Keeping flight logs is a legal requirement in some jurisdictions. PX4 logs detailed aircraft performance data once the system has been armed until it is disarmed.
These flight logs can also be used to analyze performance issues.
Downloading Logs from the Flight Controller
Please ensure to use a recent version of QGroundControl, at minimum v3.2, which is available as a preview build here.
Sharing the Log Files for Review by the Developers
Please upload the log files to http://review.px4.io and share the link in the Github issue or via email.