It affects airworthiness because the displays went blank when certain ILS approaches with heading 270 were selected. This is unexpected and would require the fl

It affects airworthiness because the displays went blank when certain ILS approaches with heading 270 were selected. This is unexpected and would require the flight crew to fall back on other instruments. The FAA routinely issues airworthiness directives for all sorts of safety issues. Here are a few others published in the past week or so: https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/f0ddb5e68a9223aa862584ff00566373/$FILE/2020-01-17.pdf https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf... https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/f44c3d2f513d5268862584f900515e04/$FILE/2020-01-14.pdf https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf... https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/4aea68db57652880862584f900515ce0/$FILE/2019-26-01.pdf https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf... https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/85e929ccd96d5695862584f900515b4c/$FILE/2019-25-20.pdf https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf...