E-flite Twin Otter 1.4m Instruction Manual

Specifications

Included Equipment

• Receiver: Spektrum™ AR631+ 6-Channel AS3X+/SAFE (BNF only) Telemetry Receiver (SPM-1031)
• ESC: Avian 25-Amp Dual Smart Lite Brushless ESC, 3S-4S: IC3 (SPMXAE0225A)
• Motor: 2830-950Kv Brushless Outrunner Motor, 14-Pole (SPMXAM4500)
• Propeller: 8 x 6.5 3-Blade Propeller CW and CCW (EFLP080653B, EFLP080653BCC)
• Servos: (2) A336 9g Servos (Ailerons), (2) A336 9g Servos (Flaps), (1) A336 9g Servo (Elevator), (1) A370 9g Metal Geared Servo (Rudder/Nose Wheel)

Recommended Equipment

Optional Batteries

• SPMX27004S30: 2700mAh 4S 14.8V Smart LiPo Battery 30C; IC3
• SPMX324S50: 3200mAh 4S 14.8V Smart G2 LiPo 50C; IC3

Included Hardware

• 5 x M2.5 x 10mm Machine Screws (for Landing Gear Cover)
• 4 x M2 x 6 Countersunk Self Tapping Screws (for Upper Landing Gear Strut Fairings)
• 4 x M2 x 4 Countersunk Self Tapping Screws (for Lower Landing Gear Strut Fairings)
• 2 x M3 x 8mm Countersunk Machine Screws (for Horizontal Stabilizer)
• 2 x M4 x 14 Countersunk Machine Screws (for Wings - Front)
• 2 x M4 x 10 Countersunk Machine Screws (for Wings - Rear)
• 4 x M3 x 12mm Machine Screws (for Float Mount Brackets)
• 2 x M2.2 x 10 Self Tapping Screws (for Float Diagonal support)
• 2 x M2 x 8mm Washerhead Self Tapping Screws (for Nose Gear Strut)
• 2 x M2 x 8mm Self Tapping Screws (for Wing Strut - Top)
• 2 x M2 x 12mm Self Tapping Screws (for Wing Strut - Bottom)

Required Tools

• #1 Phillips screwdriver
• Ball link pliers (BLH100)

Safety Precautions and Warnings

General Safety:

• Read the ENTIRE instruction manual before operating. Failure to operate correctly can result in damage, personal injury, or death.
• This is a sophisticated hobby product requiring caution, common sense, and basic mechanical ability.
• Not intended for use by children without direct adult supervision.
• Do not use incompatible components or alter the product.
• Keep all chemicals, small parts, and electrical items out of reach of children.
• Avoid water exposure unless equipment is specifically designed for it; moisture damages electronics.
• Never place any part of the model in your mouth.

Operating Precautions:

• Always keep a safe distance around your model to avoid collisions or injury. Radio signals are subject to interference.
• Operate your model in open spaces away from full-size vehicles, traffic, and people.
• Follow all directions and warnings for the aircraft and any optional support equipment.
• Never operate your model with low transmitter batteries.
• Always keep the aircraft in sight and under control.
• Always use fully charged batteries.
• Always keep the transmitter powered on while the aircraft is powered.
• Always remove batteries before disassembly.
• Keep moving parts clean and parts dry.
• Allow parts to cool after use before touching.
• Always remove batteries after use.
• Ensure failsafe is properly set before flying.
• Never operate aircraft with damaged wiring.
• Never touch moving parts.

WARNING AGAINST COUNTERFEIT PRODUCTS: Always purchase replacement Spektrum receivers from Horizon Hobby, LLC or an authorized dealer to ensure authentic quality. Horizon Hobby, LLC disclaims all support and warranty for counterfeit products or those claiming compatibility with DSM or Spektrum technology.

Age Recommendation: Not for children under 14 years. This is not a toy.

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Transmitter Setup

This section details how to set up your transmitter for the Twin Otter 1.4m, covering both automatic and manual methods, and specific instructions for DX, NX, and iX series transmitters.

Auto Transmitter Setup BNF

The included receiver has a pre-loaded Smart Transmitter File (STF) for quick setup. Follow these steps:

1. Turn on the transmitter.
2. Create a new blank model file.
3. Power on the receiver.
4. Press the bind button on the receiver.
5. Put the transmitter into bind mode.
6. Once bound, a download screen will appear. Select LOAD.
7. Confirm the overwrite of current model settings.

The transmitter setup is now complete. The STF populates model parameters and renames the model.

Important Notes:

• Flight Modes: The imported file sets up Flight Modes using the Flap switch (D), allowing independent trim adjustments for each flap position (normal, takeoff, landing).
• Flight Timer: The STF does not set a flight timer. Use the transmitter's voltage monitor for alerts. If not using STF, set a 4-minute timer with the recommended battery and adjust as needed.

Supported Transmitters: All NX Radios (v4.0.11+), iX14 (app v2.0.9+), iX20 (app v2.0.9+). iX12 and DX radios do not support STF transfers.

Manual Transmitter Setup BNF

IMPORTANT: Rebind the transmitter and receiver after setup to set failsafe positions.

SAFE Select can be enabled via Forward Programming. It can be assigned to any switch on channels 5-9. Refer to the SAFE Select Switch Designation section.

For the first flight, set the flight timer to 6 minutes with a 4S 2200mAh LiPo battery.

DX Series Transmitter Setup

1. Power ON transmitter, go to System Setup, choose Yes.
2. Select , then .
3. Set Model Type to Airplane, confirm (select YES).
4. Set Model Name.
5. Go to Aircraft Type, select 1 AIL 1FLAP.
6. Select
   , enter Function List.
7. Set D/R (Dual Rate) and Expo for Aileron (Switch F: High 100%/Expo 10%, Low 70%/Expo 5%).
8. Set D/R and Expo for Elevator (Switch C: High 100%/Expo 10%, Low 70%/Expo 5%).
9. Set Throttle Cut (Switch H, Position -100%).
10. Set Flap menu values: Switch D, POS 0 (100% Flap, 0% Elevator), POS 1 (25% Flap, 16% Elevator), POS 2 (-50% Flap, 25% Elevator), SPEED 2.0s.

Note: DX6 and DX6e may require specific setup for SAFE Select switch usage.

NX Series Transmitter Setup

1. Power ON transmitter, go to System Setup, choose Yes.
2. Select , then .
3. Set Model Name.
4. Go to Aircraft Type, select 1 AIL 1FLAP.
5. Select
   , enter Function List.
6. Set D/R and Expo for Aileron (Switch F: High 100%/Expo 10%, Low 70%/Expo 5%).
7. Set D/R and Expo for Elevator (Switch C: High 100%/Expo 10%, Low 70%/Expo 5%).
8. Set Throttle Cut (Switch H, Position -100%).
9. Set Flap menu values: Switch D, POS 0 (100% Flap, 0% Elevator), POS 1 (25% Flap, 16% Elevator), POS 2 (-50% Flap, 25% Elevator), SPEED 2.0s.

iX Series Transmitter Setup

1. Power ON transmitter, open Spektrum Airware app. Select orange pen icon, then PROCEED to Turn Off RF.
2. Select three dots, then .
3. Select Model Option: DEFAULT, then Airplane. Select Create for new acro model.
4. Select the last model (Acro), rename it.
5. Press and hold back arrow to return to main screen.
6. Go to Model Setup menu, select Aircraft Type, PROCEED to Turn Off RF. Select wing: 1 Ail 1 Flap.
7. Go to Model Adjust menu.
8. Set Dual Rates and Expo for Aileron (Switch F: High 100%/Expo 10%, Low 70%/Expo 5%).
9. Set Dual Rates and Expo for Elevator (Switch C: High 100%/Expo 10%, Low 70%/Expo 5%).
10. Set Throttle Cut (Switch H, Position -100%).
11. Set Flap menu values: Switch D, POS 0 (100% Flap, 0% Elevator), POS 1 (25% Flap, 16% Elevator), POS 2 (-50% Flap, 25% Elevator), SPEED 2.0s.

Dual Rates

Attempt first flights in low rate. Use high rate elevator for landings. Do not lower rate values below 50% for AS3X+ to function properly. Adjust pushrods for less control deflection if needed. Refer to Troubleshooting Guide for oscillation at high speed.

Exponential

Adjust exponential after initial flights.

Model Assembly

Landing Gear Installation

Diagram shows the main landing gear assembly being attached to the fuselage using five M2.5 x 10mm machine screws. Landing gear fairings are attached with M2 x 6mm self-tapping screws at the upper position and M2 x 4mm self-tapping screws at the lower position. Fairings are marked 'L' (Left) and 'R' (Right) internally. The nose wheel assembly is secured to its pivot block with two M2 x 8mm washer-head screws.

Wing Installation

Install the wing joiner into the fuselage. Attach wing halves to the joiner. Secure wings with M4 x 14mm counter sunk screws at the front and M4 x 10mm counter sunk screws at the rear. Install wing struts with the rounded edge forward. Secure struts with M2 x 8mm countersunk self tapping screws at the top (wing) and M2 x 12mm countersunk self tapping screws at the bottom (fuselage).

Horizontal Stabilizer Installation

Insert the tail joiner into the fuselage. Install horizontal stabilizer halves onto the joiner. Secure with two M3 x 8mm countersunk self tapping screws. Connect the elevator ball link.

Scale Antenna Installation

Non-functional scale antennas can be stored inside the battery hatch for transport. Press antennas into position until they snap in place.

Transmitter and Receiver Binding

General Binding Tips and Failsafe BNF

• The included receiver is programmed for this aircraft. Refer to receiver manual if replaced.
• Keep away from large metal objects during binding.
• Do not point transmitter antenna directly at the receiver while binding.
• The receiver's orange LED flashes rapidly in bind mode.
• Once bound, settings are retained until re-binding.
• If receiver loses communication, failsafe activates: throttle goes low, pitch/roll stabilize aircraft in a descending turn.
• Refer to troubleshooting or contact Horizon Product Support for issues.

Binding / Enabling and Disabling SAFE Select BNF

The BNF Basic version includes SAFE Select technology for flight protection (angle limits, self-leveling). AS3X+ mode offers direct control response. SAFE Select is enabled/disabled during binding. With SAFE Select disabled, the aircraft is always in AS3X mode. With SAFE Select enabled, it can be full-time SAFE, full-time AS3X, or switchable.

IMPORTANT: Before binding, complete transmitter setup. Move flight controls and throttle trim to neutral. Move throttle to low before and during binding to set failsafe.

Binding can be done using the receiver's bind button or a bind plug. SAFE Select can also be activated via Forward Programming.

Using The Bind Button...

To Enable SAFE Select: Lower throttle, connect power, press and hold Bind Button. Orange LED flashes. Bind Tx to Rx. Release Bind Button. SAFE SELECT ENABLED: Control surfaces cycle twice with a slight pause at neutral on power-up.

To Disable SAFE Select:

Lower throttle, connect power, press and hold Bind Button. Orange LED flashes. Bind Tx to Rx. Release Bind Button. SAFE SELECT DISABLED: Control surfaces cycle once on power-up.

Using The Bind Plug...

To Enable SAFE Select: Install Bind Plug, lower throttle, connect power. Orange LED flashes. Bind Tx to Rx. Remove Bind Plug. SAFE SELECT ENABLED: Control surfaces cycle twice with a slight pause at neutral on power-up.

To Disable SAFE Select:

Install Bind Plug, lower throttle, connect power. Orange LED flashes. Bind Tx to Rx. Remove Bind Plug. SAFE SELECT DISABLED: Control surfaces cycle once on power-up.

SAFE® Select Switch Designation BNF

Once SAFE Select is enabled, you can choose full-time SAFE mode or assign a switch (channels 5-9). If bound with SAFE Select disabled, the aircraft is in AS3X mode.

CAUTION: Keep body parts clear of the propeller and secure the aircraft during throttle activation.

IMPORTANT: To assign a switch, verify SAFE Select was enabled during binding, the switch is on channels 5-9 with 100% travel, and control directions (aileron, elevator, rudder, throttle) are normal and at 100% travel (or in the 100% position if using dual rates).

Assigning a Switch

1. Power on transmitter and aircraft.
2. Hold both transmitter sticks to the inside bottom corners.
3. Toggle the desired switch 5 times quickly (full up/down = 1 toggle).
4. Control surfaces will move, indicating selection. Repeat to assign a different switch or deactivate.

SAFE Select Switch Assignment Stick Positions: Diagram shows stick positions for assigning a switch, with example showing switch on Aux3 and +/- 100% travel.

Forward Programming

Assign SAFE Select channel via Forward Programming on compatible Spektrum transmitters. Refer to: https://www.youtube.com/watch?v=o-46P066cik

Forward Programming SAFE Select Setup

1. Begin with transmitter bound to receiver.
2. Power ON transmitter.
3. Assign a switch (channels 5-9) not already in use.
4. Set switch H (throttle cut) to prevent accidental motor operation.
5. Power ON aircraft. A signal bar indicates telemetry reception.
6. Go to FUNCTION LIST (Model Setup).
7. Select Forward Programming; Select Gyro Settings, then SAFE Select.
8. Set SAFE Select channel to match the switch assigned in Step 3.
9. Set AS3X+ and SAFE On/Off as desired for each switch position.

Operation

Propeller Installation

Note correct propeller rotation for each side. Install spinner backplate, propeller, and washer. Tighten prop nut with a 10mm wrench. The left wing uses a normal rotation nut; the right wing uses a reverse thread nut. Secure the spinner with an M3 x 10mm countersunk machine screw.

Battery Installation and ESC Arming

A 4S 2200mAh 30C LiPo battery (IC3 connector) is recommended. Other 3S or 4S 2200-3200mAh LiPo batteries with IC3 or EC3 connectors are required. Ensure battery fits fuselage dimensions and weight. Always verify CG within the recommended range before flying.

NOTICE: Flying with batteries heavier than recommended (4S 3200mAh) may reduce performance (longer takeoff, reduced climb, higher stall speed, etc.).

1. Lower throttle to minimum. Power on transmitter, wait 5 seconds.
2. Remove battery hatch.
3. Apply hook and loop tape to battery and tray for security.
4. Install fully charged battery.
5. Secure with straps.
6. Connect battery to ESC (ESC is now armed).

CAUTION: Keep hands away from propeller when armed; motor will turn propeller with any throttle movement.

Keep aircraft immobile and away from wind for initialization. Motors emit two even tones when connected and armed. Slow single tones indicate LiPo cell count (e.g., three beeps for 3S). Two ascending tones indicate ESC is armed. Orange LED on receiver illuminates when initialized. Reinstall battery hatch.

ESC Error Tones

• Continuously repeating single tone: Abnormal throttle signal. Possible issues: transmitter/receiver not bound, damaged/misconnected throttle lead, throttle stick not low, reduced throttle travel, reversed throttle, raised throttle trim.
• Throttle signal not at low position: Throttle stick not at low position, reduced throttle travel, reversed throttle, or raised throttle trim.

Control Surface Centering

After assembly and transmitter setup, confirm control surfaces are centered. Model must be powered and bound in AS3X+ mode with throttle at zero. SAFE mode is active at power-up. AS3X+ activates above 25% throttle. Control surfaces may move rapidly when AS3X+ is active.

1. Verify transmitter trims and subtrims are zero.
2. Power model in AS3X+ mode, throttle at zero, enable throttle cut.
3. Check control surfaces for mechanical centering.
4. Adjust ball links to change linkage length if needed.

Center of Gravity (CG)

CG is measured from the wing's leading edge. Batteries affect CG. Verify CG is within the recommended range (42-60mm) before flight. Check CG with model upright.

CAUTION: Install battery but do not arm ESC while checking CG. Personal injury may result.

Diagram shows CG measurement: 51mm +/- 9mm behind the leading edge of the wing.

Smart™ Technology Telemetry

The Smart ESC provides real-time telemetry data (RPM, Voltage, Current, FET Temperature, BEC Temperature) to compatible Spektrum AirWare™ transmitters. During binding, the transmitter auto-configures telemetry. Adjust values as needed.

To Enter Telemetry Values:

1. Power on transmitter.
2. Set throttle cut to ON.
3. Power on aircraft.
4. In transmitter, go to Function List (Model Setup for iX series).
5. Select Telemetry menu.
6. Go to Smart Battery menu, set Startup Volts to 4.0V/cell.
7. Return to Telemetry menu.
8. Go to Smart ESC menu, set Low Voltage Alarm to 3.45V/cell, and Poles to 14.
9. Return to main screen.

Dual Rates and Control Throws

Program transmitter for desired rates and throws. Factory settings are a good starting point. Increasing throws beyond these values requires caution, as it can lead to unpredictable flight or crashes. The table shows factory settings for control horns and servo arms.

• Aileron: Low Rate: 14mm up/12mm Down; High Rate: 20mm up/18mm Down.
• Elevator: Low Rate: +/-11mm; High Rate: +/-16mm.
• Rudder: Low Rate: +/-15mm; High Rate: +/-22mm.
• Flap: Half = 10mm, Full = 20mm.

Diagrams illustrate servo arm and control horn positions for each control surface.

Control Surface Direction

Check control surface response to transmitter inputs:

• Elevator: Pull stick back: Elevators up (pitch up). Push stick forward: Elevators down (pitch down).
• Ailerons: Move stick left: Left aileron up, right aileron down (bank left). Move stick right: Right aileron up, left aileron down (bank right).
• Rudder: Move stick left: Rudder left (yaw left). Move stick right: Rudder right (yaw right).

Diagrams show transmitter stick movements and corresponding aircraft control surface responses.

AS3X+® Control Response Test

WARNING: Do not test with propeller installed; motor starting can cause injury or damage.

This test verifies AS3X+ system function. Assemble and bind aircraft first.

1. Raise throttle just above 25%, then lower to activate AS3X+.
2. WARNING: Keep body parts, hair, and clothing away from spinning motor.
3. Move the aircraft and check control surfaces. They should move as indicated in the graphic. If not, do not fly; refer to receiver manual.

AS3X+ system is active until battery is disconnected. Control surfaces may move rapidly.

Differential Thrust

The Twin Otter BNF Basic has differential thrust. Applying rudder increases speed of one motor and decreases the other to assist yaw control during ground handling, takeoff, and landing. For PNP users, a Spektrum receiver with Smart Throttle is required.

For takeoff/landing control, increase throttle trim until motors just start spinning, then reduce trim until they stop. Rudder input will then maintain directional control even at idle.

CAUTION: Throttle cut must be activated. If aircraft is picked up and yawed without trim lowered or throttle cut active, a motor may power on unexpectedly.

In Flight Trimming

During the first flight, trim for level flight at 3/4 throttle. Make small trim adjustments to straighten the flight path. After adjusting trim, do not touch control sticks for 3 seconds to allow the receiver to learn settings and optimize AS3X+ performance. Failure to do so may affect performance.

Flying Tips and Repairs

• Consult local laws before choosing a flying location.
• Flying Field: Choose wide-open spaces, preferably designated RC fields. Avoid areas with houses, trees, wires, buildings, or crowds.
• Range Check: Perform a radio system range check before flying.
• Understanding Oscillation: If oscillation occurs, decrease airspeed. If it persists, refer to the Troubleshooting Guide.
• Takeoff: Face into wind, set transmitter to low rate, gradually increase throttle. Steer with rudder. Gently pull back elevator as speed increases.
• Flying: Trim for level flight at 3/4 throttle. Do not touch sticks for 3 seconds after trimming.
• Landing: Land into the wind. Reduce throttle to a low setting, maintaining some power. Reduce throttle fully during flare and hold up elevator. Keep wings level and aircraft pointed into wind.

NOTICES:

• If a crash is imminent, reduce throttle and trim fully to minimize damage.
• After impact, ensure receiver is secure. If replaced, install new receiver in the same orientation.
• Crash damage is not covered under warranty.
• Do not leave the airplane in direct sunlight or a hot, enclosed area (e.g., car) to prevent foam damage.

Low Voltage Cutoff (LVC)

The ESC protects the LiPo battery from over-discharge using LVC. When battery voltage drops below 3V per cell, LVC pulses motor power, reserving some for flight control. Disconnect and remove LiPo battery after use. Charge LiPo to half capacity before storage. Do not let battery charge fall below 3V per cell during storage.

NOTICE: Repeated flying to LVC will damage the battery.

TIP: Use a Smart LiPo Battery Checker (SPMXBC100) to monitor battery voltage.

Repairs

EPO foam can be repaired with most adhesives (hot glue, CA, epoxy). Refer to the Replacement Parts List for ordering parts.

NOTICE: CA accelerator can damage paint. Do not handle until accelerator dries.

Post Flight Checklist

• Disconnect flight battery from ESC.
• Power OFF transmitter.
• Remove flight battery from aircraft.
• Recharge flight battery.
• Repair or replace damaged parts.
• Store flight battery separately and monitor charge.
• Note flight conditions and plan for future flights.

Receiver Installation (PNP)

The Spektrum AR631+ receiver is recommended. A 6-channel full range receiver is required if using another model. A Smart compatible receiver is needed for thrust reversing and ESC telemetry.

Installation (AR631+ shown): Mount receiver parallel to fuselage length using double-sided servo tape. Route antenna into the fuselage tube. Attach control surfaces to respective receiver ports as per the illustration.

Diagram shows AR631+ receiver with port assignments: BIND/PROG/SRXL2, 1=Throttle, 2=Ailerons, 3=Elevator, 4=Rudder, 5=N/A, 6=Flaps. Also shows active portion of antenna.

Thrust Reversing (Optional)

The Avian™ Smart ESC supports thrust reversing, useful for taxiing or shortening ground roll. Activating a switch reverses motor rotation; throttle still controls speed.

CAUTION: Never use thrust reversing in flight; it can cause loss of control and crashes. Crash damage is not covered.

IMPORTANT: Thrust reversing requires a Spektrum receiver with Smart Throttle and a 7-channel transmitter. Reversing functions are only available with Smart Throttle.

Thrust Reversing Setup

Transmitter: Assign an unused channel to a switch/button for thrust reversing. Use different channels for reversing and SAFE Select. Motor reversing is assigned to Aux 7/Channel 7 by default. Do not assign reversing and SAFE Select to the same channel.

ESC Reversing Setup

1. Bind transmitter to receiver.
2. Power ON transmitter.
3. Set switch H (throttle cut) to prevent accidental motor operation.
4. Set elevator and aileron to high rate.
5. Set Flight Mode to AS3X+ (menu won't open in SAFE mode).
6. Power ON aircraft. A signal bar indicates telemetry reception.
7. Navigate to the Avian Programming menu (Avian Prog).
8. Use elevator/aileron sticks to navigate prompts. Move stick up/down for cursor, left/right to select/return, up/down to change value.
9. Choose left or right ESC. Set Reverse for each side individually.
10. Set BRAKE TYPE: Reverse.
11. Set BRAKE FORCE: 7.
12. Set THRUST REV: Select the channel designated for reversing (default CH7, but not if used for SAFE Select).
13. Select EXIT W/ SAVE.

IMPORTANT: Reverse ESC setup must be done for both ESCs using the same channel.

Motor Service

CAUTION: Always disconnect the flight battery before performing motor service.

Disassembly

1. Remove M3 x 10mm screw from spinner cone; remove spinner.
2. Remove propeller nut (10mm wrench), washer, propeller, and spinner backplate.
3. Remove two M2 x 8mm screws from inside dummy exhausts; remove cowling.
4. Remove four M3 x 10mm screws; remove motor with X-mount.
5. Disconnect motor wires from ESC wires.
6. Remove four M3 x 6mm Phillips head machine screws; remove motor from X-mount.

Assembly

Assemble in reverse order. Correctly align motor wire colors with ESC wires. Install propeller with size numbers facing forward. Propeller may require balancing.

NOTICE: An unbalanced propeller can cause vibration, damage, and affect stabilization system performance.

Float Installation (Optional)

Float Set (EFL5261) sold separately. Remove water rudders from floats. Remove nose wheel assembly (two M2 x 8mm screws). Remove landing gear fairings (M2 x 6mm and M2 x 4mm screws). Remove landing gear cover (five M2.5 x 12mm screws). Remove landing gear straps (four M2 x 6mm screws) and reinstall cover. Remove float mount brackets (four M3 x 12mm screws). Install front and rear float wires with M3 x 12mm screws and brackets (wider wires at front). Install spreader bars between floats. Mount floats on wires, secure with brackets. Install diagonal struts from fuselage front mount to float rear mount (M3 x 9mm on float side, M2.2 x 10mm on fuselage side).

IMPORTANT: Water rudders are not used; steering on water is via differential motor thrust controlled by the aircraft rudder.

Diagrams show float installation hardware and placement.

Flying From Water

Flying from water carries higher risk. Only fly from water when comfortable flying from ground. Select areas without currents, salt water, or debris. Be aware of obstacles and avoid swimmers, boaters, and people.

• Pre-Flight: Ensure floats are secure.
• Taxiing: Use low throttle and rudder for steering. Hold up elevator to keep nose up. Steer into wind. Crab into wind for crosswind taxiing, use aileron against wind to keep upwind wing down. Do not apply down elevator during taxi or takeoff run.
• On Step: As speed increases, floats plane on water. This is a transitional phase. Do not attempt takeoff immediately. Use low/medium throttle and hold up elevator to manage speed.

Takeoff

Set flaps to takeoff position. Hold up elevator and accelerate to bring aircraft on step. Relax up elevator as it planes. Accelerate to flight speed with full throttle. Pull back slightly on elevator to rotate for liftoff.

Landing

Set flaps to landing position. Fly into wind. Reduce throttle to low, maintaining some power. Reduce throttle fully in ground effect, hold up elevator to flare. Hold up elevator through touchdown and deceleration.

WARNING: Never attempt to retrieve downed aircraft by swimming unless trained and a spotter is available.

CAUTION: Have a retrieval plan. Never retrieve a downed model alone. If water splashes into fuselage, open battery hatch immediately, remove water, and leave hatch open overnight to dry electronics.

TIP: Use a fishing pole with heavy line and a tennis ball for retrieval.

Troubleshooting Guide

AS3X+ BNF Basic Issues:

• Oscillation: Possible causes: damaged/imbalanced propeller, motor vibration, loose receiver/controls, worn parts, irregular servo movement, trim/sub-trim issues, aircraft not kept immobile for 5 seconds after connection. Solutions involve replacing/balancing parts, securing components, adjusting trim/linkages, or proper initialization.

General Troubleshooting:

• Aircraft unresponsive to throttle but responds to other controls: Check throttle at idle, throttle trim, servo travel, throttle channel reversal, motor connection to ESC.
• Extra propeller noise/vibration: Check for damaged propeller/spinner, balance propeller, tighten prop nut.
• Reduced flight time/underpowered: Check flight battery charge, propeller installation, battery condition, flight conditions (temperature), battery capacity, or use recommended battery.
• Aircraft will not Bind: Ensure transmitter is not too close, not near interference sources, bind plug is correctly installed, battery charge is sufficient, bind button/switch held long enough.
• Aircraft will not connect (after binding): Check transmitter proximity, interference sources, bind plug removal, correct model memory selection, battery charge, or transmitter binding to a different aircraft.
• Control surface does not move: Check control surface/horn/linkage damage, wire damage/loose connections, correct binding, correct airplane selection, battery charge, ESC BEC damage, or reversed transmitter settings.
• Motor power pulses then loses power: Check ESC settings (LVC), weather conditions, battery age/condition, or battery C rating.

Parts and Recommendations

Replacement Parts

A list of available replacement parts for the Twin Otter 1.4m, including wings, fuselage, stabilizers, hardware, and electronic components, is provided with part numbers.

Recommended Items

Recommended items include a 4S 2200mAh LiPo battery, a Smart S1200 G2 AC Charger, and the NX7e+ 14-Channel Transmitter.

Optional Items

Optional items include Ball Link Pliers, additional LiPo batteries, a Smart Lipo Bag, a Smart Battery Checker & Servo Driver, other chargers, and startup tool sets.

Regulatory Information

Important Federal Aviation Administration (FAA) Information

Information regarding the Recreational UAS Safety Test (TRUST), aircraft registration requirements for models over .55lbs (250g), and FAA Remote ID regulations is provided. QR codes link to further details.

AMA National Model Aircraft Safety Code

The AMA National Model Aircraft Safety Code (effective Jan 1, 2018) outlines safety guidelines for model aircraft operation, including rules on reckless flying, interference with human-carrying aircraft, operating under the influence, flying over people/vehicles, and maintaining visual contact.

Limited Warranty

Horizon Hobby, LLC warrants the Product against defects in materials and workmanship at the date of purchase. The warranty does not cover cosmetic damage, damage from misuse, modification, unauthorized service, or non-compliant use. Horizon's sole obligation is to service or replace the defective Product. Proof of purchase is required. Horizon is not liable for special, indirect, incidental, or consequential damages. The warranty is governed by Illinois law.

Contact Information

Contact information for Horizon Hobby service and support in the USA and European Union is provided, including website addresses, email, and phone numbers.

FCC Information

Contains FCC ID: BRWSPMSR6200A. This device complies with FCC Part 15 rules, subject to conditions of no harmful interference and acceptance of received interference. Changes or modifications not expressly approved could void user authority.

IC Information

Contains IC: 6157A-SPMSR6200A. Complies with Innovation, Science, and Economic Development Canada's license-exempt RSS(s).

Compliance Information for the European Union

Horizon Hobby, LLC declares compliance with EU Radio Equipment Directive, EMC Directive, and RoHS Directives for the Twin Otter 1.4m BNF (EFL32050) and PNP (EFL32075). Full EU declaration of conformity is available online. Wireless frequency range and output power are listed.

WEEE NOTICE: This appliance is labeled according to EU Directive 2012/19/EU. It should not be disposed of with household waste but deposited at an appropriate facility for recovery and recycling.