Originally Posted by
skadi
Depends on the MTOW and is regulated by the authorities.
skadi
Definitely not common in the US and it has been a complaint by the NTSB for years. After they participated in the Finnish Copterline 103 S76 (which did have a CVFDR fitted) accident investigation they formally wrote to the head of the FAA.
https://www.ntsb.gov/safety/safety-r.../A06_17_18.pdf Europe has mandated them for offshore and Part 29 aircraft for many years, and they have been invaluable.