The drone flips immediately on takeoff. This is the single most common first-flight failure mode and there are exactly four causes worth checking, in order of frequency.
Current status: this is a planning page — meaningful diagnostic detail requires a real flying drone, which is on the H2 2026 roadmap. The four causes below are the well-known ones from the ArduPilot community; we’ll add the specific diagnostic recipes once we’ve actually hit them ourselves.
Cause 1 — Wrong motor order (most common)
Multirotors number their motors by a specific convention; if you’ve wired them in the wrong order, the FC will tell motor A to spin up when it means motor B. Result: pitching one way when you commanded the other → instant flip.
Diagnostic: in ArduPilot, run motor test (MOTOR_TEST command via MAVProxy, or Setup → Motor Test in Mission Planner). Each motor should spin individually in the order you expect from the frame layout diagram.
Fix: swap the motor connectors at the ESC until the order is correct. Don’t rely on rewriting motor mapping in the FC — physical correctness first.
Cause 2 — Wrong propeller rotation
Some propellers are clockwise, some are counter-clockwise. Each motor expects a specific one (the FC will tell you which if you ask). A reversed prop tries to push the drone down with thrust applied, which feels indistinguishable from a flip to the human eye.
Diagnostic: start motor test at 10% throttle, look at airflow direction relative to the prop label.
Fix: swap props for correct rotation, or reverse motor direction via BLHeli config.
Cause 3 — Center of gravity off
If the battery shifted forward by 5 mm during preflight, the drone will pitch nose-down at the slightest input. Severe CG offsets produce immediate flips.
Diagnostic: balance the powered-off drone on a finger or pencil at the center. If it tips heavily one way, the CG is off.
Fix: reposition the battery / move ballast to match the design CG (typically at the geometric center of the frame, plus or minus a few mm).
Cause 4 — PID tuning wrong
If you’ve adjusted PID gains aggressively and overshot stability, the drone will oscillate, and a hard oscillation looks like a flip.
Diagnostic: check ATC_RAT_PIT_P and ATC_RAT_RLL_P in ArduPilot. Defaults for a 5-inch indoor quad are around 0.1 - 0.135. Values significantly above that produce visible oscillations.
Fix: restore defaults, then tune from there with the AutoTune mode.
Where to go next
- Takeoff node evolution — the software-side analog of taking off correctly
- Pre-flight checklist — preventing this in the first place
- Troubleshooting hub — sibling diagnostic guides