U9901 2.4G RC Helicopter Six Channel Simulation Brushless Drone Optical Flow Positioning One Click Inverted Helicopter Model

U9901 2.4G 6-Channel Brushless RC Helicopter with Optical Flow Positioning
The U9901 RC Helicopter combines power precision and realism for advanced RC enthusiasts. Equipped with a brushless motor and 6-channel control system it delivers stable flight performance smooth maneuverability and responsive control. The optical flow positioning system ensures accurate hovering while the one-click inverted flight feature adds excitement to your flying experience. Perfect for both indoor and outdoor flight practice.

Overview — What is JJRC U9901

• The JJRC U9901 is a 6-channel flybarless (FBL) RC helicopter featuring a brushless motor, 6-axis gyroscope, optical-flow positioning and barometric altitude hold. Manuals++2e-通販 powered by BASE+2

• It’s designed to offer stable, precise flights, including basic hovering, directional control, and even 3D / inverted-flight stunts. Manuals++2e-通販 powered by BASE+2

• Thanks to its stabilization features and “one-key” controls (takeoff, landing, inverted flight), it aims to be friendly both to beginners and to more experienced hobbyists. Manuals++1

How to Use — Simple Manual

Setup before first flight

1. Charge the helicopter’s battery: The U9901 uses a modular 7.4 V lithium battery. Connect it via the supplied USB cable to charge (using a USB port or adapter), and wait until charging is complete. Manuals++1

2. Install remote-control batteries: The remote needs 4 × 1.5V AA batteries (not included). Open the battery compartment, insert batteries properly, then close it. Manuals++1

3. Install the helicopter battery: Insert the charged battery into the helicopter’s battery compartment and make sure it clicks in securely. Manuals++1

4. (If propellers are not pre-installed) attach main rotors and tail rotor as per markings. For inverted flight, follow instructions carefully — some propeller configurations may need adjustment. Manuals++1

Pairing remote & helicopter

• Place the helicopter on a flat, stable surface. Power on the helicopter first (its lights will flash), then power on the remote. Manuals+

• To pair: push throttle stick (left stick) all the way up, then all the way down. Solid lights indicate successful pairing. Manuals+

Basic flight controls

• Takeoff: Press the “one-key takeoff” button, or gently push the throttle up — helicopter will lift and hover. Manuals++1

• Landing: Press “one-key landing” or slowly bring throttle down until helicopter lands. Manuals+

• Altitude hold & positioning: With barometric altitude-hold plus optical flow positioning, the heli can hover steadily without constant throttle adjustment — useful indoors or in calm outdoor conditions. BestBuyBoxes+1

• Directional control: Use right stick for forward/back, left/right side motion; left stick controls yaw (rotation). Manuals+

• Speed modes: The remote has multiple speed settings (low / mid / high) to adjust flight aggressiveness depending on skill level or environment. Manuals+

Advanced / Stunt flight

• Inverted / 3D flight: Flip the “3D switch” on the remote to enable inverted flight mode. Note: correct propeller configuration is required. Practice carefully, ideally in open space. Manuals++1

• Trim & tuning: Use the fine-tuning (trim) buttons on remote if the heli drifts or is unstable during hover to improve stability. Manuals+

Maintenance & Care

• After use, wipe the heli gently with a soft, dry cloth; avoid water or chemicals. Manuals++1

• Always check propellers, housing, and motor for damage before flying; replace blades if cracked or bent. Manuals++1

• For battery care: charge fully before use; if storing for long periods, store batteries in cool, dry conditions and avoid leaving them fully discharged. Manuals++1

• Fly in open areas with minimal wind, and avoid obstacles such as trees, power-lines or crowds. Manuals++1

Demonstration / Video

A good demonstration of the U9901’s capabilities — including takeoff, hovering, inverted flight — can be seen in this video:

Comparison with Other Small RC Helicopters / Drones

Summary of Comparison

• U9901 sits as a “mid-range” RC helicopter: more advanced and capable than basic mini drones/helicopters (like H36 or Syma S107), yet simpler and more affordable than full-scale pro RC helis.

• For someone wanting to learn RC helicopter flying realistically — with full control + stabilization + optional stunt flying — U9901 is a strong choice.

• For casual fun, indoor flying, or first-time RC practice, simpler 4-ch drones/helicopters might still be easier & cheaper.

RC Helicopter Comparison: K170 vs. JJRC U9901

This comparison uses the specifications of the WLTOYS XK K170 BlackHawk UH-60L RC Helicopter.

https://youtu.be/RcUhCxw16IM

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