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Troubleshooting: Erratic or Incorrect Tones

Tones are playing but at the wrong speeds, or the tone behavior is erratic and inconsistent.

Tones at Wrong Speeds

Check Calibration Quality

If the calibration R² was low (< 0.90), the AOA curve is a poor fit to your aircraft. This means tone transitions will occur at incorrect AOA values.

Fix: Re-fly the calibration wizard in calm air with a smooth, complete deceleration sweep. Aim for R² > 0.95.

Check Flap Detection

If the wrong flap position is detected, the system uses the wrong set of AOA thresholds.

Use the FLAPS console command to verify the correct flap position is showing:

FLAPS
> Flap position: 20 degrees (raw value: 158, index: 1)

If the displayed position doesn't match your actual flaps, check:

  • Potentiometer wiring and connection
  • Pot values in configuration (see Flap Position Setup)
  • Pot mechanical linkage (is it moving with the flap handle?)

Check Sensor Biases

If pressure sensor biases have drifted, the AOA reading will be offset from reality.

Fix: Recalibrate sensor biases on the ground in zero-wind conditions. See Sensor Calibration.

Erratic Tone Behavior

Fluctuating Tones in Cruise

If you hear intermittent tones during cruise (where you should hear silence):

  1. Wind gust on the ground — if testing on the ground, wind can produce airspeed and AOA readings
  2. Incorrect bias calibration — the zero-point is off, making the system think there's airflow when there isn't
  3. Moisture in lines — water in the pneumatic tubing causes pressure spikes

Rapid Tone Changes in Flight

If tones rapidly switch between regions in flight:

  1. Turbulence — in rough air, AOA fluctuates naturally. Increase AOA smoothing if this is bothersome (but be aware that more smoothing adds lag)
  2. AOA smoothing too low — try increasing the AOA smoothing value from the default of 20
  3. Pressure line issue — a loose connection or partially blocked line can cause pressure oscillations
  4. Mounting vibration — if the controller is vibrating, IMU readings will be noisy. Improve the mounting rigidity.

Check Box Orientation

If the PORTS_ORIENTATION or BOX_TOP_ORIENTATION settings don't match your physical mounting, the IMU axes are misaligned. This means pitch and roll readings are wrong, which corrupts the Derived AOA calculation.

Use the SENSORS command to verify:

  • With aircraft level: pitch ≈ 0°, roll ≈ 0°, VerticalG ≈ 1.0G
  • If these are obviously wrong, your orientation settings need to be corrected

Check for Moisture

Water in the pneumatic lines is a common cause of erratic readings, especially in humid or cold conditions:

  1. Disconnect tubing at the controller
  2. Blow through each line with dry air
  3. Reconnect and verify readings stabilize