INAV T-tail Fixed-wing Parameter Tuning Guide

CoreWingAbout 12 minINAVINAVT 尾固定翼倒 T 尾常规布局调参指南

Important

This tutorial is based on INAV 7.0.0 firmware, and operations may differ with different firmware versions!

Some content is referenced from the SpeedyBee APP interface, which is consistent with INAV ground station settings.

When tuning parameters, you can use either the SpeedyBee APP or the INAV ground station for configuration.

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 a 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 places the horizontal stabilizer below the fuselage, providing more direct airflow influence compared to a standard T-tail, resulting in the following characteristics:

Lower angle of attack dependency: Airflow acts more steadily on the stabilizer, reducing the risk of stalling during high angle of attack flight.
More direct pitch control: The horizontal stabilizer is closer to the main wing's airflow, resulting in 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, providing more stability during landing.

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 an example.

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

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

5) Motor: Zhonghang factory original 2212 KV980 motor, suitable for Feiweng, for reference only.

6) ESC: 35-45A ESC, suitable for Feiweng, for reference only.

7) Servo: 12g metal servo, suitable for Feiweng, for reference only.

8) Battery: 6S1P 10000mah battery, suitable for Feiweng, for reference only.

9) Propeller: 8-inch two-blade propeller, suitable for Feiweng, 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: A digital airspeed sensor is recommended.

Important

For ground station installation, refer to this article: https://docs.corewing.com/plane/software/insoftware/inav-version-install.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 Model Configuration

Use a USB data cable to connect the flight controller to the ground control station (GCS).
Open INAV ground control station and click Connect.

Important

If a popup appears, select Airplane with a Tail.

Important

Enter Mixer, select Airplane, select Airplane, click Load and apply.

3.2 Accelerometer Calibration

Important

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

Enter the Configuration page.
Select Auto (auto-detect) and confirm that the accelerometer has been detected.

Important

If it shows red, try reflashing the firmware to resolve the issue. If the issue persists, contact after-sales support!

Click Calibration.
Click Calibrate Accelerometer.
Follow the diagram to perform calibration.

Important

For each side calibrated, you need to click Calibrate Accelerometer once.

Important

The diagram below corresponds one-to-one with the accelerometer calibration above.

Important

After calibration is complete, click Save and Reboot.

Important

If there are significant temperature or climate changes during use, the gyro has suffered a severe impact, or sensors have been replaced, the accelerometer needs to be recalibrated!

3.3 Port Configuration

Enter the Ports page
Configure according to the table
Click Save and Reboot

3.4 GPS Configuration

Important

Enable GPS to view the NAV RTH (Return to Home) flight mode settings in the Modes page.

Enter the GPS page.
Enable the GPS for navigation and telemetry option.
Click Save and Reboot.

3.5 RC Transmitter Settings and Flight Mode Settings

3.5.1 RC Transmitter Settings

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 the Receiver page.
Configure according to the diagram.
Click Save and Reboot.

Important

For detailed information on how to set channel travel on EDGE TX, refer to this article: https://docs.corewing.com/plane/inav/settings/rc/edgetx-endpoint-setup.html

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

3.5.2 Arming Channel Setup

1. RC Transmitter Settings

Select a 2-position switch
Navigate to the MDL/MIXES page and configure its mixing as CH5

2. Ground Control Station Settings

Important

Note: Arming can only be done in flight modes that do not use GPS, such as ANGLE (self-leveling). Arming is not possible in modes that require GPS, such as NAV ALTHOLD!

Enter Modes.
Set the ARM (arming/disarming) channel to CH5, with values set between min:1700-max:2100.
Click Save.

3.5.3 Return-to-Home Channel Setup

1. RC Transmitter Settings

Select a 2-position switch.
Navigate to the MDL/MIXES page and configure its mixing as CH6 (can be set according to actual situation, for reference only).

2. Enable Return-to-Home Switch Setup

Important

By default, the return-to-home mode can only be activated when more than 5 meters away from the takeoff location. Within 5 meters, the OSD will not display the return-to-home mode!

Enter Modes.
Set the NAV RTH (return-to-home) channel to CH6, with values set between min:1700-max:2100.
Click Save.

3.5.4 Flight Mode Settings

1. RC Transmitter Settings

Select a 3-position switch to set up a 3-position flight mode switch.
Navigate to the MDL/MIXES page and configure its mixing as CH8.

2. Ground Control Station Settings

Enter Modes.
Set the ANGLE (angle mode) channel to CH8, configure according to the diagram below. To expand the value range, click Add range.
Use AUTOTUNE and ANGLE in combination, configure according to the diagram below.
Click Save.

Important

Effect: The first position is ACRO mode, the second position is ANGLE mode, and the third position is automatic tuning in ANGLE mode.

Important

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

4. Equipment Installation

4.1 Flight Controller Wiring

Power Wiring

Important

Note:

The positive power lead 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 Mounting

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

Important

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

4.3 Peripheral Installation and Setup

Peripheral Wiring

4.3.1 Receiver Installation

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

4.3.2 Mixer Setup (Servo and Motor Configuration) and Control Surface Check

Enable servo and motor outputs:

Important

After enabling servo and motor outputs, the motors and servos can operate.
In fixed-wing mode, enable motor prohibition at low throttle to prevent unnecessary damage when the motor starts spinning after arming.
For multirotor mixers, remember to set motors to stop at low throttle to enable idle.

Output Wiring:

Important

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

Parameter Configuration:

Enter the Mixer page
Configure according to the diagram
Click Save and Reboot

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

Control Surface Check:

a. Control surface feedback check in stabilization mode

Important

You must first calibrate the compass, wait for 30 seconds, then click Save and Reboot

Important

Switch the flight mode to ANGLE

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 the flight mode to ACRO

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

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

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

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

First, check if the stabilization feedback is correct. If not, add a negative sign to the Weight value of the corresponding servo mixer for the incorrect control surface feedback to reverse the surface direction.

Next, check if the manual feedback is correct. If not, you need to reverse the settings in the RC transmitter.

For example, with an EdgeTX system transmitter, navigate to MDL→INPUT page and set the Weight value to -100 to reverse the manual feedback.

4.3.3 GPS Module Installation and Configuration

The installation position is shown in the image. Secure the module to the bottom with 3M adhesive to ensure it is firmly mounted, otherwise it will significantly affect flight performance:

Important

When installing, ensure it is mounted horizontally and vertically without tilting, otherwise the installation angle cannot be set correctly.

Important

Install away from metal components such as magnetic battery covers, metal pushrods, etc., as they will interfere with the compass.
Install away from devices like receivers, servo wires, motors, etc., as they will interfere with the compass.
Ensure the installation is secure.
For detailed installation procedures of different modules, refer to their respective manuals.

Important

For detailed information on how to install and set the compass orientation, refer to this article: https://docs.corewing.com/plane/inav/settings/gps/inav-compass-setup.html

Parameter Configuration:

4.3.4 Video Transmitter Installation and OSD Configuration

Analog Video Transmitter Installation:

Analog Video Transmitter Parameter Configuration:

HD Video Transmitter Installation:

HD Video Transmitter Parameter Configuration:

OSD Configuration:

OSD configuration file: INAV_OSD file.zip, which can be downloaded and imported directly.
Enter the CLI page.
Click Load from File.
Select the OSD file.
Wait for import to complete.
Click Save Setting.

4.3.5 Airspeed Sensor Installation and Configuration

Airspeed sensor installation position reference:

Important

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

5. Pre-flight Tuning

5.1 ESC Calibration

Important

Ensure the battery is disconnected and propellers are removed!

① Enter the Output page.

② Check the risk acknowledgment option.

③ Immediately push the Master to 100%.

④ Power the flight controller with the battery.

⑤ The ESC will beep → immediately push the Master to 0% → the ESC beeping will stop.

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 number of LiPo cells → "beep" is the throttle minimum confirmation tone → calibration complete.

⑤ Gently push the throttle, the motor should start 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 enabling Dshot protocol, refer to this article: https://docs.corewing.com/plane/inav/settings/esc/esc-calib-dshot.html

5.2 Motor Direction Check and Propeller Installation

Choose normal or reverse propellers based on motor rotation direction
When installing propellers, ensure the side with text faces the nose of the aircraft

Important

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

5.3 Compass Calibration

Important

Please confirm the compass installation direction before calibration!

Enter the Configuration page.
Select Auto for automatic recognition, ensure the compass is correctly identified.

Important

If the compass icon is red, it indicates incorrect recognition. Please check the wiring or if the compass is functioning properly!

Enter the Calibrate page.
Click Calibrate Compass.
Within 30 seconds, rotate the aircraft 360° along each axis.

5.4 Failsafe Parameter Configuration

Enter the Failsafe page.
Select RTH, ensure the aircraft can autonomously return and hover above its position when signal is lost.
Click Save and Reboot.

Click Advanced Tuning.
Configure according to the diagram.
Note that the parameter in the red box needs to be set to NEVER.

Important

After configuration, remember to click Save and Reboot to save the parameters.

Click Advanced Tuning.
You can configure according to the diagram, adjust cruise throttle based on actual conditions.
Click Save and Reboot.

Important

It is recommended that during the first return flight, enter the Advanced Tuning option to manually increase throttle to avoid the default return speed being too low and prevent accidents.

6. Flight Test

6.1 Pre-flight Parameter Check

Important

For detailed information on common issues preventing arming, refer to this article: https://docs.corewing.com/plane/inav/settings/fc/fcproblem/unlock-fail-common.html

6.2 Pre-flight Inspection

6.2.1 Center of Gravity Check

1. Reference aircraft markings:

Fixed-wing aircraft will have recommended center of gravity positions 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 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 aft):

The aircraft is prone to stalling 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 ANGLE

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

Important

Switch flight mode to ACRO

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 the elevator surface deflecting down.
When the elevator stick is moved down, the response is the elevator surface deflecting up.
When the rudder stick is moved left, the response is the rudder surface deflecting left.
When the rudder stick is moved right, the response is the rudder surface deflecting right.

6.2.3 Satellite Count Check

Important

In outdoor environments, check that the satellite count is greater than 8. Takeoff is only permitted with more than 8 satellites!

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

6.2.4 Wind Direction Confirmation

Observe wind direction:
- Observe wind indicators such as smoke, wind vanes, flags.
- Use light objects (like grass leaves) tossed into the air to observe 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

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, ensuring sufficient control surface deflection.
Throttle to 60-80% to ensure adequate takeoff thrust.

2. Takeoff posture:

Hold the aircraft under the main wing; for flying wings, hold the wing to prevent hand injury.
Launch at a 30° upward angle to ensure sufficient lift.

3. Launch technique:

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

Important

Precautions:

Avoid low throttle launches. Ensure adequate takeoff power. Immediately take control of the ailerons after launch to prevent uncontrolled roll.

6.3.2 Runway Takeoff

Select ACRO 模式.
Throttle to 60-70%, maintaining moderate acceleration.
Maintain directional stability, preventing the aircraft from yawing out of control during taxi.
When sufficient speed is reached, gently pull up the pitch for a smooth takeoff.

Important

Precautions:

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

6.4 In-flight Testing

1. Control surface test:

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

Important

If the aircraft attitude is abnormal, switch to ACRO mode to land, and check the control surfaces under ANGLE 模式.

2. Level flight test

Maintain throttle at 45-55% and check if the aircraft can maintain level flight without signs of diving or climbing.

Important

If the aircraft dives or climbs, recalibrate level—use AUTOLEVEL for level calibration to align the flight controller with the wing.

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

AUTOLEVEL must be used in conjunction with primary modes and can be叠加 with ANGLE mode. For modification method, refer to AUTOTUNE settings in flight mode configuration.

3. Automatic tuning:

Switch the flight mode to AUTOTUNE 模式 to perform automatic tuning.

Important

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

4. Flight data check:

Observe OSD data to confirm that GPS, heading, altitude, ground speed, voltage, and current are normal.

Important

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

5. Return-to-home (RTH) function test:

Switch the flight mode to RTH to test if the aircraft returns to the takeoff/arming point and circles.

Important

If the flight attitude is abnormal in RTH mode, promptly switch to ACRO or ANGLE and check the RTH parameter settings!

6. Pre-landing check:

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

Technical Support QR Code

技术支持二维码.png