ArduPilot V Tail Layout Fixed Wing Parameter Tuning Guide

CoreWing8/7/25About 13 minArduPilotArduPilotV 尾布局固定翼调参指南Ruddervator

I. Flight Principle Introduction

The V-tail layout is a design that integrates and simplifies traditional empennage structures. It combines the horizontal stabilizer (elevator) and vertical stabilizer (rudder) into two control surfaces mounted at an angle, forming a V shape, known as V-tail. The corresponding control surfaces are also called ruddervators. Compared to traditional fixed-wing aircraft, the main features of V-tail include:

Lighter structure and less drag: Eliminating one tail surface makes it suitable for long-endurance or high-speed aircraft;
More responsive control: The coupled pitch and yaw design provides quicker response in certain attitude control situations;
Easier wiring: The simplified tail structure is suitable for blended-wing-fuselage designs or compact layouts.

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 Beizheng BZ-251 GPS Module as an example.

5) Motor: Zhonghangdian factory 2204 KV1870 motor, suitable for 中航电 ALTUS, for reference only.

6) ESC: Zhonghangdian factory 30A ESC, suitable for 中航电 ALTUS, for reference only.

7) Servo: 9g metal servo, suitable for 中航电 ALTUS, for reference only.

8) Battery: 4S1P 4000mAh battery, suitable for 中航电 ALTUS, for reference only.

9) Propeller: 5-inch tri-blade propeller, suitable for 中航电 ALTUS, 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 common functions and interface introduction 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

III. Initial Setup

3.1 Accelerometer Calibration

Important

Note: When performing accelerometer calibration, 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 data cable.
Click Initial Setup.
Click Accelerometer Calibration.
Click Calibrate Accelerometer.

For detailed accelerometer calibration procedures, refer to:

Important

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

Important

Recalibration of the accelerometer is required when there are significant temperature and climate changes, the gyro has suffered a severe impact, or when sensors have been replaced!

Important

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

3.2 Transmitter Settings and Flight Mode Settings

Important

Navigate to the MDL/MIXES page and check if the transmitter CH1-CH4 is set to the following configuration. If not, modify the mixer.

3.2.1 Unlock Channel Settings

1. Transmitter Settings

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

2. Ground Control Station Settings

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

Important

For detailed instructions on setting up unlock and lock functions, refer to this article: https://docs.corewing.com/plane/ardupilot/settings/fc/arming-disarm-setup.html

3.2.2 Return-to-Home Channel Settings

1. Transmitter Settings

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

2. Enable Return-to-Home Switch Settings

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

3.2.3 Flight Mode Settings

1. Transmitter Settings

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

2. Ground Control Station Settings

Flight Mode Channel Settings:

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

Important

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

Flight Mode Settings:

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

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 Transmitter Calibration

Important

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

Enter Initial Setup.
Enter Transmitter Calibration.
Click Calibrate Transmitter.
Note: Check the PITCH reversal option.

Important

For detailed 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 following image for installation guidance:

Important

If you need to adjust the flight controller's 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

The installation position is shown in the image . Route the antenna outside the airframe and secure it with tape:

Set up RSSI_TYPE:

Enter configuration and debugging
Enter all parameters table
Search for RSSI_TYPE
Set the value of RSSI_TYPE to 3
Click write parameters

4.3.2 Servo Output Settings (Servo and Motor Setup) and Surface Control 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
Set outputs

Channel	Output	Description
S1	Aileron	Left aileron
S2	Aileron	Right aileron
S3	VTailLeft	Left V-tail
S4	VTailRight	Right V-tail
S5	Throttle	Throttle
S6	Throttle	Throttle

Important

Note:

The minimum and midpoint values for throttle should be consistent. When changing outputs in the ground control station, the throttle midpoint value is not automatically updated, so please check this carefully.
Output settings should be configured according to timer grouping whenever possible. Place similar devices in the same group. For timer grouping information, refer to the flight controller manual "Part5-Pin Mapping-ArduPilot Pin Mapping" section.

Surface Control Check:

a. In stabilize mode, surface control feedback check

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 response is both control surfaces deflecting down.
When the aircraft pitches down, the response is both control surfaces deflecting up.

b. In manual mode, surface control feedback check

Important

Switch flight mode to ACRO 模式

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

When moving the elevator stick up, the response is both control surfaces deflecting down.
When moving the elevator stick down, the response is both control surfaces deflecting up.

When moving the rudder stick left, the response is both control surfaces deflecting left.
When moving the rudder stick right, the response is both control surfaces deflecting right.

Check stabilize mode feedback first, then check manual mode feedback. If stabilize mode feedback is incorrect, simply check the reverse option for the incorrect control surface channel.

Important

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

Important

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

4.3.3 GPS Module Installation

The installation position is shown in the image. Secure the module to the bottom using 3M adhesive . Ensure the module is mounted securely, as this will significantly affect flight performance:

Important

When installing, ensure it is mounted level and vertically, without any tilt, otherwise the installation angle cannot be set correctly.

Important

Install away from metal components such as magnetic compartment covers, metal pushrods, etc., as these will interfere with the compass.
Install away from the receiver, servo wires, motors, and other equipment, as these will interfere with the compass.
Confirm that the installation is secure.
For detailed installation procedures for different modules, please refer to their respective manuals.

4.3.4 VTX Installation and OSD Settings

Analog VTX Installation:

Analog VTX Parameter Settings:

Important

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

HD VTX Installation:

HD VTX Parameter Settings:

Important

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

OSD Settings:

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

OSD display effect 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 Settings

Airspeed sensor installation 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

5. 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

① Click Flight Data → Click Actions → Click Unlock/Lock → Click Force Arm.

② Immediately push the throttle to the maximum.

③ Power the flight controller with the battery.

④ The ESC will play a tone → Immediately push the throttle to the minimum → The ESC tone will end.

BLHeli32/BLHeli_S ESC Calibration Sounds:

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

PWM ESC Calibration Sounds:

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

⑤ Gently push the throttle, the motor should spin immediately. Push the throttle from 0% to 20% and check if the response is linear.

⑥ 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

Choose regular or reverse propellers based on motor rotation direction
When installing propellers, ensure the side with text faces forward (toward the nose)

Important

If the motor rotation 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.
Move the aircraft around to fill the progress bar.
After the popup appears, click OK.
Click Reboot, the flight controller will restart automatically.

Important

Keep 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 during calibration to avoid USB cable interference;
If the GPS/compass module is replaced or the flight controller position is adjusted, recalibration is mandatory.

Important

Compass calibration must be accurate, otherwise it will cause ground control 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

After the flight controller is installed, a level attitude calibration must be performed to compensate for the installation angle of the gyroscope and determine the correct level flight attitude!

Place the aircraft on a flat surface for 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 for 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 Fuselage Markings:

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

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 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 rearward or reducing nose ballast.

Tail Heavy (Center of Gravity Too Far Backward):

The aircraft is prone to stall on climb.
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 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 response is both V-tail control surfaces deflecting down simultaneously.
When the aircraft pitches down, the response is both V-tail control surfaces deflecting up simultaneously.

Important

Switch flight mode to ACRO 模式

When the aileron stick is moved left, the response is the left wing control surface deflecting up and the right wing control surface deflecting down.
When the aileron stick is moved right, the response is the left wing control surface deflecting down and the right wing control surface deflecting up.
When the elevator stick is moved up, the response is both V-tail control surfaces deflecting down simultaneously.
When the elevator stick is moved down, the response is both V-tail control surfaces deflecting up simultaneously.
When the rudder stick is moved left, the response is both V-tail control surfaces deflecting left simultaneously.
When the rudder stick is moved right, the response is both V-tail control surfaces deflecting right simultaneously.

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 toss them into the air to observe their drift direction.
Determine upwind takeoff direction:
- Upwind takeoff provides greater lift and reduces takeoff speed requirements.
- Downwind takeoff may cause stalling or the nose being pushed down by wind, easily leading to a crash.

6.3 Takeoff Instructions

Based on the aircraft's actual 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 to ensure sufficient control surface deflection.
Throttle to 60-80% to ensure sufficient takeoff thrust.

2. Launch Position:

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

3. Launch Technique:

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

Important

Precautions:

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

6.3.2 Runway Takeoff

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

Important

Precautions:

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

6.4 In-flight Testing

Important

Case Study

During flight, it was not confirmed whether the aircraft's flight attitude matched the aircraft's angle of attack. During autonomous flight, the aircraft tended to pitch down. Additionally, auto-tuning was not performed, and the PID values were insufficient, resulting in insufficient control surface deflection and effectiveness during autonomous flight. 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 Onboard OSD page
Check ROLL
Check PITCH
Write to flight controller

2. Control Surface Test

After successful takeoff, switch the flight mode to FBWA 模式 to 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 and fly once downwind and once upwind, observing the OSD attitude indicator, paying 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 to 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 and fly into the wind. Check if the current cruise throttle setting maintains level flight. If the aircraft pitches up or down, adjust the cruise throttle. For nose-down, increase throttle. For nose-up, decrease throttle.
Take off again, switch to CRUISE 模式 and fly into the wind. Reconfirm if the current cruise throttle is appropriate while observing the ground speed displayed on the OSD, and record it as [Cruise Speed].

Switch to FBWA mode, maintain cruise throttle, and fly downwind. Observe the ground speed displayed on the OSD and record it as [Downwind Ground Speed].
Stay in FBWA mode, maintain cruise throttle, and 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 to 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 to test if the aircraft returns to circle near the takeoff unlock point.

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 Checks:

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

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