Operator certificate transfer
Modification and STC status for an operator AOC transfer
This review checks whether the modification and STC status for an aircraft will carry it onto a new operator's certificate. It is done before handover, for the transferring party, so the modification status report is settled before the receiving side reconciles it against the airframe. The work matches each embodied service bulletin and STC to its approval data and confirms the configuration list reflects what is actually fitted. You get a modification evidence map, a gap list of changes lacking approval or embodiment proof, and a document request set for the STC files and configuration records the receiving operator will want.
When this review is needed
- An aircraft is moving to a new operator certificate and the receiving side will reconcile the configuration list against the airframe.
- An STC was embodied by a prior operator and its approval file did not travel with the aircraft.
- A modification introduced its own continued-airworthiness tasks that must appear in the bridging program.
- The transfer crosses authorities and an STC approved under one regime needs recognition under the other.
The problem
Modifications accumulate quietly over an aircraft's life, and the status report tends to record that a change was embodied without holding the approval that permitted it. At an operator transfer the receiving side reconciles the report against what is actually fitted, and any modification listed without an STC file, or fitted without a listing, becomes a question. Interlinked modifications make it worse, because one change can depend on another whose approval is nowhere in the pack.
What gets reviewed
- Each embodied service bulletin and STC matched to its approval data
- The configuration list reconciled against the modifications actually fitted
- Interdependent modifications checked so each change's prerequisite approvals are present
- Continued-airworthiness tasks introduced by modifications traced into the program
- Effectivity of each modification confirmed for the serial number and configuration
- The modification status report ordered for the receiving side's reconciliation
Scope this review
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What gets validated
- Every modification shown as embodied has approval data identified and on file
- The configuration list has no modification fitted that the report does not record
- Interdependent modifications show the prerequisite approvals each one relies on
- Modification-driven continued-airworthiness tasks appear in the maintenance program
- Effectivity for each change fits the serial number rather than a fleet-level assumption
Evidence normally required
- The modification status report and configuration list for the aircraft
- STC files, service bulletin records, and their approval data
- Embodiment records and work packages closing each modification
- The maintenance program tasks carrying modification-driven requirements
- Contact points at the holders of the STCs embodied on the aircraft
Common discrepancies
- A modification listed as embodied with no STC file or approval data on hand
- A change fitted to the airframe that the configuration list does not record
- An STC whose continued-airworthiness tasks never entered the maintenance program
- An interdependent modification embodied without the prerequisite approval it relies on
What is at stake
A modification the receiving operator cannot tie to approval data unsettles the configuration it is meant to describe, and an unresolved change can stall acceptance or force removal to restore a known state. Modifications that carry their own inspection or life tasks compound the problem, because a missing approval puts those tasks in doubt too. On the transfer clock, tracking down an old STC file leaves little room before the acceptance date.
How the work runs
List embodied changes
Build the modification report from every embodied service bulletin and STC across the airframe and systems.
Match each to approval data
Tie every change to its approval and confirm the configuration list reflects what is fitted.
Resolve the dependencies
Check interlinked modifications for prerequisite approvals and route their tasks into the program.
Deliver map, gaps, and requests
Hand over the modification evidence map, the ranked gap list, and requests for the missing STC files.
What the buyer receives
- A modification evidence map tying each change to its approval and embodiment record
- A gap list of modifications lacking approval or embodiment proof, ranked by configuration weight
- A document request set for the STC files and configuration records still needed
Who uses the output
- Asset managers assessing the exposure of any modification without a filed approval
- Receiving-operator engineering staff reconciling configuration for acceptance
- Records leads assembling STC and embodiment evidence before the transfer window
How the work fits into the transaction or program
This review comes before the receiving operator reconciles the aircraft's configuration. It settles the modifications most likely to draw questions and routes their continued-airworthiness tasks into the bridging program, so the receiving side inherits a configuration list that agrees with the airframe and stands on its approvals.
Start with a single asset
Confirm the status list matches the underlying evidence.
Jurisdiction-specific considerations
An STC approved under FAA rules may need recognition when the aircraft moves to an EASA operator, and a change accepted under one regime is not automatically accepted under the other. The review flags modifications whose approval crosses the authority line, so the receiving side can confirm the basis before the change becomes an acceptance question.
Regulatory limits
The review reports what the modification records and their approval data support. It does not approve a modification or STC, embody a change, evaluate the installed hardware, and does not replace the receiving operator's or authority's acceptance of the configuration.
What this review does not cover
- Approving or embodying any modification or STC
- Physical inspection of installed modifications
- Determining airworthiness of any embodied change
Specific to this review
- The status report tends to record that a change was embodied while the approval that permitted it goes unfiled, and that gap is what the receiving side finds.
- Interdependent modifications fail acceptance together, because one change can rely on a prerequisite approval that is missing from the pack.
- A modification that carries its own inspection or life tasks spreads a missing approval from the configuration into the maintenance program.
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
The modification list looks complete. Why does the receiving operator need the STC files too?
A complete list shows what was fitted, not that each change was approved. The receiving operator reconciles the list against the airframe and asks for the approval behind each modification, so the review confirms those files exist before a change turns into an acceptance question.
Relevant glossary terms
Related pages
Where this fits
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