ArduPilot T-tail Fixed-wing Parameter Tuning Guide

CoreWing8/7/25About 13 minArduPilotArduPilotT 尾布局固定翼调参指南Conventional Tail

I. Flight Principle Introduction

The inverted T-tail (Conventional Tail) is one of the most common tail configurations for fixed-wing aircraft, consisting of a horizontal stabilizer and vertical stabilizer. Its characteristic is that the horizontal stabilizer is mounted at the rear of the fuselage, below the main wing, while the vertical stabilizer is located at the center of the fuselage, forming an inverted "T" structure.

The inverted T-tail design, with the horizontal stabilizer positioned below the fuselage, provides more direct airflow influence compared to a T-tail configuration, resulting in the following characteristics:

Lower angle of attack dependency: Airflow acts more steadily on the stabilizer, reducing the risk of stalling at high angles of attack.
More direct pitch control: The horizontal stabilizer is closer to the main wing's airflow, providing more direct elevator response and more linear control.
Stronger wind resistance: Compared to the high-mounted T-tail configuration, the low-mounted tail is less affected by crosswinds, resulting in more stable landings.

II. Equipment Preparation

Required Equipment:

1) Flight Controller: CoreWing F405 WING V2 / SpeedyBee F405 WING APP / SpeedyBee F405 WING MINI - Any of these flight controllers are suitable for this tutorial.

2) RC Transmitter: Using RadioMaster Boxer / RadioMaster TX16S as examples.

3) Receiver: Using SpeedyBee ELRS Nano 2.4G RX as an example.

4) GPS Module: Using 北征 BZ-251 GPS module as an example.

5) Motor: Langyu 2212 980KV, suitable for 肥翁, for reference only.

6) ESC: FLYCOLOR 45A, suitable for 肥翁, for reference only.

7) Servo: Using 9g metal digital servo, suitable for 肥翁, for reference only.

8) Battery: Using 6S1P 4000mah battery, suitable for 肥翁, for reference only.

9) Propeller: Using 8-inch 2-blade or 3-blade propeller, suitable for 肥翁, for reference only.

Optional Equipment:

1) Analog VTX: Using SpeedyBee TX 1600 VTX and RunCam Phoenix2 SE V2 camera as examples.

2) HD VTX: Using DJI O4 AIR UNIT VTX as an example.

3) Airspeed Sensor: Digital airspeed sensor is recommended.

Important

For ground station installation, refer to this article: https://docs.corewing.com/plane/software/apsoftware/mp-version-install.html

For introduction to common functions and pages of Mission Planner, refer to this article: https://docs.corewing.com/plane/software/apsoftware/common-functions.html

How to update flight controller firmware - using Mission Planner ground station: https://docs.corewing.com/plane/beforetuning/mp-fw-update.html

How to update flight controller firmware - using INAV ground station: https://docs.corewing.com/plane/beforetuning/inav-fw-update.html

3. Initial Setup

3.1 Accelerometer Calibration

Important

Note: When calibrating the accelerometer, be sure to remove the flight controller from the aircraft and place it on a flat surface for calibration to improve accuracy and ensure stable flight!

Connect the flight controller to the ground control station using a USB cable.
Click Initial Setup.
Click Accelerometer Calibration.
Click Calibrate Accelerometer.

For detailed accelerometer calibration procedures, refer to:

Important

After completing the operation, disconnect the ground control station and all power to the flight controller, then reconnect the ground control station.

Important

During use with significant temperature or climate changes, after the gyro has suffered a severe impact, or when sensors have been replaced, the accelerometer needs to be recalibrated!

Important

For detailed accelerometer calibration procedures, refer to: https://docs.corewing.com/plane/ardupilot/settings/fc/accel-calibration.html

3.2 RC Transmitter Setup and Flight Mode Configuration

Important

Navigate to the MDL/MIXES page and check if the RC transmitter CH1-CH4 is set as follows. If not, modify the mixing.

3.2.1 Arming Channel Setup

1. RC Transmitter Setup

Select a two-position switch
Navigate to the MDL/MIXES page and configure its mixing as CH5

2. Ground Control Station Setup

Enter Configuration/Tuning
Enter All Parameters
Search for RC5_OPTION
Set the value of RC5_OPTION to 153
Click Write Parameters

Important

For detailed information on how to set arming and disarming, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/fc/arming-disarm-setup.html

3.2.2 Return-to-Home Channel Setup

1. RC Transmitter Setup

Select a two-position switch
Navigate to the MDL/MIXES page and configure its mixing as CH6 (settings may be adjusted based on actual conditions, for reference only)

2. Enable Return-to-Home Switch Setup

Enter Configuration/Tuning
Enter All Parameters
Search for RC6_OPTION
Set the value of RC6_OPTION to 4
Click Write Parameters

3.2.3 Flight Mode Setup

1. RC Transmitter Setup

Select a three-position switch to set up a three-position flight mode switch
Navigate to the MDL/MIXES page and configure its mixing as CH8

2. Ground Control Station Setup

Flight Mode Channel Setup:

Enter Configuration/Tuning
Enter All Parameters
Search for FLTMODE_CH
Set the value of FLTMODE_CH to 8 (default is 8)
Click Write Parameters

Important

For detailed information on setting up a six-position flight mode switch, refer to: https://docs.corewing.com/plane/ardupilot/settings/rc/sixpos-switch.html

Flight Mode Setup:

Enter Initial Setup
Enter Flight Modes
Set the flight modes according to the diagram
Click Save Modes

Important

For detailed information on flight modes, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/fc/flight-modes.html

3.2.4 RC Transmitter Calibration

Important

Please bind the RC transmitter to the receiver before proceeding with the following steps.
For information on how to bind an ELRS receiver to the RC transmitter, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/rc/elrs-bind.html

Enter Initial Setup.
Enter RC Transmitter Calibration.
Click Calibrate Transmitter.
Note: Check the option to invert PITCH.

Important

For detailed RC transmitter calibration procedures, refer to: https://docs.corewing.com/plane/ardupilot/settings/fc/calibration.html

IV. Equipment Installation

4.1 Flight Controller Wiring

Power Wiring

Important

Note:

The positive power terminal must be connected to the designated pad.
ESC refers to the electronic speed controller.
When soldering, ensure there are no cold joints.

4.2 Flight Controller Installation

The flight controller should be installed at the aircraft's center of gravity. Refer to the image below for installation:

Important

If you need to adjust the flight controller's installation orientation, refer to this article for setup: https://docs.corewing.com/plane/ardupilot/settings/fc/orientation-setup.html

4.3 Peripheral Installation and Setup

Peripheral Wiring

4.3.1 Receiver Installation and Setup

Installation position is shown in the figure. Route the antenna outside the airframe and secure it with tape:

Set RSSI_TYPE:

Enter Configuration/Debugging
Enter All Parameters Table
Search RSSI_TYPE
Set the value of RSSI_TYPE to 3
Click Write Parameters

4.3.2 Servo Output Settings (Servo and Motor Setup) and Control Surface Check

Important

The flight controller has its own BEC (Battery Eliminator Circuit). If the ESC also has a BEC, you must remove the middle power wire and insulate it properly to prevent it from contacting conductors during flight, which could cause a short circuit!!!

Output Wiring:

Parameter Settings:

Enter Initial Setup
Enter Servo Output
Configure Output

Channel	Output	Description
S1	Aileron	Aileron
S2	Aileron	Aileron
S3	Elevator	Elevator
S4	Rudder	Rudder
S5	Throttle	Throttle
S6	Throttle	Throttle

Important

Note:

The minimum value and midpoint of the throttle should be consistent. When changing outputs in Mission Planner, the throttle midpoint is not automatically updated, so please check it.
Configure output settings according to timer grouping as much as possible, placing similar devices in the same group. For timer grouping, refer to the flight controller manual "Part5-Pin Mapping-ArduPilot Pin Mapping" section.

Control Surface Check:

a. Control surface feedback check in stabilization mode

Important

Switch flight mode to FBWA 模式

When the aircraft rolls left, the left wing control surface deflects down, and the right wing control surface deflects up.
When the aircraft rolls right, the left wing control surface deflects up, and the right wing control surface deflects down.

When the aircraft pitches up, the elevator control surface deflects down.
When the aircraft pitches down, the elevator control surface deflects up.

b. Control surface feedback check in manual mode

Important

Switch flight mode to ACRO 模式

When moving the aileron stick left, the feedback shows the left wing control surface deflecting up and the right wing control surface deflecting down.

When moving the aileron stick right, the feedback shows the left wing control surface deflecting down and the right wing control surface deflecting up.

When moving the elevator stick up, the feedback shows the elevator control surface deflecting down.
When moving the elevator stick down, the feedback shows the elevator control surface deflecting up.

When moving the rudder stick left, the feedback shows the rudder control surface deflecting left.
When moving the rudder stick right, the feedback shows the rudder control surface deflecting right.

Check if the stabilization feedback is correct first, then check if the manual feedback is correct. If the stabilization feedback is incorrect, simply reverse the corresponding control surface channel.

Important

In stabilization mode, if the rudder control via the transmitter is correct, then the stabilization rudder feedback must also be correct. If the stabilization feedback is incorrect, please check the rudder feedback from transmitter control.

Important

For detailed information on how to confirm if control surface feedback is correct, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/fc/dir-check.html

4.3.3 GPS Module Installation and Setup

Installation position is shown in the figure. Secure the module to the bottom with 3M adhesive ensure the module is firmly installed, otherwise it will significantly affect flight performance:

Important

During installation, ensure the module is mounted horizontally and vertically without tilting, otherwise the installation angle cannot be set correctly.

Important

Install away from metal objects such as magnetic compartment covers, metal pushrods, etc., otherwise it will interfere with the compass.
Install away from devices such as receivers, servo wires, motors, etc., otherwise it will interfere with the compass.
Ensure the installation is secure.
For detailed installation procedures for different modules, please refer to their respective manuals.

4.3.4 Video Transmitter Installation and OSD Setup

Analog Video Transmitter Installation:

Analog Video Transmitter Parameter Settings:

Important

For detailed information on analog video transmitter parameter settings, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/vtx/analog-vtx/config.html

HD Video Transmitter Installation:

HD Video Transmitter Parameter Settings:

Important

For detailed information on HD video transmitter parameter settings, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/vtx/hd-vtx/config.html

OSD Setup:

OSD configuration file: osd.param, can be downloaded and imported directly.
Enter Configuration/Debugging.
Enter All Parameters Table.
Click Load.
Select the OSD parameter file.
Click Open.
Click Write Parameters.

OSD display effect is as follows:

Important

For detailed information on how to set up OSD elements, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/fc/osd.html

4.3.5 Airspeed Sensor Installation and Setup

Airspeed sensor installation location reference:

Important

For detailed information on airspeed sensor installation, parameter settings, and calibration, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/airspeed/airspeed-setup.html

Five, Pre-flight Tuning

5.1 ESC Calibration

Important

Ensure the battery is disconnected, the receiver is bound, and propellers are removed! Switch the flight mode to Manual 模式

Click Flight Data → Click Actions → Click Arm/Disarm → Click Force Arm；

Immediately push the throttle to the maximum
Power the flight controller with the battery

ESC sounds a tone → Immediately push the throttle to the minimum → ESC tone ends

BLHeli32/BLHeli_S ESC Calibration Sounds:

Connect the battery and wait 2 seconds → "Playing a song" is the throttle maximum confirmation tone → Wait for the song to finish → Push the throttle to minimum and wait 1 second → "Playing another song, dee-dee-" is the throttle minimum confirmation tone → Calibration complete

PWM ESC Calibration Sounds:

Connect the battery and wait 2 seconds → "Beep-beep" is the throttle maximum confirmation tone → Push the throttle to minimum and wait 1 second, N beeps indicate the LiPo cell count → "Beep" is the throttle minimum confirmation tone → Calibration complete

④ Gently push the throttle, the motor should start immediately. Push the throttle from 0% to 20% and check if the response is linear.

⑤ If the result differs from the above, disconnect the battery and return to step ② to recalibrate.

Important

For detailed information on ESC calibration and enabling Dshot protocol, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/esc/esc-dshot.html

5.2 Motor Direction Check and Propeller Installation

Motors rotating outward: Facing the nose, the left motor rotates counterclockwise, the right motor rotates clockwise.

Motors rotating inward: Facing the nose, the left motor rotates clockwise, the right motor rotates counterclockwise.

Important

If the motor direction is incorrect, swap any two of the three motor wires on 任意电机 to correct the direction.

5.3 Compass Calibration

Enter Initial Setup.
Click Compass.
Check if module information is displayed. If not, check the connection cables and module.
Check Use Compass 1.
Click Start to begin compass calibration.
Shake the aircraft to fill the progress bar.
Click OK after the popup appears.
Click Reboot, the flight controller will restart automatically.

Important

Stay away from metal objects during calibration, such as cars, electric vehicles, high-voltage towers;

Calibrate outdoors with good GPS signal (at least 8 satellites);

Use wireless tuning when possible to avoid USB cable interference;

Must recalibrate if GPS/compass module is replaced or flight controller position is adjusted.

Important

Calibration must be accurate, otherwise it will cause ground station errors: EK3 active/DCM active

Important

For detailed information on compass calibration, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/gps/ap-compass-setup.html

5.4 Level Calibration

Important

A level attitude calibration must be performed after the flight controller is installed to compensate for the gyroscope's mounting angle and determine the correct level flight attitude!

Place the aircraft flat on a level surface to perform level calibration.

5.5 Failsafe Parameter Settings

Important

For detailed information on how to set failsafe parameters, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/fc/failsafe.html

6. Flight Test

6.1 Pre-flight Check Parameter Settings

Enter Configuration/Tuning.
Enter All Parameters.
Search ARMING_CHECK.
Set the required unlocked check items.

Important

For detailed information on how to set unlocked check parameters, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/fc/prearm-check-setup.html

6.2 Pre-flight Inspection

6.2.1 Center of Gravity Check

1. Reference aircraft markings:

Fixed-wing aircraft will have the recommended center of gravity marked, typically at 25-30% of the wing chord from the leading edge.

2. Finger support method:

Place the aircraft on two fingers at the recommended center of gravity point under the main wing, and gently balance the fuselage.
If the nose is too heavy or the tail is too heavy, adjust the battery or add ballast.

Nose heavy (center of gravity too far forward):

The aircraft will have difficulty climbing during flight, which may cause takeoff failure and crash.
Try moving the battery backward or reducing nose ballast.

Tail heavy (center of gravity too far back):

The aircraft is prone to stall when pitching up.
Solution: Move the battery forward or add nose ballast.

6.2.2 Pre-flight Control Surface Check

Important

Switch flight mode to FBWA 模式

When the aircraft rolls left, the left aileron moves down, and the right aileron moves up.
When the aircraft rolls right, the left aileron moves up, and the right aileron moves down.
When the aircraft pitches up, the elevator moves down.
When the aircraft pitches down, the elevator moves up.

Important

Switch flight mode to ACRO 模式

When the aileron stick is moved left, the response is the left aileron moving up and the right aileron moving down.
When the aileron stick is moved right, the response is the left aileron moving down and the right aileron moving up.
When the elevator stick is moved up, the response is the elevator moving down.
When the elevator stick is moved down, the response is the elevator moving up.
When the rudder stick is moved left, the response is the rudder moving left.
When the rudder stick is moved right, the response is the rudder moving right.

6.2.3 Satellite Count Check

Important

Outdoors, check if the satellite count is greater than 8. Only take off if it's greater than 8!

If the satellite count consistently remains below 8, move to an open area. If there's no improvement, replace the GPS module.

6.2.4 Wind Direction Confirmation

Observe wind direction:
- Observe wind indicators such as smoke, windsocks, flags.
- Use light objects (like grass leaves) and throw them into the air to observe the direction they drift.
Determine upwind takeoff direction:
- Upwind takeoff provides more lift and reduces the required takeoff speed.
- Downwind takeoff may cause stalling or the nose being pushed down by the wind, easily leading to a crash.

6.3 Hand-launch or Runway Takeoff Instructions

Depending on the aircraft configuration, choose between hand-launch or runway takeoff to ensure a successful takeoff.

6.3.1 Hand-launch

1. Mode preparation:

Select ACRO 模式, ensure the aircraft has sufficient control surface deflection.
Throttle to 60-80%, ensure sufficient takeoff thrust.

2. Takeoff posture:

Hold under the wings. For flying wings, hold the wings to prevent hand injuries.
Launch at a 30° upward angle to ensure sufficient lift.

3. Launch technique:

Use moderate force, avoid too strong or too light (insufficient for climbing).
Follow through with the motion, rather than throwing downward.

Important

Precautions:

Avoid launching with low throttle, ensure sufficient takeoff power. Immediately take control of the aileron after launching to prevent uncontrolled roll.

6.3.2 Runway Takeoff

Select ACRO 模式.
Throttle to 60%-70%, maintain moderate acceleration.
Maintain directional stability, avoid uncontrolled yaw during the taxiing phase.
When the aircraft reaches sufficient speed, gently pull up the pitch for a smooth takeoff.

Important

Precautions:

Ensure sufficient takeoff distance, avoid rapid climb in a short distance which may cause stalling.
Takeoff into the wind to increase lift, avoid crosswind effects.
Monitor flight status, prevent excessive climb or rapid banking.

6.4 In-flight Testing

Important

Case study

During flight, the aircraft's flight attitude was not confirmed to match the aircraft's angle of attack, resulting in a nose-down condition during autonomous flight. At the same time, auto-tuning was not performed, and the PID values were insufficient, causing the aircraft to be unable to generate sufficient control surface deflection for adequate control response. When switching to RTL mode, the aircraft entered autonomous flight and immediately accelerated into a dive, crashing into the ground!

First-person flight view:

Third-person flight view:

Therefore, conducting a complete in-flight test is essential.

1. OSD Settings

Enter Configuration/Tuning
Enter the Onboard OSD page
Check Roll (ROLL)
Check Pitch (PITCH)
Write to flight controller

2. Control Surface Test

After successful takeoff, switch the flight mode to FBWA 模式, and check if the aircraft automatically corrects its attitude.

Important

If the aircraft's attitude is abnormal, switch to ACRO 模式 Land and check the control surfaces under FBWA 模式.

3. Level Flight Test and Adjustment

Important

You can determine if the aircraft is pitching up or down by observing the attitude indicator on the OSD!

Switch to CRUISE 模式, fly once downwind and once upwind, observe the OSD attitude indicator, and pay attention to the pitch and roll change angles.
If the roll change angle exceeds 3°-5°, switch to FBWA 模式 to land promptly and re-perform level calibration.

If the pitch change angle exceeds 3°-5°, switch to FBWA 模式 to land, and adjust the value of PTCH_TRIM_DEG to make the aircraft maintain level flight at the proper angle of attack.

If the aircraft pitches down during level flight, increase the value of PTCH_TRIM_DEG to a positive value.
If the aircraft pitches up during level flight, decrease the value of PTCH_TRIM_DEG to a negative value.

4. Perform SERVO_AUTO_TRIM (Servo Auto-trim)

Take off, perform SERVO_AUTO_TRIM tuning, and land after tuning is complete.

Important

For information on how to perform SERVO_AUTO_TRIM (Servo Auto-trim), refer to this article: https://docs.corewing.com/plane/ardupilot/settings/fc/servo-autotrim.html

5. Auto-tuning

Take off, switch the flight mode to AUTOTUNE 模式, perform auto-tuning, and land after tuning is complete.

Important

For detailed information on how to use auto-tuning, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/fc/autotune.html

6. Throttle Optimization

Take off, switch to CRUISE 模式, fly into the wind, and check if the current cruise throttle setting allows the aircraft to maintain level flight. If the aircraft pitches up or down, adjust the cruise throttle. Increase throttle if the nose drops, decrease throttle if the nose rises.
Then take off again, switch to CRUISE 模式, fly into the wind, and confirm again if the current cruise throttle is appropriate. At the same time, observe the ground speed displayed on the OSD and record it as [Cruise Speed].

Switch to FBWA mode, maintain the throttle at cruise throttle, fly downwind, observe the ground speed displayed on the OSD, and record it as [Downwind Ground Speed].
Stay in FBWA mode, maintain the throttle at cruise throttle, fly into the wind, observe the ground speed displayed on the OSD, and record it as [Upwind Ground Speed].
[Downwind Ground Speed] ÷ 3.6 = [AIRSPEED_MAX], [Upwind Ground Speed] ÷ 3.6 = [AIRSPEED_MIN], round the results and enter them in AIRSPEED_MAX and AIRSPEED_MIN respectively.

[Cruise Speed] ÷ 3.6 = [AIRSPEED_CRUISE], ensure [AIRSPEED_CRUISE] is slightly greater than [AIRSPEED_MIN], round the result and enter it in AIRSPEED_CRUISE.

7. Flight Data Check

Observe data in Mission Planner or OSD, and confirm that GPS, heading, altitude, ground speed, voltage, current and other data are normal.

Important

If abnormal data is detected, land promptly and check the equipment!

8. Return-to-Home Function Test

Switch the flight mode to RTL 模式, and test if the aircraft returns to the takeoff unlock point and circles around it.

Important

If the flight attitude is abnormal in return-to-home mode, promptly switch to ACRO 模式 or FBWA 模式 and check the return-to-home parameter settings!

9. Pre-landing Check:

Confirm battery remaining capacity, ensure sufficient power to complete landing.
Observe wind direction, choose an upwind landing direction.

Technical Support QR Code

Technical Support QR Code.png