FAA AD 2021-11-17 Collective axis (Control forceの増加)
FAA AD 2021-11-22 Tail Rotor 部品 Life Limit 更新 (Control ring ,sliding sleeve 等)
https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/b5c4616c95bbc63d862586f1005dcf97/$FILE/2021-11-17.pdf
https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/5814c65685bb7253862586f1005daa6a/$FILE/2021-11-22.pdf