Advisory Circulars--'glas & composite

[Richard]

I'm curious to know, given the advancements in materials and methods since then, why haven't AC 20-44 and AC 20-107A, dated from 1965 and 1984 repectively, been updated or cancelled.

WRT 20-44, I suspect the answer is because the mil specs are unchanged.

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/MainFrame?OpenFrameSet