Modification & STC status
ATR 72 modification and STC status records review
This review reconciles the modifications and STCs an ATR 72 carries against the approval data and configuration records that should support each one. A records specialist runs it before a transaction, after a modification campaign, or when embodiment history has accumulated across operators. It checks Service Bulletin embodiment, STC files, configuration lists, and the approval basis behind each change, then flags modifications recorded without support or embodied without a record. You receive a reconciled modification status, a list of unsupported or mis-recorded changes, and the approval evidence assembled for each embodiment.
When this review is needed
- An ATR 72 has accumulated modifications across operators and no one has reconciled the status recently.
- A modification campaign or SB embodiment just finished and the records have to catch up to the airframe.
- A buyer needs the STC and modification configuration confirmed before pricing the asset.
- An STC is claimed on the aircraft but its approval file has never been located.
The problem
Modification status drifts because each change is small and the record for it lives somewhere other than the status list. An SB gets embodied but recorded against the wrong revision, an STC is fitted under one operator and its approval file stays behind at redelivery, or an equipment change never gets logged as the modification the type treats it as. On an ATR 72 configured for a specific regional role, cabin, avionics, and role-equipment modifications are where the record most often lags the aircraft.
What gets reviewed
- Service Bulletin embodiment checked against the correct revision and applicability for the serial number
- STC installations reconciled to their approval files and configuration effect
- Modification records matched to the approved or acceptable data that authorizes each change
- Configuration lists reconciled to the modifications the records claim are embodied
- Equipment changes checked for treatment as modifications where the type requires it
- Overlapping or superseding modifications resolved to a single current configuration
Scope this review
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What gets validated
- Each embodied SB carries the revision and applicability that apply to this aircraft
- Every claimed STC has an approval file that matches the installation on the aircraft
- Modification records reference approval data appropriate to the change and jurisdiction
- The configuration list and the modification status agree on what is embodied
- Superseded modifications are marked so the current configuration is unambiguous
Evidence normally required
Common discrepancies
- An SB recorded as embodied against a revision that does not apply to this serial number
- An STC installed on the aircraft with no approval file transferred to support it
- An equipment change made and flown but never recorded as the modification the type requires
- A superseded modification still shown as current, so the configuration reads two ways
What is at stake
A modification without traceable approval data can force removal or re-substantiation, which is expensive and slow compared with confirming the basis up front. A status list that overstates or understates embodiment sends the wrong AD applicability downstream, and an STC claimed without its file behind it stalls acceptance until the approval is reconstructed.
Move from findings to resolution
Move from findings to a documented resolution path.
How the work runs
Pull the claimed status
Assemble the modification, STC, and SB embodiment the records assert for the serial number.
Match change to basis
Confirm each change carries approval data that applies to this aircraft and jurisdiction.
Reconcile to configuration
Check the configuration list and the modification status agree on what is embodied.
Flag the exceptions
List unsupported, mis-recorded, and superseded changes with the evidence behind each.
What the buyer receives
- A reconciled modification and STC status tied to the current configuration
- A list of unsupported, mis-recorded, or superseded changes with the issue on each
- The approval evidence assembled behind each confirmed embodiment
Who uses the output
- Records teams setting a modification baseline the configuration file rests on
- Engineering deciding how to treat a modification with no traceable approval basis
- Asset and acquisition teams pricing the configuration the records actually support
How the work fits into the transaction or program
Modification status sits under AD applicability and configuration control, so it is reconciled before those depend on it. The confirmed status feeds a configuration baseline, and any modification without a traceable basis feeds remediation before it reaches a data room or a redelivery binder.
Aircraft-specific considerations
ATR 72 airframes are frequently modified for their regional role, so cabin reconfiguration, avionics upgrades, and role equipment dominate the modification record more than on a standard narrowbody. These changes cross STC and SB territory and often move between operators, which is where the approval file most commonly gets left behind and the status list overstates what the aircraft can support.
Jurisdiction-specific considerations
An ATR 72 modified under one authority and traded to another carries STC and SB approvals whose acceptance does not automatically transfer, so the review flags where an FAA STC needs an EASA validation, or the reverse, before the configuration is complete in the receiving system.
Regulatory limits
The review confirms the recorded modification status is internally consistent and supported by approval data. It does not approve a modification, grant or validate an STC, or determine that the installed configuration is airworthy.
What this review does not cover
- Developing, approving, or validating any modification or STC data
- A physical configuration survey of the installed modifications
- Any airworthiness determination on the modified configuration
Specific to this review
- STC approval files are the record most often left behind at redelivery, which is why the claim and the file are checked separately.
- Regional role modifications dominate the ATR 72 record, so cabin and avionics changes are where the status list drifts most.
- A superseded modification shown as current is a silent contradiction that sends the wrong AD applicability downstream.
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
An STC is installed but we cannot find the approval file. What now?
The review records it as a claimed modification without a traceable basis and routes it to remediation, where the file is chased from the operator or shop that embodied it. If the approval genuinely cannot be recovered, the change may have to be re-substantiated or removed, which is why locating the file early matters.
Relevant glossary terms
Related pages
Where this fits
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