The General Aviation Joint Steering Committee (GAJSC) has identified a number of fatal general aviation accidents that were caused by attempting flight in aircraft that were undergoing maintenance and not yet returned to service. This safety enhancement suggests adopting lock out/tag out methodology to ensure pilots are aware of un-airworthy aircraft conditions.

Fact Sheet: https://www.faa.gov/news/safety_briefing/2018/media/SE_Topic_18_02.pdf