STC certification
Certification plan support for an STC program
This review readies the certification plan that frames an STC program, so the basis, affected areas, and review commitments it proposes match what the program can actually deliver. It is run for an aircraft modifier or equipment supplier early, when the plan still shapes the work, or before submittal to confirm the plan and package agree. The work checks that the proposed basis is complete for the modification, that every affected area is captured, and that the plan does not promise coverage the data package will not contain. You receive a gap assessment against the modification's scope, an evidence map from plan commitments to the deliverables that satisfy them, and a closure plan for the commitments the package does not yet meet.
When this review is needed
- The program is starting and the plan needs to define a basis and scope the work can actually hit.
- The modification's effect turned out broader than the plan first assumed and affected areas are missing.
- The plan committed to a means or a review that the evolving data package no longer supports.
- Submittal is near and the plan and the assembled package have to be reconciled before they go in together.
The problem
A certification plan is written before much of the work is understood, so it tends to promise a tidier program than the modification turns out to be. The proposed basis omits a rule the modification actually triggers, an affected area is discovered after the plan is fixed, or a review commitment is made that the schedule and data never catch up to. The plan then becomes a set of promises the package quietly falls short of, and the gap only appears when the two are read side by side at submittal.
What gets reviewed
- The proposed certification basis checked for completeness against what the modification actually triggers
- Affected areas captured so no part of the aircraft the change touches is left out of the plan
- Review and involvement commitments checked against what the schedule and data can support
- The proposed means of compliance aligned with what the evidence stream will produce
- The plan reconciled to the assembled data package where the program is far enough along
- Commitments the package does not yet meet collected into a closure plan
Scope this review
Tell us the asset, the event, and the evidence in scope, and we will outline a focused first engagement.
Identify what is missing against the means of compliance.
What gets validated
- The proposed basis covers every rule the modification triggers, with no thread left unaddressed
- Every area the change affects is identified in the plan, including secondary effects
- Each review commitment in the plan is one the schedule and data package can actually satisfy
- The means proposed for each area matches the evidence the program is set up to generate
- The plan and the current data package agree on scope, basis, and deliverables
Evidence normally required
- The draft certification plan and any prior revisions
- The modification definition and its effect on the aircraft
- The proposed certification basis and any preliminary authority correspondence
- The assembled or planned data package for reconciliation
- The program schedule against which review commitments were made
Common discrepancies
- A rule the modification triggers that the proposed basis does not address
- A secondary affected area discovered after the plan was fixed
- A review commitment the schedule cannot support as written
- A proposed means with no evidence stream set up to produce it
What is at stake
When the plan and package diverge, the authority sees commitments the submittal does not meet, and each unmet commitment becomes a finding or a request that stalls the program. A basis that missed a triggered rule means a whole compliance thread is absent at submittal. An affected area discovered late forces work the schedule never planned, and the modification's approval slips while the plan is reconciled to reality.
How the work runs
Scope the modification
Define what the change actually touches, including secondary effects the plan may have missed.
Test the basis
Confirm the proposed basis covers every rule the modification triggers.
Check the commitments
Verify each review and means commitment matches what the schedule and data can deliver.
Reconcile to the package
Align the plan with the assembled deliverables and plan the closures for what is missing.
What the buyer receives
- A gap assessment of the plan against the modification's true scope and basis
- An evidence map linking each plan commitment to the deliverable that satisfies it
- A closure plan for the commitments and affected areas the package does not yet cover
Who uses the output
- Certification leads who own the plan and its commitments to the authority
- STC program managers scoping the work and schedule against what the plan promises
- Engineering leads confirming the affected areas and means match the modification
How the work fits into the transaction or program
The certification plan sets the frame the rest of the program fills in, so this review is most useful early, when the plan still steers the work, and again before submittal to confirm the plan and package agree. It defines the basis the compliance matrix indexes and the means the evidence stream produces, so a plan that misses a rule or an affected area propagates into every document downstream.
Start with a single asset
Reduce finding cycles by checking the package first.
Jurisdiction-specific considerations
An STC planned for both FAA and EASA acceptance has to account for a basis and involvement expectations that differ between the two, so the review keeps the plan honest about which commitments belong to which authority rather than assuming one plan satisfies both without adjustment.
Regulatory limits
The review checks the plan against the modification's scope and the package it promises. It does not approve the certification basis, commit the authority to a level of involvement, or grant the STC.
What this review does not cover
- Negotiating the certification basis or the authority's involvement level
- Performing the engineering that closes an affected area
- Any authority acceptance of the plan or the STC
Specific to this review
- A certification plan is written before the work is fully understood, so it tends to describe a simpler program than the modification proves to be.
- A basis that misses a triggered rule removes an entire compliance thread from the program, and the gap stays invisible until the missing thread is looked for at submittal.
- Affected areas discovered after the plan is fixed are the usual source of unplanned work, because a secondary effect of the change was not traced when the plan was written.
Sources
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.
RTCA. Environmental qualification test categories and procedures referenced by TSO and equipment qualification.
Federal Aviation Administration. FAA type certification process, certification basis establishment, and compliance findings.
Frequently asked questions
Is it too late to review the plan once the program is underway?
No. Early is best, because the plan still shapes the work, but a mid-program review catches the divergence between what the plan promised and what the package is actually producing. Reconciling the two before submittal is far cheaper than having the authority find the gap and reopen the scope.
Relevant glossary terms
Related pages
Where this fits
Talk to an engineer who has done this work
We will walk through your current state, the records or evidence involved, and a scoped first engagement.
Talk through the aircraft, records, evidence, deadline, and next useful step.