the airplane is accidentally moved.
3. With the aircraft still powered on, install the rudder and elevator servo arms perpendicular to the servo case, being sure to orient the servo arm
towards the top of the fuselage for the elevator and towards the bottom of the fuselage for the rudder (as shown below). Apply blue thread lock to
the M3x6 Phillips head machine screw, and secure the servo arm in place with a #2 Phillips screwdriver.
(QTY 4) (QTY 4) (QTY 4) (QTY 2)
WARNING
DUE TO VARIANCES IN PRODUCTION AND THE LARGE CONTROL SURFACE THROWS ON THIS AIRCRAFT, PROPER SERVO CENTERING AND
TRAVEL ADJUSTMENT IS CRITICAL TO PREVENT SERVO OVER TRAVEL AND FAILURE. IF THE SERVO ARMS ON YOUR AIRCRAFT DO NOT SIT
PERPENDICULAR TO THE SERVO CASE, YOU MUST USE THE AURA CONFIG TOOL TO ADJUST THE SUB-TRIM AND OUTPUT SCALE VALUES TO
PREVENT OVER TRAVEL OF THE SERVOS.
To download the Aura Config Tool, please visit: https://www.flexinnovations.com/aura-config-tool-install/

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RUDDER AND ELEVATOR LINKAGE INSTALLATION (CONTINUED)
4. Use a #0 Phillips screwdriver, M2x10 machine screw, M2 washer and M2 lock nut to secure the linkage to the control horn and servo arm. Use the
diagrams below for proper control horn and servo arm linkage locations. The sequence of the hardware components is as follows:
M2x10 Machine Screw
M2 Washer
Ball Link
Servo Arm or Control Horn
M2 Lock Nut
5. Repeat the process for the other control linkage.
Take this this moment to check and finalize the position of the servo arms and pushrod lengths on your ailerons, flaps and nose gear steering. Also
ensure that the motors are spinning in the correct direction, left motor is CCW and right motor is CW when viewed from the tail of the airplane (as
shown below) swap any 2 motor →ESC wires to reverse motor rotation.
Make any final control surface adjustments as necessary either mechanically or in the Aura configuration, do not use trim or sub-trim on the radio.
WARNING
Note: Do not use thread locker on the bolts holding the push rods to the servo arms or the control horns!
Using thread locker will weaken the plastic, void your warranty, and cause your airplane to crash!
Control Horns
Elevator Rudder
Servo Arms
Elevator Rudder

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ESC THROTTLE CALIBRATION
In order to map the full range of the ESCs output to your throttle stick motion you will have to preform an ESC throttle calibration. Both ESCs will
calibrate simultaneously so you only need to calibrate once. NOTE: Execute ESC throttle calibration with the propellers and spinners removed.
1. Power on your transmitter, DISABLE any throttle hold or throttle kill switches, completely lower the throttle trim and set the stick to full throttle.
2. Connect the flight pack to your Twin Otter 80E.
3. Listen for the tones coming from the ESCs through the motors, about 2 seconds after RF is engaged you should hear two tones.
4. Pull your throttle stick back to idle.
5. Listen for the ESC arming tones from the motor.
6. Unplug the flight battery to complete calibration.
The ESC throttle range has now been properly calibrated, and is stored in the ESC's memory until it is calibrated again. You can repeat this process as
many times as necessary.
CONNECTING BATTERY/ARMING ESC
Observe the following procedures to safely power up your model after
it has been bound. Ensure propellers are removed unless this
sequence is followed to power up before flight.
1. Turn on the transmitter. Lower the throttle stick AND throttle
trim to their lowest settings. Be sure to wait for your transmitter to
indicate it the radio signal is being broadcast before proceeding.
If a battery is connected to the ESCs with the throttle fully open
on the transmitter, the ESCs will enter programming mode. If
this occurs, simply disconnect the battery, lower the throttle
and reconnect the battery.
2. Ensure the aileron, elevator and rudder gimbals are centered.
3. With the airplane on a solid surface, connect the battery to the
ESCs and wait. The ESCs will make the motors emit a series of
audible tones during their initialization process.
4. The ESCs will make the motors emit a short, final tone sequence
indicating that the ESCs are now armed and that the motors will
spin in response to throttle stick movement.
WARNING
When making adjustments to linkages, transmitter settings,
or the Aura 8 flight control system, remove the propellers to
guard against accidental spool up.
WARNING
Hold aircraft securely when connecting the battery before flight.
Always ensure that the propellers are clear of any and all objects as
they may become entangled.
CAUTION
Always connect the battery when the throttle stick and throttle trim
are in the idle/cut-offposition.
CAUTION
Note: After throttle calibration is complete it is necessary to reset the failsafe on your receiver
(see your radio documentation, this may require a re-bind).