Are the repairs / alterations / changes, that are validated under the FAA PART 26 rule, automatically acceptable under the new EASA AASR rule?
The damage tolerance (DT) data that has been approved by the FAA can be used to demonstrate compliance with Part-26 where the requirements are equivalent. The means to accept that data and approve it or recognize it as approved data for use by EU operators is subject to specific considerations, therefore it should be discussed with EASA as part of the compliance plan that STC holders have to submit to EASA in accordance with point 26.331 of Part-26. Note that according to point 26.333, DT data already approved by EASA for STCs issued on or after 1st September 2003 does not need to be submitted for approval if it is confirmed to be complete by the STCH in the compliance plan.
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.
Point 26.331: Shall a compliance plan be submitted to EASA by STC holders that do not hold structures in their DOA Scope of Work; and only owns STCs that are cabin related and do not introduce fatigue-critical modified structure (FCMS)?
If the STC does not affect the Fatigue Critical Baseline Structure (FCBS) and does not introduce the Fatigue Critical Modified Structure (FCMS), the STCH would not be affected by ageing aircraft requirements introduced in Part-26. However, it should be considered that sometimes interior changes may affect the FCBS, for instance introduction of a galley, or of a large portable water tank, that does not use existing TCH or otherwise approved attachment points for which the allowable loads are known.
As STC Holders how can we obtain the list of FCBS?
The TCH’s are bound to make the FCBS list available. That may come with some arrangement being required, but typically we see the list of FCBS included in the structural repair manuals (SRMs). Unless a database with the necessary information is already available, or can be established conservatively by the STC holder, they should approach the TCH directly to obtain these info. The Agency will approve TCH FCBS lists, however the lists that have been produced to show compliance with CFR 14 Part 26 may already be available. In this case unless the TCH wishes to change the content due to specific reasons, EASA is not seeking to introduce changes to those lists and the EASA approval is expected to be straightforward.
When not sure if FCBS is affected by an STC, is there any Compliance Plan required?
There is a time limit for the submittal of the Compliance Plan to EASA, so if an STC holder can’t establish easily that an STC has no impact on Fatigue Critical Structure then a conservative approach should be implemented. This means that the subject STC will be provisionally included in the compliance plan and additional information on how to deal with it will be provided. If an STC holder is sure that there are no STCs affecting the FCBS, then there's no need to submit a compliance plan.
An EASA approved STC is applied to aircraft which are nowadays operated in the US under FAA regulations. Does the F&DT still need to be performed? Or could we wait until an actual operator contacts us?
The need to act depends on the date of issuance of the STC approval, see points 26.333 and 26.334. For STCs issued on or after September 1, 2003 the STC holder must perform and submit DTE unless it has already been completed and approved. For STCs issued prior to 1st Sept 2003, the STC holder can wait for an operator request. STC holders do not need to respond to operator requests under this regulation if the operator is not subject to point 26.370(a)(ii), however, the STC holder may be subject to foreign authority requirements as a holder of an STC approved by a non-EU state.
Will Appendix 1 Table A.1 be updated to list all aircraft who successfully apply for exceptions per 26.300 via their compliance plans?
No. EASA recommends that TCHs make such information available. EASA will consider if other means of increasing awareness are necessary.
There are many structural repairs manual (SRM) repairs to fatigue critical structure (FCS) however the SRM does not define the classification of the repair per 21A91/21.435. How does an operator know the repair classification if it has not been specified per SRM?
If the reinforcing repair and associated ICA is implemented in accordance with the SRM approved data at the time of the repair the CAMO should check whether that data is still valid according to the latest SRM and TCH REGs and if it is not clear as to what action to take then the CAMO should contact the TCH to establish whether new or revised DTI are required. All reinforcing repairs to FCS performed in accordance with the SRM should be reviewed for completeness and applicability of DTI as necessary in accordance with the TCH REGs, SRM or other applicable data.If the reinforcing repair and associated ICA is implemented in accordance with the SRM approved data at the time of the repair the CAMO should check whether that data is still valid according to the latest SRM and TCH REGs and if it is not clear as to what action to take then the CAMO should contact the TCH to establish whether new or revised DTI are required. All reinforcing repairs to FCS performed in accordance with the SRM should be reviewed for completeness and applicability of DTI as necessary in accordance with the TCH REGs, SRM or other applicable data.
26.370(a) (ii): where an operator's fleet consists of a/c certificated after 2009 and therefore has no REG - there will be no "REG" survey compliance threshold for repairs. When does one therefore plan to review the DTI?
The TCH repairs and associated DTI for new aircraft types first certificated after January 11, 2008 may be assumed to be compliant with the applicable damage tolerant certification basis and therefore Part-26. A records review should normally be sufficient on such a new aircraft to identify if there are third party reinforcing repairs to FCS and establish if those repairs have been approved appropriately and provided with DTI where necessary. Ultimately, for such aircraft, and not withstanding Part-26, the need to ensure compliance with the applicable certification basis is a primary consideration and it is therefore recommended that the records review should be conducted and any missing DTI incorporated in the AMP as soon as possible. The allowances for evaluating repairs to older aircraft provided by the guidance of AMC 20-20A for development of the TCH REGs are not envisaged to be necessary or utilized for these newer aircraft.
Will rework repairs (blend out, trim-outs, etc.) be on a list of repairs that require DTE?
All repairs should be DT from now on, e.g. in the SRM, all the inspection data will be fully DT compliant. However, you won't be expected to evaluate existing blend outs, trim-outs, etc.. The plan for addressing the existing repairs only needs to address what we call reinforcing repairs, where a strap or reinforcing doubler or similar part is added. From now on you will always get DT data from the DAHs that is DT compliant.
Is it our correct interpretation of 26.370 g(5) that a physical survey for repairs for aircraft certified as per CS 25.571 (Damage Tolerance) is not a must as long as repair records for the aircraft are considered complete by the CAMO and the requirements per TC REG are complied with for any known repair?
Yes, that is correct, it's not a must as long as repair records are considered complete by the CAMO. It is recommended in some cases, particularly for older aircraft, because the records are not always as good as expected. Confidence in records will increase with the newer aircraft in general terms, with less repairs and with adherence to the stronger evolving requirements for records and data management.
Who needs to evaluate a change / repair in case the original design organization for the change / repair no longer exists?
In this case the operator needs to find an appropriately qualified third party to perform the DTE and develop DTI. An approved design organization could take that evaluation on.
Typically a DTI has a threshold and interval, how should the operator establish that start time (to calculate the 1st due inspection) if an unrecorded Mod/repair was found during the survey, and not knowing the cycles/landing at Incorp of the Mod/repair? Is that covered by the Reg?
There is guidance on this in AMC 20-20A, for a repair that may have exceeded the threshold. One can make the conservative assumption that repairs were implemented soon after the aeroplane went into service, however, the repair may have exceeded the formal threshold, so the AMC provides generically agreed grace periods. These periods, typically 12 – 24 months will be specified by the TCH in the REGs and were agreed some time ago and should be followed by operators unless a specific concern arises. AMC 20-20A provides also guidance regarding the way to handle inspections for rotable parts.
Regulation (EU) 2021/699 introduced point 21.A.101(h) that refers, among others, to point 26.320 of Regulation (EU) 2015/640 but this point is not present in the said regulation. Could you please clarify?
The reference to point 26.320 is an oversight and it will be deleted at the first opportunity.