Embodiment proof
Verifying modification and STC status in a component-history source file
This review confirms that the modification status report inside a component-history source file states only what the file can prove. Each SB, STC, and minor change listed as embodied on or affecting the subject component is checked for three things: that it applies to this serial number, that installation evidence exists, and that the approved data behind it is identified. The check runs during a serialized-component trace review, ahead of any transaction that will rely on the part's configuration standard. It closes with an embodiment exception list separating proven status lines from asserted ones.
When this review is needed
- A component's value depends on a claimed SB standard, and the embodiment entries behind the claim have not been pulled.
- An STC is listed against the part but the file holds neither the permission to use the design data nor the installation record.
- The status report was inherited from a prior operator and carried forward without anyone re-deriving it.
- Interchangeability for an upcoming installation turns on which modification state the part is actually in.
The problem
Modification status reports age badly. Lines get copied from operator to operator, an SB shows as embodied because a kit was purchased, and an STC appears because it was fitted to the fleet even though this serial number was on another wing that month. The report reads authoritatively right up until someone asks for the dirty fingerprints: the task card, the release, the effectivity page showing this part was ever in scope.
What gets reviewed
- Each SB, STC, and modification listed for the component checked for effectivity against its part and serial number
- Embodiment entries traced to the task cards or work orders that performed the change
- Release certificates after modification checked for reference to the change accomplished
- Approved-data identification confirmed for each change, including STC design-data authorization where applicable
- Part-number rolls after modification reconciled with the installed-part list and movement records
- Status lines marked terminated, superseded, or not applicable verified against the current SB revision
Scope this review
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What gets validated
- Every embodied line cites accomplishment evidence physically present in the source file
- Effectivity for each change covers this exact part number and serial number, not just the fleet or model
- Post-modification part numbers on the component agree with those on releases and the equipment records
- STC lines are supported by installation approval and, where required, the data holder's authorization
- No status line rests solely on a kit purchase order or a fleet-level campaign summary
Evidence normally required
- The modification status report for the component as currently maintained
- SB and STC documents at the revisions in effect at embodiment
- The component-history source file with task cards, work orders, and release certificates
- Effectivity data for the subject part and serial number
- The installed-part list reflecting post-modification part numbers
Common discrepancies
- An SB shown embodied on the strength of a campaign record while this serial number was off-wing during the campaign
- STC entries with no installation record and no evidence of authorized design data
- A part number that never rolled after a modification that mandates a new one
- Status lines still citing an SB revision that has since been superseded with changed effectivity
What is at stake
A wrong status line works in both directions and both are expensive. Claiming an unembodied modification invites a misrepresentation dispute at closing; failing to claim an embodied one gives away value the owner already paid for. Either way, once one line proves false the counterparty re-verifies the entire report at the seller's expense in time and leverage.
How the work runs
Baseline the claims
Extract every change listed for the component and fix the revision and effectivity basis for each.
Pull the evidence
Locate accomplishment records, releases, and approved-data references in the source file for each line.
Reconcile part identity
Check post-modification part numbers against the installed-part list and movement records.
Publish the corrected status
Deliver the exception list and a status report restated to what the evidence supports.
What the buyer receives
- An embodiment exception list separating substantiated lines from unsupported ones
- A corrected modification status report the records team can adopt
- A document request list naming the evidence needed to cure each open line
Who uses the output
- Component records leads certifying the configuration standard offered to a counterparty
- Engineering staff assessing interchangeability for the part's next installation
- Lessor and buyer technical teams performing acceptance against the corrected report
How the work fits into the transaction or program
Modification status connects the component trace to configuration control: the equipment list, weight and balance amendments, and even AD applicability all key off which changes are truly embodied. Because of that, exceptions found here propagate into the other record checks in the source review, and this report is usually read together with the equipment-list findings.
Start with a single asset
Confirm release certificates and component traceability are complete.
Jurisdiction-specific considerations
On FAA assets, major alterations bring 14 CFR 43 documentation duties and the field approval or STC basis must be identifiable; AC 21-40 frames how design-approval data supports the installation. EASA-registered history brings Regulation 748/2012 into play, where changes are approved under Part 21 and an STC embodied under one authority may need bilateral acceptance evidence before the status line holds for the other.
Regulatory limits
The review verifies documentation, nothing more. It does not approve modifications, does not decide whether an installation was major or minor, and does not rule on whether a change is acceptable to any authority; it establishes what the file can and cannot demonstrate about the component's modification state.
What this review does not cover
- Physical configuration inspection of the component
- Obtaining STC design-data authorizations from the certificate holder
- Engineering judgment on modification interchangeability or applicability disputes
Specific to this review
- Kit purchase records are the most common false positive in modification status: procurement proves intent, and embodiment lines built on it collapse under one document request.
- A modification accomplished at a shop visit sometimes appears only in the shop report narrative, never on the status report, so unclaimed value hides in the same file as overclaimed lines.
- When a change rolls the part number, every later record that still shows the old number quietly contradicts the status report and will be noticed.
- Cross-registry components carry the extra burden that an embodiment valid under one authority may lack the acceptance evidence the receiving registry expects.
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). Records an owner or operator must keep, including total time in service, current status of life-limited parts, and AD compliance.
Frequently asked questions
The fleet campaign records show the SB done across all aircraft. Does that not cover this part?
Only if this serial number was installed on a campaign aircraft when its embodiment was performed, and the file can show it. Serialized components move, and campaign summaries track aircraft rather than parts. The status line stands on the task card and release for this unit, or it does not stand.
Relevant glossary terms
Related pages
Where this fits
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