1. Introduction
Thank you for purchasing the JJRC U9901 6CH Brushless RC Helicopter. This model features an advanced aileron-free design, optical flow positioning, barometric altitude locking, and one-key inverted flight capabilities, providing a stable and agile flying experience. Please read this manual thoroughly before operating the helicopter to ensure safe and correct usage.
2. Safety Precautions
⚠ Disclaimer: For recreation use only. Illegal modification of drones/planes is prohibited. Please also pay attention to the relevant laws and regulations on the use of drones/planes in your country/area to ensure legal use.
- Always operate the helicopter in open areas, away from people, animals, and obstacles.
- Do not fly near high-voltage lines, buildings, or crowded places.
- Keep hands, face, and loose clothing away from rotating propellers.
- Ensure the battery is fully charged before each flight.
- Do not operate in strong winds or adverse weather conditions.
- Adult supervision is recommended for users under 14 years of age.
- Turn off the helicopter and remote control when not in use.
3. Package Contents
Please check the package to ensure all items are present:
- Helicopter (x1)
- Remote Control (x1)
- Lithium Battery (x1)
- Main Rotor (x2)
- Tail Rotor (x1)
- USB Charging Cable (x1)
- Cross-head Screwdriver (x1)
- Instruction Manual (x1)
4. Specifications
| Feature | Detail |
|---|---|
| Product Name | 6CH Simulation Helicopter |
| Model Number | U9901 |
| Control Channels | 6 channels |
| Product Color | Green, Grey |
| Dimensions | 25 x 18 x 7.5 cm (Length x Width x Height) |
| Material | Metal, Plastic, Electronic components |
| Helicopter Weight | 121g |
| Motor Type | Brushless Motor |
| Body Battery | 7.4V 300mAh Lithium battery (Modular) |
| Charging Voltage | 7.4V |
| Charging Method | USB Cable |
| Charging Time | Approximately 80 minutes |
| Flight Time | Approximately 5-10 minutes (about 8 minutes per battery) |
| Remote Control Frequency | 2.4G |
| Remote Control Battery | 1.5V AA*4 (not included) |
| Remote Distance | Approximately 100m |
| State of Assembly | Ready-to-Go |
| Operator Skill Level | Beginner, Intermediate, Expert |
| Indoor/Outdoor Use | Indoor-Outdoor |
| Certification | CE |
5. Setup and First Flight
5.1. Battery Installation and Charging
- Helicopter Battery: Insert the modular 7.4V 300mAh Lithium battery into the helicopter's battery compartment. Ensure it clicks securely into place.
- Charging: Connect the USB charging cable to the helicopter's battery port and a suitable USB power source (e.g., computer USB port, USB wall adapter). The charging indicator will show the charging status. Charging takes approximately 80 minutes.
- Remote Control Batteries: Open the battery compartment on the back of the remote control. Insert 4 x 1.5V AA batteries (not included), ensuring correct polarity. Close the compartment.
5.2. Remote Control Overview
Familiarize yourself with the remote control functions:
- Power Indicator Light: Shows remote control power status.
- Emergency Stop Switch: Immediately stops all rotors. Use only in emergencies.
- 3D Switch: Activates 3D stunt mode (inverted flight).
- Throttle Up/Down & Left/Right Rotation: Left joystick controls altitude and yaw.
- Forward/Backward Movement & Left/Right Side Flight: Right joystick controls pitch and roll.
- Fine-tuning Buttons: Adjust trim for stable hovering.
- One-key Takeoff: Initiates automatic takeoff.
- One-key Landing: Initiates automatic landing.
- Optical Flow Switch: Activates optical flow positioning (enabled by default on the helicopter).
- Three-speed Settings: Cycles through low, medium, and high-speed modes.
- Power Switch: Turns the remote control ON/OFF.
5.3. Pairing the Helicopter and Remote Control
- Place the helicopter on a flat, level surface.
- Turn on the helicopter's power switch. The indicator lights will flash.
- Turn on the remote control's power switch.
- Push the left joystick (throttle) all the way up, then all the way down. The helicopter's lights will stop flashing and remain solid, indicating successful pairing.
6. Operating Instructions
6.1. Basic Flight Controls
- Takeoff: Press the 'One-key Takeoff' button or slowly push the left joystick (throttle) upwards.
- Landing: Press the 'One-key Landing' button or slowly pull the left joystick (throttle) downwards until the helicopter lands.
- Altitude Hold: The helicopter features barometric altitude locking for stable hovering.
- Directional Control: Use the right joystick for forward, backward, left, and right side flight.
- Rotation (Yaw): Use the left joystick for left and right rotation.
6.2. Advanced Flight Features
- Optical Flow Positioning: This feature helps maintain the helicopter's position, especially in indoor environments with good lighting and textured ground.
- Six-Axis Gyroscope: Provides enhanced stability and effectively corrects deviations, making it easier for beginners to control.
- Three-Speed Adjustment: Use the 'Three-speed settings' button on the remote to switch between low, medium, and high speeds, adapting to different flying environments and skill levels.
6.3. Stunt Maneuvers (One-Key Inverted Flight)
The U9901 is designed for acrobatic flight, including one-key inverted flight:
- Ensure you have sufficient altitude and clear space.
- Press the '3D Switch' button on the remote control to activate inverted flight mode.
- The helicopter will perform an inverted maneuver. Use the controls to fly upside down.
- Press the '3D Switch' again to return to normal flight.
7. Maintenance
- Cleaning: Use a soft, dry cloth to clean the helicopter after each flight. Avoid water or solvents.
- Propeller Inspection: Regularly check propellers for damage (cracks, bends). Replace damaged propellers immediately using the provided spares.
- Battery Care: Store batteries in a cool, dry place. Do not overcharge or over-discharge. If not used for a long time, charge the battery to about 50% capacity.
- Motor Care: The brushless motor is designed for durability. Keep it free from dust and debris.
- Storage: When not in use, store the helicopter and remote control in a safe place, away from direct sunlight and extreme temperatures.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Helicopter does not respond | Low battery (helicopter or remote), not paired, power switch off | Charge helicopter battery, replace remote batteries, ensure both are ON, re-pair helicopter and remote. |
| Unstable flight/Drifting | Uncalibrated gyroscope, wind interference, damaged propellers | Place on a flat surface and re-calibrate (refer to manual for specific steps), fly in calm conditions, check and replace propellers. |
| Helicopter cannot take off | Low battery, propellers installed incorrectly, motor issue | Charge battery, ensure propellers are correctly attached and spinning freely, contact support if motor is faulty. |
| Remote control signal weak | Interference, too far from helicopter, low remote battery | Fly in open areas, stay within 100m range, replace remote batteries. |
| One-key inverted flight not working | Insufficient altitude, incorrect button press | Ensure helicopter is at a safe height, press the '3D Switch' button firmly. |
9. User Tips
- Practice in Low Speed: For beginners, start with the low-speed setting to get accustomed to the controls before moving to medium or high speeds.
- Indoor vs. Outdoor: The optical flow positioning works best indoors or in calm outdoor conditions with clear ground patterns. Avoid flying over reflective surfaces or water.
- Battery Management: Consider purchasing an extra modular battery for extended flight sessions, as each battery provides about 8 minutes of flight time.
- Pre-Flight Check: Always perform a quick visual check of the propellers and ensure the battery is secure before each flight.
- Gentle Controls: RC helicopters respond best to smooth, gentle control inputs. Avoid sudden or jerky movements, especially when learning.
10. Warranty and Support
For any issues not covered in this manual, or for warranty claims, please contact the seller or manufacturer's customer support. Keep your purchase receipt as proof of purchase.
