1. Introduction
The E-flite UMX Twin Otter is a Bind-N-Fly (BNF) Basic remote-controlled aircraft, designed as a scale replica of the STOL (Short Take-Off and Landing) capable cargo and passenger utility aircraft. This model is factory-assembled and includes advanced Spektrum receiver technology with AS3X and optional SAFE Select for enhanced stability and ease of flight. It features powerful brushless motors and functional scale details such as LED navigation lights and counter-rotating 3-blade propellers.
Figure 1: E-flite UMX Twin Otter BNF Basic RC Airplane.
2. Safety Information
WARNING: Read the ENTIRE instruction manual to become familiar with the features of the product before operating. Failure to operate the product correctly can result in damage to the product, personal property and cause serious injury. This is a sophisticated hobby product. It must be operated with caution and common sense and 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. This product is not intended for use by children without direct adult supervision. Do not use with incompatible components or alter this product in any way outside of the instructions provided by Horizon Hobby, LLC. The product 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.
3. Setup
The E-flite UMX Twin Otter is 100% factory-assembled and ready to fly right out of the box. However, a compatible Spektrum DSMX transmitter, a 1S 500–800mAh LiPo battery, and a suitable charger are required and not included with this BNF Basic version.
3.1 Required Items (Not Included)
Figure 2: Essential items not included with the BNF Basic model.
- Compatible Spektrum DSMX Transmitter
- 1S 500–800mAh LiPo Battery
- Compatible LiPo Charger
3.2 Battery Connection
Ensure your battery is fully charged before flight. Connect the battery to the aircraft's control unit. For 2S batteries with a 3-pin JST-PH connector, a JST-RCY to JST-PH adapter (SPMXCA327) may be required.
3.3 Binding to Transmitter
Refer to your Spektrum transmitter's manual for specific binding instructions. The aircraft is equipped with a Spektrum 2.4GHz DSMX receiver. No complex programming is required for basic flight functions.
3.4 Skill Level
Figure 3: This aircraft is recommended for pilots with some prior experience.
This aircraft is rated Skill Level 2, indicating some experience is required. It is suitable for intermediate pilots who have experience with 'Next Step' and beyond aircraft.
4. Operating
The UMX Twin Otter offers a stable and enjoyable flight experience, enhanced by AS3X and optional SAFE Select technologies. It features functional LED navigation lights for improved visibility.
4.1 AS3X and SAFE Select Technologies
The integrated Spektrum receiver includes AS3X (Artificial Stabilization - 3-axis) technology, which works behind the scenes to smooth out the effects of wind and turbulence, providing a stable and precise flight feel. For new pilots or those seeking an extra margin of safety, optional SAFE Select technology can be activated. SAFE Select offers:
- Pitch and Bank Angle Limits: Prevents excessive climb, dive angles, rolling, or pitching upside down.
- Automatic Self-Leveling: The aircraft instantly returns to and holds level flight when control sticks are released and centered.
SAFE Select is typically assigned to channel 5 (Gear) for UMX models, allowing activation/deactivation via a transmitter switch.
Figure 4: AS3X and SAFE Select technologies provide flight stability and safety features.
4.2 Flight Characteristics
The UMX Twin Otter is designed for smooth flight and can perform various maneuvers. Its powerful brushless motors and differential thrust allow for effective ground handling and turns. The aircraft is capable of STOL (Short Take-Off and Landing) operations.
Figure 5: The UMX Twin Otter can be equipped with optional floats for water operations.
4.3 LED Navigation Lights
Functional LED navigation lights are integrated into the aircraft, enhancing scale detail and improving orientation and visibility, especially in lower light conditions.
Figure 6: LED navigation lights provide enhanced visibility.
4.4 Official Product Video
Video 1: E-flite RC Airplane UMX Twin Otter BNF Basic Product Video.
4.5 Related Product Videos (Demonstrating Features)
Video 2: Carbon Cub S Plus - Demonstrates SAFE Select and flight modes.
Video 3: E-flite RC Airplane UMX Pitts S-1S BNF Basic - Showcases aerobatic flight.
Video 4: E-flite UMX A-10 Thunderbolt II 30mm EDF BNF Basic - Features of another UMX model.
5. Maintenance
Regular maintenance ensures optimal performance and longevity of your UMX Twin Otter. Always inspect the aircraft before and after each flight.
- Pre-Flight Check: Verify all control surfaces (ailerons, elevator, rudder) move freely and correctly. Check propeller integrity and ensure all components are securely attached.
- Battery Care: Always use the recommended 1S 500–800mAh LiPo batteries. Store batteries at a safe charge level and in a cool, dry place. Do not overcharge or over-discharge batteries.
- Post-Flight Inspection: Check for any damage to the airframe, propellers, or landing gear. Clean any dirt or debris from the aircraft.
- Foam Repair: Minor damage to the foam airframe can often be repaired using foam-safe adhesive.
6. Troubleshooting
This section addresses common issues you might encounter with your UMX Twin Otter.
- Aircraft not responding to controls: Ensure the transmitter is powered on, correctly bound to the aircraft, and the battery is fully charged and properly connected. Check for any loose wiring or damaged components.
- Unstable flight/Difficulty controlling: Verify that AS3X and SAFE Select are active if desired. Check for any bent control surfaces or damaged propellers. Ensure the aircraft's center of gravity (CG) is correct, typically adjusted by battery placement.
- Motor cut-off issues: If the motor cuts off prematurely, it may be due to low battery voltage. Ensure batteries are fully charged and in good condition. Some systems may not reset immediately after voltage recovery; land and replace the battery.
- Damaged components: In case of damage (e.g., cracked tail, defective engine), contact Horizon Hobby customer support for replacement parts or service.
7. Specifications
| Feature | Detail |
|---|---|
| Product Dimensions | 23.2 x 22.7 x 7.5 inches |
| Item Weight | 4.51 pounds |
| Item Model Number | EFLU30050 |
| Manufacturer Recommended Age | 14 years and up |
| Batteries | 1 Nonstandard Battery (required, not included) |
| Manufacturer | Horizon Hobby |
| First Available | December 13, 2022 |
8. Warranty and Support
For warranty information, technical support, or to order replacement parts, please contact Horizon Hobby, LLC directly. Refer to the product manual included in the box for detailed contact information and warranty terms.
