Chapter 8: VTOL, Transition, and Fixed-Wing Testing
8. VTOL Testing
8.1 Multicopter Feedback Logic Check
Complete the flight controller self-test and confirm that EKF3 active is displayed before arming normally and beginning the test.
8.1.1 Radio Transmitter Output Check in Q_stabilize Mode
(Apply a small amount of throttle so all three motors are rotating, then make small stick inputs to command the flight controller.)
Push the pitch stick forward: the rear motor speed increases.
Pull the pitch stick back: the front-left and front-right motor speeds increase.
Command left roll: the right motor speed increases.
Command right roll: the left motor speed increases.
8.1.2 Self-Stabilization Feedback Check in Q_stabilize Mode
(Apply a small amount of throttle so all three motors are rotating, then manually change the aircraft attitude slightly.)
When the aircraft nose is raised, the rear motor speed increases.
When the aircraft nose is lowered, the front-left and front-right motor speeds increase.
When the aircraft rolls left, the front-left motor speed increases.
When the aircraft rolls right, the front-right motor speed increases.
(If motor feedback is incorrect, verify that the motor signal wires are connected to the correct ports.)
8.2 Q_ AUTOTUNE
If handling in Qstabilize mode is unsatisfactory, use QAUTOTUNE mode to perform automatic multicopter configuration and tuning.
Consult the relevant documentation for the detailed procedure. This guide uses the Assassin T1 as an example; adjust the flight controller parameters according to the actual aircraft when using another model.
8.4 Fixed-Wing Testing (Important)
4. Output Configuration
8. First-Flight Testing and Post-Flight Tuning (Important)
9. Configuration and Tuning Complete
Precautions: Before takeoff, check the aircraft weight, center of gravity, and battery charge. After power-on, verify correct flight-mode switching and rotor feedback, and confirm that the GPS satellite lock is sufficient for safe flight.
Before testing VTOL transitions, test multicopter mode and fixed-wing mode separately. Perform transition testing only after both modes have passed their individual tests.
After VTOL mode is enabled, the power-on self-test may report AHRS: not using configured AHRS type. This message indicates that GPS stabilization is not yet complete. Wait until the OSD or message panel displays EKF3 ACTIVE before takeoff.
10. Transition Testing
After fixed-wing and multicopter operation have both been verified, flight-mode transitions can be tested. Take off and land into the wind during testing.
Procedure:
10.1 Climb to 20m in Q_stabilize mode. Adjust this altitude for the site and maintain an adequate safety margin.
10.2 Switch to FBWA mode while the aircraft is flying forward. If it cannot maintain balanced, straight flight, select FBWA or Q_stabilize mode as appropriate to recover the aircraft. After landing, adjust the relevant parameters.
10.3 After sufficient forward speed has been reached (as indicated by the OSD), switch to FBWA mode and observe the aircraft. If an abnormal condition occurs, select FBWA or Q_stabilize mode as appropriate to recover the aircraft. After landing, adjust the relevant parameters.
10.4 During fixed-wing return, allow sufficient distance, maintain a straight heading, and switch to Q_stabilize mode. If a stable landing cannot be achieved, consider performing a fixed-wing go-around before attempting another landing. After landing, adjust the relevant parameters.