The RC Airplane Troubleshooting Center helps you diagnose a model from the symptom you can actually see: a constant roll, nervous pitch response, takeoff yaw, gyro oscillation, short electric flight time, an overheating power system, servo buzzing, an in-flight motor cut, or intermittent radio control.
Start With the Right Category
Flight-Control and Trim Problems
- Airplane constantly rolls or needs aileron trim
- Airplane is extremely pitch sensitive
- Airplane feels sluggish in pitch
- Airplane pitches with throttle changes
- Airplane suddenly flies differently
Takeoff Problems
Stabilization Problems
Electric Power-System Problems
Radio and Servo Problems
The Five-Stage Troubleshooting Order
- Mechanical: Check hinges, horns, clevises, pushrods, servo mounts, wing and tail attachments, landing gear, firewall, and structural alignment.
- Balance: Verify center of gravity and lateral balance with the model in flight-ready condition.
- Radio: Confirm model memory, control direction, rates, travel, expo, mixes, failsafe, receiver power, antenna installation, and range.
- Stabilization: Verify receiver orientation, correction direction, gain, flight modes, mounting, and linkage tightness.
- Power: Inspect propeller, motor or engine, ESC, battery, fuel system, connectors, current draw, cooling, and vibration.
Change One Thing at a Time
Write down the symptom and the conditions in which it appears. Make one correction, repeat the same ground check or controlled flight test, and record the result. Changing CG, rates, expo, gain, thrust angle, and a propeller at the same time makes it almost impossible to know what fixed—or worsened—the problem.
Before the Return-to-Service Flight
- Use a fully charged and known-good battery.
- Repeat the complete control-direction and stabilization-direction check.
- Perform the manufacturer’s range test after radio or power-system work.
- Choose calm weather and a large familiar field.
- Use an experienced pilot or observer when possible.
- Climb to a safe altitude before evaluating trim, power changes, or stabilization.
- Keep a clear glide path and land at the first abnormal response.
When to Stop Troubleshooting Alone
Get experienced help when the model has unexplained radio holds, receiver reboots, structural damage, a shifted CG, a hot battery, repeated ESC shutdowns, incorrect gyro correction, or an intermittent control. Do not use another flight to investigate a condition that can remove control or start a fire.
RC Plane Lab provides general educational information. Follow the instructions for your specific equipment and local flying-site rules.