Are the REG's for example on a Boeing model (that meets the FAA ASSR / PART 26 requirements) accepted by EASA? If so, automatically? Do the TCH's individually have to apply for the review and approval of the REG?
There is no automatic acceptance of REGs developed to meet the FAA ASSR requirements.
As a result, the TCH has to apply to EASA for the review and approval of its REGs. However, EASA expects that significant credit for the existing content will be given. Furthermore, this subject might be covered by future revisions of the technical implementation procedures TIPs. The specific issue with REGS is that because of the elapsed time between the introduction of the requirement in the US and the introduction of the requirement in the EU, these REGs may not have a completely appropriate or achievable timeline for the aircraft surveys. Although some operators in Europe may have implemented REGs in accordance with Part-M and AMC 20-20, there was no explicit mandate for REGs to be followed in Europe until Part-26 amendment introducing ageing aircraft structures rule. In some cases, the point at which surveys would need to be done according to some REGs has already been reached and therefore those REGs need to be revised. This revision shall also make it clear to operators that the REG can be used in Europe and it's approved by EASA. Once TCHs comply with the applicable parts of Part-26, EASA will revise the TCDS to state this.