Registry change ahead
FAA to EASA transfer readiness for modification and STC records
Before an FAA-registered aircraft joins an EASA registry, its modification history has to survive a different reviewer. This review takes the modification status report, the STC files, SB accomplishment records, and the configuration lists and tests each embodied change for an EASA acceptance path, whether through STC validation under the bilateral, an EASA approval already on file, or data the receiving authority can accept. It runs while the transition is being planned and delivers an evidence map for each modification, a gap list, and document requests aimed at what the EASA side will ask for.
When this review is needed
- A sale or lease into an EASA state is in negotiation and the buyer's technical team has asked for the modification status report.
- The aircraft carries US STCs, and nobody has confirmed which of them hold an EASA validation.
- Configuration lists, SB status, and the physical aircraft have drifted apart across prior operators.
- The import timeline depends on knowing early which modifications will need engineering attention.
The problem
Modification records accumulate under whichever authority the aircraft flew, and an FAA fleet history produces a stack of US STCs, 337-documented alterations, and SB entries that were never checked against EASA acceptability. The status report says what was embodied; it says nothing about whether the approval behind each change means anything to the receiving authority. Sorting that out change by change, under a delivery deadline, is what breaks transition schedules.
What gets reviewed
- Every embodied STC checked for an existing EASA validation or an acceptance route under the US-EU bilateral
- Major alterations documented on Form 337 traced to their approved data
- SB accomplishment records reconciled against the modification status report
- Configuration lists compared with modification records to confirm the report reflects the aircraft
- Interfaces between modifications, where one change alters the effectivity or ICA of another
- Supplements to the flight manual and ICA delivered with each change
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What gets validated
- Each line of the modification status report traces to an accomplishment record and an approval reference
- STC certificates on file match the serial-number effectivity and amendment status of what was installed
- EASA validations claimed for a modification are confirmed against the certificate, never against a summary list
- ICA and flight-manual supplements exist for every change that requires them and were incorporated into the operator's program
- Removed or deactivated modifications are closed out in the records instead of lingering as embodied
Evidence normally required
- Modification status report and SB status list
- STC certificates, master data lists, and any EASA validation certificates
- FAA Form 337s with approved data for major alterations
- Configuration and equipment lists as delivered by the current operator
- Flight-manual supplements and ICA associated with embodied changes
Common discrepancies
- US STCs installed for years with no EASA validation and no plan to obtain one
- A modification status report listing changes the configuration records show were later removed
- SB accomplishment entries with no terminating-action evidence where the SB feeds an AD
- Flight-manual supplements missing for installed equipment that changed operating limitations
What is at stake
Each modification without an EASA acceptance path becomes a decision point at import: validate the STC, remove the modification, or re-substantiate the change with acceptable data. All three options cost time and money, and discovering them at the airworthiness review rather than in planning removes any leverage to route the work efficiently. Non-validated changes can also hold up the initial airworthiness review certificate on the new register.
How the work runs
Compile the change inventory
Merge the modification status report, SB status, and configuration lists into one inventory of embodied changes.
Attach approvals and evidence
Link each change to its STC, 337, or SB record and to accomplishment and ICA evidence.
Classify acceptance routes
Sort changes into validated, bilateral-eligible, and case-by-case items with the open questions for each.
Deliver the map and requests
Hand over the evidence map, gap list, and requests directed at the parties holding missing documents.
What the buyer receives
- A modification evidence map: each change, its approval basis, and its EASA acceptance route
- A ranked gap list separating validation questions from missing-document questions
- Document and validation request sets addressed to STC holders, prior operators, and design organizations
Who uses the output
- Continuing-airworthiness managers planning the import airworthiness review
- Asset managers deciding which modifications to validate, keep, or remove before delivery
- Records teams closing the master transition gap list
How the work fits into the transaction or program
Modification status sits at the center of an FAA to EASA transition because it drives the configuration the receiving CAMO must accept and program. Its findings feed the repair review, where alteration and repair data overlap, and the maintenance-program bridge, since embodied changes carry their own ICA into the new program.
Start with a single asset
Confirm the status list matches the underlying evidence.
Jurisdiction-specific considerations
Under the US-EU bilateral and its technical implementation procedures, some FAA STCs are eligible for streamlined EASA validation while others require full review, and the distinction depends on the nature of the change rather than the paperwork volume. Alterations approved by field approval or by DER data alone sit outside the STC framework entirely and are assessed case by case under EU 748/2012. The review classifies each change by which of these routes applies.
Regulatory limits
This is a records assessment. It does not validate STCs, does not approve or classify design changes, and does not decide what the receiving authority will accept. It states what evidence exists, what is missing, and which acceptance route each change appears to fit, so the owner can direct engineering and legal effort where it counts.
What this review does not cover
- STC validation applications or design-organization engineering work
- Physical configuration survey of the aircraft
- Negotiation of modification-related condition items in the transaction documents
Specific to this review
- An STC validation can outlive the aircraft transaction: once obtained, it attaches to the design change, so checking for an existing validation before commissioning a new one saves months.
- The gap between the modification status report and the configuration list is where import reviews stall; reviewers cross-check the two before they read anything else.
- Antenna, connectivity, and cabin-interior changes generate the most non-validated STCs on trading aircraft because they were installed quickly under operator pressure.
- A modification removed years ago but never closed out in the records still has to be explained at import, often with more effort than a properly documented embodied change.
Sources
U.S. Government (eCFR). Maintenance recordkeeping content and approval-for-return-to-service requirements, including 43.9, 43.11, and Appendix B.
U.S. Government (eCFR). Type certificates, STCs (Subpart E), TSO authorizations (Subpart O), PMA (Subpart K), and export airworthiness approvals (Subpart L).
Federal Aviation Administration. STC application process, certification basis, and continued airworthiness obligations of an STC holder.
European Union / EASA. EASA design and production certification, STCs, ETSO authorizations, and EASA Form 1 release.
U.S. Government (eCFR). Export airworthiness approval requirements and special requirements of an importing authority.
Frequently asked questions
Do all US STCs need EASA validation before the aircraft can transfer?
No. Some already hold validations from earlier imports of the same design change, some qualify for streamlined acceptance under the bilateral procedures, and some changes can be removed before delivery instead. The review exists to sort the embodied list into those buckets early, because the full-validation cases set the critical path.
Relevant glossary terms
Related pages
Where this fits
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