02-17-2017, 09:23 AM
My rule of the thump is to add ditch lights on models after 1995. That is not technically correct but "most" US engines ran after 1995 with ditch lights as far I see them on tons of photos.
A more formal answer https://www.law.cornell.edu/cfr/text/49/229.125 The are multiple dates and amendments. But December 31, 1997 looks like a final mandatory date.
A more formal answer https://www.law.cornell.edu/cfr/text/49/229.125 The are multiple dates and amendments. But December 31, 1997 looks like a final mandatory date.
Reinhard