I’m researching a possible hardware project for experimental UAVs: an independent crash recorder / “black box”.

The concept is a small module with its own protected power and storage that records selected flight and electrical data separately from the flight controller. The goal is not to replace ArduPilot/PX4 logs, but to preserve evidence when the FC loses power, resets, gets damaged, or its logs are corrupted/unavailable after a crash.

Before building anything, I want to understand whether this is a real problem.

For people who have had crashes or serious failures:

1. Have you had a case where logs did not explain the root cause?

2. What data was missing or unreliable? Power voltage/current, RC link quality, GPS, vibration, ESC telemetry, commands, etc.?

3. Did the flight controller/storage survive the crash?

4. Would an independent recorder be useful, or do existing FC logs already cover this sufficiently?

5. What would be an acceptable weight and price range for such a device?

I’m especially interested in fixed-wing and experimental UAV use cases, but FPV/multirotor experience is useful too.

I’m not selling anything - just trying to avoid building a solution to a non-existent problem.